text:
sh-posix(1) sh-posix(1)
sh, rsh - standard and restricted POSIX.2-conformant command shells
sh [{-|+}aefhikmnprstuvx] [{-|+}o option]... [-c string] arg]...
rsh [{-|+}aefhikmnprstuvx] [{-|+}o option]... [-c string] [arg]...
This shell is intended to conform to the shell specification of the
POSIX.2 Shell and Utility standards. Check any standards conformance
documents shipped with your system for information on the conformance
of this shell to any other standards.
List of Subheadings in DESCRIPTION
Shell Invocation Tilde Substitution Environment
Options Command Substitution Functions
rsh Restrictions Parameter Substitution Jobs
Definitions Blank Interpretation Signals
Commands File Name Generation Execution
Simple Commands Quoting Command Reentry
Compound Commands Arithmetic Evaluation Command Line Editing
Special Commands Prompting emacs Editing Mode
Comments Conditional Expressions vi Editing Mode
Aliasing Input/Output
sh is a command programming language that executes commands read from
a terminal or a file.
rsh is a restricted version of sh. See the "rsh Restrictions"
subsection below.
Shell Invocation
If the shell is invoked by an exec*() system call and the first
character of argument zero (shell parameter 0) is dash (-), the shell
is assumed to be a login shell and commands are read first from
/etc/profile, then from either .profile in the current directory or
$HOME/.profile if either file exists, and finally from the file named
by performing parameter substitution on the value of the environment
parameter ENV, if the file exists. If the -s option is not present
and an arg is, a path search is performed on the first arg to
determine the name of the script to execute. When running sh with
arg, the script arg must have read permission and any setuid and
setgid settings will be ignored. Commands are read as described
Shell output, except for the output of some of the commands listed in
the "Special Commands" subsection, is written to standard error (file
descriptor 2).
Hewlett-Packard Company - 1 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
The following options are interpreted by the shell when it is invoked.
-c string Read commands from string.
-i If -i is present or if the shell input and output are
attached to a terminal (as reported by tty()), the
shell is interactive. In this case SIGTERM is ignored
and SIGINT is caught and ignored (so that wait is
interruptible). In all cases, SIGQUIT is ignored by
the shell. See signal(5).
-r The shell is a restricted shell.
-s If -s is present or if no arguments remain, commands
are read from the standard input.
The remaining options and arguments are described under the set
command in the "Special Commands" subsection.
rsh Restrictions
rsh is used to set up login names and execution environments where
capabilities are more controlled than those of the standard shell.
The actions of rsh are identical to those of sh, except that the
following are forbidden:
+ Changing directory (see the cd special command and cd(1))
+ Setting the value of SHELL, ENV, or PATH
+ Specifying path or command names containing /
+ Redirecting output (>>>>, >>>>|, <<<<>>>>, and >>>>>>>>)
The restrictions above are enforced after the .profile and ENV files
are interpreted.
When a command to be executed is found to be a shell procedure, rsh
invokes sh to execute it. Thus, the end-user is provided with shell
procedures accessible to the full power of the standard shell, while
being restricted to a limited menu of commands. This scheme assumes
that the end-user does not have write and execute permissions in the
same directory.
These rules effectively give the writer of the .profile file complete
control over user actions, by performing guaranteed set-up actions and
leaving the user in an appropriate directory (probably not the login
The system administrator often sets up a directory of commands
(usually /usr/rbin) that can be safely invoked by rsh. HP-UX systems
provide a restricted editor red (see ed(1)), suitable for restricted
Hewlett-Packard Company - 2 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
metacharacter One of the following characters:
; &&&& ( ) | <<<< >>>> newline space tab
blank A tab or a space.
identifier A sequence of letters, digits, or underscores
starting with a letter or underscore. Identifiers
are used as names for functions and named
word A sequence of characters separated by one or more
nonquoted metacharacters.
command A sequence of characters in the syntax of the
shell language. The shell reads each command and
carries out the desired action, either directly or
by invoking separate utilities.
special command A command that is carried out by the shell without
creating a separate process. Except for
documented side effects, most special commands can
be implemented as separate utilities.
# Comment delimiter. A word beginning with # and
all following characters up to a newline are
parameter An identifier, a decimal number, or one of the
characters !, #, $, *, -, ?, @, and _. See the
"Parameter Substitution" subsection.
named parameter A parameter that can be assigned a value. See the
"Parameter Substitution" subsection.
variable A parameter.
environment variable
A parameter that is known outside the local shell,
usually by means of the export special command.
A command can be a simple command that executes an executable file, a
special command that executes within the shell, or a compound command
that provides flow of control for groups of simple, special, and
compound commands.
Simple Commands
A simple command is a sequence of blank-separated words that may be
preceded by a parameter assignment list. (See the "Environment"
Hewlett-Packard Company - 3 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
subsection). The first word specifies the name of the command to be
executed. Except as specified below, the remaining words are passed
as arguments to the invoked command. The command name is passed as
argument 0 (see exec(2)). The value of a simple-command is its exit
status if it terminates normally, or 128+errorstatus if it terminates
abnormally (see signal(5) for a list of errorstatus values).
A pipeline is a sequence of one or more commands separated by a bar
(|) and optionally preceded by an exclamation mark (!). The standard
output of each command but the last is connected by a pipe (see
pipe(2)) to the standard input of the next command. Each command is
run as a separate process; the shell waits for the last command to
terminate. If ! does not precede the pipeline, the exit status of the
pipeline is the exit status of the last command in the pipeline.
Otherwise, the exit status of the pipeline is the logical negation of
the exit status of the last command in the pipeline.
A list is a sequence of one or more pipelines separated by ;, &&&&, &&&&&&&&,
or ||, and optionally terminated by ;, &&&&, or |&&&&.
; Causes sequential execution of the preceding pipeline. An
arbitrary number of newlines can appear in a list, instead
of semicolons, to delimit commands.
&&&& Causes asynchronous execution of the preceding pipeline
(that is, the shell does not wait for that pipeline to
|&&&& Causes asynchronous execution of the preceding command or
pipeline with a two-way pipe established to the parent
shell. The standard input and output of the spawned command
can be written to and read from by the parent shell using
the -p option of the special commands read and print.
&&&&&&&& Causes the list following it to be executed only if the
preceding pipeline returns a zero value.
|| Causes the list following it to be executed only if the
preceding pipeline returns a nonzero value.
Of these five symbols, ;, &&&&, and |&&&& have equal precedence, which is
lower than that of &&&&&&&& and ||. The symbols &&&&&&&& and || also have equal
Compound Commands
Unless otherwise stated, the value returned by a compound command is
that of the last simple command executed in the compound command. The
; segment separator can be replaced by one or more newlines.
The following keywords are recognized only as the first word of a
command and when not quoted:
Hewlett-Packard Company - 4 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
! } elif for then
[[ case else function time
]] do esac if until
{ done fi select while
A compound command is one of the following.
case word in [[;] [(] pattern [| pattern]...) list ;;]... ; esac
Execute the list associated with the first pattern that matches
word. The form of the patterns is identical to that used for
file name generation (see the "File Name Generation" subsection).
The ;; case terminator cannot be replaced by newlines.
for identifier [in word ...] ; do list ; done
Set identifier to each word in sequence and execute the do list.
If in word ... is omitted, set identifier to each set positional
parameter instead. See the "Parameter Substitution" subsection.
Execution ends when there are no more positional parameters or
words in the list.
function identifier { list ; }
identifier () { list ; }
Define a function named by identifier. A function is called by
executing its identifier as a command. The body of the function
is the list of commands between { and }. See the "Functions"
if list ; then list ; [elif list ; then list ;]... [else list ;] fi
Execute the if list and, if its exit status is zero, execute the
first then list. Otherwise, execute the elif list (if any) and,
if its exit status is zero, execute the next then list. Failing
that, execute the else list (if any). If no else list or then
list is executed, if returns a zero exit status.
select identifier [in word ...] ; do list ; done
Print the set of words on standard error (file descriptor 2),
each preceded by a number. If in word ... is omitted, print the
positional parameters instead (see the "Parameter Substitution"
subsection). Print the PS3 prompt and read a line from standard
input into the parameter REPLY. If this line consists of the
number of one of the listed words, set identifier to the
corresponding word, execute list, and repeat the PS3 prompt. If
the line is empty, print the selection list again, and repeat the
PS3 prompt. Otherwise, set identifier to null, execute list, and
repeat the PS3 prompt. The select loop repeats until a break
special command or end-of-file is encountered.
Hewlett-Packard Company - 5 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
time pipeline
Execute the pipeline and print the elapsed time, the user time,
and the system time on standard error. Note that the time
keyword can appear anywhere in the pipeline to time the entire
pipeline. To time a particular command in a pipeline, see
until list ; do list ; done
Execute the until list. If the exit status of the last command
in the list is nonzero, execute the do list and execute the until
list again. When the exit status of the last command in the
until list is zero, terminate the loop. If no commands in the do
list are executed, until returns a zero exit status.
while list ; do list ; done
Execute the while list. If the exit status of the last command
in the list is zero, execute the do list and execute the while
list again. When the exit status of the last command in the
while list is nonzero, terminate the loop. If no commands in the
do list are executed, while returns a nonzero exit status.
( list )
Execute list in a separate environment. If two adjacent open
parentheses are needed for nesting, a space must be inserted
between them to avoid arithmetic evaluation.
{ list ; }
Execute list, but not in a separate environment. Note that { is
a keyword and requires a trailing blank to be recognized.
[[ expression ]]
Evaluate expression and return a zero exit status when expression
is true. See the "Conditional Expressions" subsection for a
description of expression. Note that [[ and ]] are keywords and
require blanks between them and expression.
Special Commands
Special commands are simple commands that are executed in the shell
process. They permit input/output redirection. Unless otherwise
indicated, file descriptor 1 (standard output) is the default output
location and the exit status, when there are no syntax errors, is
Commands that are marked with % are treated specially in the following
Hewlett-Packard Company - 6 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
1. Variable assignment lists preceding the command remain in
effect when the command completes.
2. I/O redirections are processed after variable assignments.
3. Errors cause a script that contains them to abort.
Words following commands marked with & that are in the format of a
variable assignment are expanded with the same rules as a variable
assignment. This means that tilde substitution is performed after the
= sign and word-splitting and file-name generation are not performed.
% : [arg]...
(colon) Only expand parameters. A zero exit status is returned.
% . file [arg]...
(period) Read and execute commands from file and return. The
commands are executed in the current shell environment. The
search path specified by PATH is used to find the directory
containing file. If any arguments arg are given, they become the
positional parameters. Otherwise, the positional parameters are
unchanged. The exit status is the exit status of the last
command executed.
& alias [-tx] [name[=value]]...
With name=value specified, define name as an alias and assign it
the value value. A trailing space in value causes the next word
to be checked for alias substitution.
With name=value omitted, print the list of aliases in the form
name=value on standard output.
With name specified without =value, print the specified alias.
With -t, set tracked aliases. The value of a tracked alias is
the full path name corresponding to the given name. The value of
a tracked alias becomes undefined when the value of PATH is
reset, but the alias remains tracked. With name=value omitted,
print the list of tracked aliases in the form name=pathname on
standard output.
With -x, set exported aliases. An exported alias is defined
across subshell environments. With name=value omitted, print the
list of exported aliases in the form name=value on standard
Alias returns true unless a name is given for which no alias has
been defined.
Hewlett-Packard Company - 7 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
bg [job]...
Put the specified jobs into the background. The current job is
put in the background if job is unspecified. See the "Jobs"
subsection for a description of the format of job.
% break [n]
Exit from the enclosing for, select, until, or while loop, if
any. If n is specified, exit from n levels.
cd [-L|-P] [arg]
cd old new
In the first form, change the current working directory (PWD) to
arg. If arg is -, the directory is changed to the previous
directory (OLDPWD).
With -L (default), preserve logical naming when treating symbolic
links. cd -L .. moves the current directory one path component
closer to the root directory.
With -P, preserve the physical path when treating symbolic links.
cd -P .. changes the working directory to the actual parent
directory of the current directory.
The shell parameter HOME is the default arg. The parameter PWD
is set to the current directory.
The shell parameter CDPATH defines the search path for the
directory containing arg. Alternative directory names are
separated by a colon (:). If CDPATH is null or undefined, the
default value is the current directory. Note that the current
directory is specified by a null path name, which can appear
immediately after the equal sign or between the colon delimiters
anywhere else in the path list. If arg begins with a /, the
search path is not used. Otherwise, each directory in the path
is searched for arg. See also cd(1).
The second form of cd substitutes the string new for the string
old in the current directory name, PWD, and tries to change to
this new directory.
command [arg]...
Treat arg as a command, but disable function lookup on arg. See
command(1) for usage and description.
Hewlett-Packard Company - 8 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
% continue [n]
Resume the next iteration of the enclosing for, select, until, or
while loop. If n is specified, resume at the nth enclosing loop.
echo [arg]...
Print arg on standard output. See echo(1) for usage and
description. See also the print special command.
% eval [arg]...
Read the arguments as input to the shell and execute the
resulting commands. Allows parameter substitution for keywords
and characters that would otherwise be unrecognized in the
resulting commands.
% exec [arg]...
Parameter assignments remain in effect after the command
completes. If arg is given, execute the command specified by the
arguments in place of this shell without creating a new process.
Input/output arguments may appear and affect the current process.
If no arguments are given, modify file descriptors as prescribed
by the input/output redirection list. In this case, any file
descriptor numbers greater than 2 that are opened with this
mechanism are closed when another program is invoked.
% exit [n]
Exit from the shell with the exit status specified by n. If n is
omitted, the exit status is that of the last command executed.
An end-of-file also causes the shell to exit, except when a shell
has the ignoreeof option set. (See the set special command.)
%& export [name[=value]]...
%& export -p
Mark the given variable names for automatic export to the
environment of subsequently executed commands. Optionally,
assign values to the variables.
With -p, write the names and values of all exported variables to
standard output, in a format with the proper use of quoting, so
that it is suitable for re-input to the shell as commands that
achieve the same exporting results.
Hewlett-Packard Company - 9 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
fc [-r] [-e ename] [first [last]]
fc -l [-nr] [first [last]]
fc -s [old=new] [first]
fc -e - [old=new] [command]
List, or edit and reexecute, commands previously entered to an
interactive shell. A range of commands from first to last is
selected from the last HISTSIZE commands typed at the terminal.
The arguments first and last can be specified as a number or
string. A given string is used to locate the most recent
command. A negative number is used to offset the current command
With -l, list the commands on standard output. Without -l,
invoke the editor program ename on a file containing these
keyboard commands. If ename is not supplied, the value of the
parameter FCEDIT (default /usr/bin/ed) is used as the editor.
Once editing has ended, the commands (if any) are executed. If
last is omitted, only the command specified by first is used. If
first is not specified, the default is the previous command for
editing and -16 for listing.
With -r, reverse the order of the commands.
With -n, suppress command numbers when listing.
With -s, reexecute the command without invoking an editor.
The old=new argument replaces the first occurrence of string old
in the command to be reexecuted by the string new.
fg [job]...
Bring each job into the foreground in the order specified. If no
job is specified, bring the current job into the foreground. See
the "Jobs" subsection for a description of the format of job.
getopts optstring name [arg]...
Parse the argument list, or the positional parameters if no
arguments, for valid options. On each execution, return the next
option in name. See getopts(1) for usage and description.
An option begins with a + or a -. An argument not beginning with
+ or -, or the argument --, ends the options. optstring contains
the letters that getopts recognizes. If a letter is followed by
a :, that option is expected to have an argument. The options
can be separated from the argument by blanks.
For an option specified as -letter, name is set to letter. For
an option specified as +letter, name is set to +letter. The
Hewlett-Packard Company - 10 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
index of the next arg is stored in OPTIND. The option argument,
if any, is stored in OPTARG. If no option argument is found, or
the option found does not take an argument, OPTARG is unset.
A leading : in optstring causes getopts to store the letter of an
invalid option in OPTARG, and to set name to ? for an unknown
option and to : when a required option argument is missing.
Otherwise, getopts prints an error message. The exit status is
nonzero when there are no more options.
& hash [utility]...
& hash -r
Affect the way the current shell environment remembers the
locations of utilities. With utility, add utility locations to a
list of remembered locations. With no arguments, print the
contents of the list. With -r, forget all previously remembered
utility locations.
jobs [-lnp] [job]...
List information about each given job, or all active jobs if job
is not specified. With -l, list process IDs in addition to the
normal information. With -n, display only jobs that have stopped
or exited since last notified. With -p, list only the process
group. See the "Jobs" subsection for a description of the format
of job.
kill [-s signal] process ...
kill -l
kill [-signal] process ...
Send either signal 15 (SIGTERM, terminate) or the specified
signal to the specified jobs or processes. See kill(1) for usage
and description.
With -l, list the signal names and numbers.
let arg ...
(( arg ...))
Evaluate each arg as a separate arithmetic expression. See the
"Arithmetic Evaluation" subsection for a description of
arithmetic expression evaluation. The exit status is 0 if the
value of the last expression is nonzero, and 1 otherwise.
% newgrp [-] [group]
Replace the current shell with a new one having group as the
user's group. The default group is the user's login group. With
-, the user's .profile and $ENV files are also executed. See
Hewlett-Packard Company - 11 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
newgrp(1) for usage and description. Equivalent to
exec newgrp arg ....
print [-nprRsu[n]] [arg]...
The shell output mechanism. With no options or with option - or
--, print the arguments on standard output as described in
echo(1). See also printf(1).
With -n, do not add a newline character to the output.
With -p, write the arguments onto the pipe of the process spawned
with |&&&& instead of standard output.
With -R or -r (raw mode), ignore the escape conventions of echo.
With -R, print all subsequent arguments and options other than
With -s, write the arguments into the history file instead of to
standard output.
With -u, specify a one-digit file descriptor unit number n on
which the output will be placed. The default is 1 (standard
pwd [-L|-P]
Print the name of the current working directory (equivalent to
print -r - $PWD). With -L (the default), preserve the logical
meaning of the current directory. With -P, preserve the physical
meaning of the current directory if it is a symbolic link. See
also the cd special command, cd(1), ln(1), and pwd(1).
read [-prsu[n]] [name?prompt] [name]...
The shell input mechanism. Read one line (by default, from
standard input) and break it up into words using the characters
in IFS as separators. The first word is assigned to the first
name, the second word to the second name, and so on; the
remaining words are assigned to the last name. See also read(1).
The return code is 0, unless an end-of-file is encountered.
With -p, take the input line from the input pipe of a process
spawned by the shell using |&&&&. An end-of-file with -p causes
cleanup for this process so that another process can be spawned.
With -r (raw mode), a \ at the end of a line does not signify
line continuation.
With -s, save the input as a command in the history file.
Hewlett-Packard Company - 12 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
With -u, specify a one-digit file descriptor unit to read from.
The file descriptor can be opened with the exec special command.
The default value of n is 0 (standard input). If name is
omitted, REPLY is used as the default name.
If the first argument contains a ?, the remainder of the argument
is used as a prompt when the shell is interactive.
If the given file descriptor is open for writing and is a
terminal device, the prompt is placed on that unit. Otherwise,
the prompt is issued on file descriptor 2 (standard error).
%& readonly [name[=value]]...
%& readonly -p
Mark the given names read only. These names cannot be changed by
subsequent assignment.
With -p, write the names and values of all read-only variables to
standard output in a format with the proper use of quoting so
that it is suitable for re-input to the shell as commands that
achieve the same attribute-setting results.
% return [n]
Cause a shell function to return to the invoking script with the
return status specified by n. If n is omitted, the return status
is that of the last command executed. Only the low 8 bits of n
(decimal 0 to 255) are passed back to the caller. If return is
invoked while not in a function or a . script (see the . special
command), it has the same effect as an exit command.
% set [{-|+}abCefhkmnopstuvx] [{-|+}o option]... [{-|+}A
name] [arg]...
Set (-) or clear (+) execution options or perform array
assignments (-A, +A). All options except -A and +A can be
supplied in a shell invocation (see the SYNOPSIS section and the
"Shell Invocation" subsection).
Using + instead of - before an option causes the option to be
turned off. These options can also be used when invoking the
shell. The current list of set single-letter options is
contained in the shell variable -. It can be examined with the
command echo $-.
The - and + options can be intermixed in the same command, except
that there can be only one -A or +A option.
Unless -A or +A is specified, the remaining arg arguments are
assigned consecutively to the positional parameters 1, 2, ....
Hewlett-Packard Company - 13 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
The set command with neither arguments nor options displays the
names and values of all shell parameters on standard output. See
also env(1).
The options are defined as follows.
-A Array assignment. Unset the variable name and assign values
sequentially from the list arg. With +A, do not unset the
variable name first.
-a Automatically export subsequently defined parameters.
-b Cause the shell to notify the user asynchronously of
background jobs as they are completed. When the shell
notifies the user that a job has been completed, it can
remove the job's process ID from the list of those known in
the current shell execution environment.
-C Prevent redirection >>>> from truncating existing files.
Requires >>>>| to truncate a file when turned on.
-e Execute the ERR trap, if set, and exit if a command has a
nonzero exit status, and is not part of the compound list
following a if, until, or while keyword, and is not part of
an AND or OR list, and is not a pipeline preceded by the !
reserved word. This mode is disabled while reading
-f Disable file name generation.
-h Specify that each command whose name is an identifier
becomes a tracked alias when first encountered.
-k Place all parameter assignment arguments (not just those
that precede the command name) into the environment for a
-m Run background jobs in a separate process group and print a
line upon completion. The exit status of background jobs is
reported in a completion message. This option is turned on
automatically for interactive shells.
-n Read commands and check them for syntax errors, but do not
execute them. The -n option is ignored for interactive
-o Set an option argument from the following list. Repeat the
-o option to specify additional option arguments.
allexport Same as -a.
Hewlett-Packard Company - 14 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
bgnice Run all background jobs at a lower priority.
errexit Same as -e.
emacs Use a emacs-style inline editor for command
gmacs Use a gmacs-style inline editor for command
ignoreeof Do not exit from the shell on end-of-file
(eof as defined by stty; default is ^D). The
exit special command must be used.
keyword Same as -k.
markdirs Append a trailing / to all directory names
resulting from file name generation.
monitor Same as -m.
noclobber Same as -C.
noexec Same as -n.
noglob Same as -f.
nolog Do not save function definitions in history
notify Same as -b.
nounset Same as -u.
privileged Same as -p.
verbose Same as -v.
trackall Same as -h.
vi Use a vi-style inline editor for command
viraw Process each character as it is typed in vi
mode (always on).
xtrace Same as -x.
-p Disable processing of the $HOME/.profile file and uses the
file /etc/suid_profile instead of the ENV file. This mode
is on whenever the effective user ID (group ID) is not equal
to the real user ID (group ID). Turning this off causes the
effective user ID and group ID to be set to the real user ID
and group ID.
-s Sort the positional parameters.
-t Exit after reading and executing one command.
-u Treat unset parameters as an error when substituting.
-v Print shell input lines as they are read.
-x Print commands and their arguments as they are executed.
- Turn off -x and -v options and stop examining arguments for
-- Do not change any of the options; useful in setting
parameter 1 to a value beginning with -. If no arguments
Hewlett-Packard Company - 15 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
follow this option, the positional parameters are unset.
% shift [n]
Rename the positional parameters from n+1 ... to 1 .... The
default value of n is 1. n can be any arithmetic expression that
evaluates to a nonnegative number less than or equal to $#.
test [expr]
Evaluate conditional expression expr. See test(1) for usage and
description. The arithmetic comparison operators are not
restricted to integers. They allow any arithmetic expression.
The following additional primitive expressions are allowed:
-L file True if file is a symbolic link.
-e file True if file exists.
file1 -nt file2 True if file1 is newer than file2.
file1 -ot file2 True if file1 is older than file2.
file1 -ef file2 True if file1 has the same device and
i-node number as file2.
% times
Print the accumulated user and system times for the shell and for
processes run from the shell.
% trap [arg] [sig]...
Set arg as a command that is read and executed when the shell
receives a sig signal. (Note that arg is scanned once when the
trap is set and once when the trap is taken.) Each sig can be
given as the number or name of a signal. Letter case is ignored.
For example, 3, QUIT, quit, and SIGQUIT all specify the same
signal. Use kill -l to get a list of signals.
Trap commands are executed in signal number order. Any attempt
to set a trap on a signal that was ignored upon entering the
current shell is ineffective. Traps remain in effect for a given
shell until explicitly changed with another trap command; that
is, a trap set within a function will remain in effect even after
the function returns.
If arg is - (or if arg is omitted and the first sig is numeric),
reset all traps for each sig to their original values.
If arg is the null string ('' or ""), each sig is ignored by the
shell and by the commands it invokes.
If sig is DEBUG, then arg is executed after each command. If sig
is ERR, arg is executed whenever a command has a nonzero exit
Hewlett-Packard Company - 16 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
code. If sig is 0 or EXIT, the command arg is executed on exit
from the shell.
With no arguments, print a list of commands associated with each
signal name.
& typeset [{-|+}LRZfilrtux[n]] [name[=value]]...
name=value [name=value]...
Assign types and a value to a local named parameter name. See
also the export special command. Parameter assignments remain in
effect after the command completes. When invoked inside a
function, create a new instance of the parameter name. The
parameter value and type are restored when the function
The following list of attributes can be specified. Use + instead
of - to turn the options off.
-L Left justify and remove leading blanks from value. If n is
nonzero, it defines the width of the field; otherwise, it is
determined by the width of the value of first assignment.
When name is assigned, the value is filled on the right with
blanks or truncated, if necessary, to fit into the field.
Leading zeros are removed if the -Z option is also set. The
-R option is turned off. Flagged as leftjust n.
-R Right justify and fill with leading blanks. If n is
nonzero, it defines the width of the field; otherwise, it is
determined by the width of the value of first assignment.
The field is left-filled with blanks or truncated from the
end if the parameter is reassigned. The -L option is turned
off. Flagged as rightjust n.
-Z Right justify and fill with leading zeros if the first
nonblank character is a digit and the -L option has not been
set. If n is nonzero it defines the width of the field;
otherwise, it is determined by the width of the value of
first assignment. Flagged as zerofill n plus the flag for
-L or -R.
-f Cause name to refer to function names rather than parameter
names. No assignments can be made to the name declared with
the typeset statement. The only other valid options are -t
(which turns on execution tracing for this function) and -x
(which allows the function to remain in effect across shell
procedures executed in the same process environment).
Flagged as function.
-i Parameter is an integer. This makes arithmetic faster. If
n is nonzero it defines the output arithmetic base;
Hewlett-Packard Company - 17 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
otherwise, the first assignment determines the output base.
Flagged as integer [base n].
-l Convert all uppercase characters to lowercase. The
uppercase -u option is turned off. Flagged as lowercase.
-r Mark any given name as "read only". The name cannot be
changed by subsequent assignment. Flagged as readonly.
-t Tag the named parameters. Tags are user-definable and have
no special meaning to the shell. Flagged as tagged.
-u Convert all lowercase characters to uppercase characters.
The lowercase -l option is turned off. Flagged as
-x Mark any given name for automatic export to the environment
of subsequently executed commands. Flagged as export.
typeset alone displays a list of parameter names, prefixed by any
flags specified above.
typeset - displays the parameter names followed by their values.
Specify one or more of the option letters to restrict the list.
Some options are incompatible with others.
typeset + displays the parameter names alone. Specify one or
more of the option letters to restrict the list. Some options
are incompatible with others.
ulimit [-HSacdfnst] [limit]
Set or display a resource limit. The limit for a specified
resource is set when limit is specified. The value of limit can
be a number in the unit specified with each resource, or the
keyword unlimited.
The -H and -S flags specify whether the hard limit or the soft
limit is set for the given resource. A hard limit cannot be
increased once it is set. A soft limit can be increased up to
the hard limit. If neither -H nor -S is specified, the limit
applies to both. The current resource limit is printed when
limit is omitted. In this case, the soft limit is printed unless
-H is specified. When more than one resource is specified, the
limit name and unit are printed before the value.
If no option is given, -f is assumed.
-a List all of the current resource limits.
-c The number of 512-byte blocks in the size of core
Hewlett-Packard Company - 18 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
-d The number of kilobytes in the size of the data area.
-f The number of 512-byte blocks in files written by child
processes (files of any size can be read).
-n The number of file descriptors.
-s The number of kilobytes in the size of the stack area.
-t The number of seconds to be used by each process.
umask [-S] [mask]
Set the user file-creation mask mask. mask can be either an
octal number or a symbolic value as described in umask(1). A
symbolic value shows permissions that are unmasked. An octal
value shows permissions that are masked off.
Without mask, print the current value of the mask. With -S,
print the value in symbolic format. Without -S, print the value
as an octal number. The output from either form can be used as
the mask of a subsequent invocation of umask.
unalias name ...
unalias -a
Remove each name from the alias list. With -a, remove all alias
definitions from the current shell execution environment.
% unset [-fv] name ...
Remove the named shell parameters from the parameter list. Their
values and attributes are erased. Read-only variables cannot be
unset. With -f, names refer to function names. With -v, names
refer to variable names. Unsetting _, ERRNO, LINENO, MAILCHECK,
OPTARG, OPTIND, RANDOM, SECONDS, and TMOUT removes their special
meaning, even if they are subsequently assigned to.
wait [job]
Wait for the specified job to terminate or stop, and report its
status. This status becomes the return code for the wait
command. Without job, wait for all currently active child
processes to terminate or stop. The termination status returned
is that of the last process. See the "Jobs" subsection for a
description of the format of job.
whence [-pv] name ...
For each name, indicate how it would be interpreted if used as a
command name. With -v, produce a more verbose report. With -p
do a path search for name, disregarding any use as an alias, a
function, or a reserved word.
Hewlett-Packard Company - 19 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
A word beginning with # causes that word and all the following
characters up to a newline to be ignored.
The first word of each command is replaced by the text of an alias, if
an alias for this word has been defined. An alias name consists of
any number of characters excluding metacharacters, quoting characters,
file expansion characters, parameter and command substitution
characters, and =. The replacement string can contain any valid shell
script, including the metacharacters listed above. The first word of
each command in the replaced text, other than any that are in the
process of being replaced, will be tested for additional aliases. If
the last character of the alias value is a blank, the word following
the alias is also checked for alias substitution. Aliases can be used
to redefine special commands, but cannot be used to redefine the
keywords listed in the "Compound Commands" subsection. Aliases can be
created, listed, and exported with the alias command and can be
removed with the unalias command. Exported aliases remain in effect
for subshells but must be reinitialized for separate invocations of
the shell (see the "Shell Invocation" subsection).
Aliasing is performed when scripts are read, not while they are
executed. Therefore, for it to take effect, an alias must be executed
before the command referring to the alias is read.
Aliases are frequently used as a shorthand for full path names. An
option to the aliasing facility allows the value of the alias to be
automatically set to the full path name of the corresponding command.
These aliases are called tracked aliases. The value of a tracked
alias is defined the first time the identifier is read and becomes
undefined each time the PATH variable is reset. These aliases remain
tracked so that the next reference will redefine the value. Several
tracked aliases are compiled into the shell. The -h option of the set
command converts each command name that is an identifier into a
tracked alias.
The following exported aliases are compiled into the shell but can be
unset or redefined:
autoload='typeset -fu'
command='command '
functions='typeset -f'
history='fc -l'
integer='typeset -i'
nohup='nohup '
r='fc -e -'
stop='kill -STOP'
suspend='kill -STOP $$'
type='whence -v'
Hewlett-Packard Company - 20 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
Tilde Substitution
After alias substitution is performed, each word is checked to see if
it begins with an unquoted tilde (~). If it does, the word up to a /
is checked to see if it matches a user name in the /etc/passwd file.
If a match is found, the ~ and the matched login name are replaced by
the login directory of the matched user. If no match is found, the
original text is left unchanged. A ~ alone or before a / is replaced
by the value of the HOME parameter. A ~ followed by a + or - is
replaced by the value of the parameter PWD and OLDPWD, respectively.
In addition, tilde substitution is attempted when the value of a
parameter assignment begins with a ~.
Command Substitution
The standard output from a command enclosed in parenthesis preceded by
a dollar sign ($(...)) or a pair of grave accents (`...`) can be used
as part or all of a word; trailing newlines are removed. In the
second (archaic) form, the string between the accents is processed for
special quoting characters before the command is executed. See the
"Quoting" subsection. The command substitution $(cat file) can be
replaced by the equivalent but faster $(<<<<file). Command substitution
of most special commands that do not perform input/output redirection
are carried out without creating a separate process.
An arithmetic expression enclosed in double parenthesis preceded by a
dollar sign ($((...))) is replaced by the value of the arithmetic
expression within the double parenthesis. See the "Arithmetic
Evaluation" subsection for a description of arithmetic expressions.
Parameter Substitution
A parameter is an identifier, one or more decimal digits, or one of
the characters !, #, $, *, -, ?, @, and _. A named parameter (a
parameter denoted by an identifier) has a value and zero or more
attributes. Named parameters can be assigned values and attributes
with the typeset special command. Exported parameters pass values and
attributes to the environment.
The shell supports a limited one-dimensional array facility. An
element of an array parameter is referenced by a subscript. A
subscript is denoted by a [, followed by an arithmetic expression,
followed by a ]. See the "Arithmetic Evaluation" subsection. To
assign values to an array, use set -A name value .... The value of
all subscripts must be in the range of 0 through 1023. Arrays need
not be declared. Any reference to a named parameter with a valid
subscript is legal and an array is created if necessary. Referencing
an array parameter without a subscript is equivalent to referencing
the first element.
If the -i integer attribute is set for name, the value is subject to
arithmetic evaluation.
Hewlett-Packard Company - 21 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
Positional parameters, parameters denoted by a number, can be assigned
values with the set special command. Parameter 0 is set from argument
zero when the shell is invoked.
Use the prefix character $ to specify the value of a parameter for
Substitute the value of the parameter, if any. Braces
are required when parameter is followed by a letter,
digit, or underscore that should not be interpreted as
part of its name or when a named parameter is
subscripted. If parameter is one or more digits, it is
a positional parameter. A positional parameter of more
than one digit must be enclosed in braces. The shell
reads all the characters from ${ to the matching } as
part of the same word, even if it contains braces or
If parameter is * or @, all the positional parameters,
starting with 1, are substituted (separated by a field
separator character). See the "Quoting" subsection.
If an array parameter with subscript * or @ is used,
the value for each element is substituted (separated by
a field separator character).
${#parameter} If parameter is * or @, the number of positional
parameters is substituted. Otherwise, the length of
the value of the parameter is substituted.
Substitute the number of elements in the array.
If parameter is set and is nonnull, substitute its
value; otherwise, substitute word.
If parameter is not set or is null, set it to word;
then substitute the value of the parameter. Positional
parameters may not be assigned in this way.
If parameter is set and is nonnull, substitute its
value; otherwise, print word and exit from the shell.
If word is omitted, a standard message is printed.
Hewlett-Packard Company - 22 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
If parameter is set and is nonnull, substitute word;
otherwise, substitute nothing.
If the shell pattern matches the beginning of the value
of parameter, the value of this substitution is the
value of the parameter with the matched portion
deleted; otherwise, the value of this parameter is
substituted. In the former case, the smallest matching
pattern is deleted; in the latter case, the largest
matching pattern is deleted. These characters # or %
should be escaped by a backslash (\) or quotes ('').
If the shell pattern matches the end of the value of
parameter, the value of parameter with the matched part
is deleted; otherwise, substitute the value of
parameter. In the former, the smallest matching
pattern is deleted; in the latter, the largest matching
pattern is deleted. These characters # or % should be
escaped by a backslash (\) or quotes ('').
In the above, word is not evaluated unless it is used as the
substituted string. Thus, in the following example, pwd is executed
only if d is not set or is null:
echo ${d:-$(pwd)}
If the colon (:) is omitted from the above expressions, the shell only
checks to determine whether or not parameter is set.
+ The following parameters are set automatically by the shell:
0 The string used to call the command or script, set from
invocation argument zero.
1, 2, ... The positional parameters.
*, @ All the set positional parameters, separated by a field
separator character. See the "Quoting" subsection.
# The number of set positional parameters in decimal.
- Flags supplied to the shell on invocation or by the set
? The decimal exit status returned by the last executed
Hewlett-Packard Company - 23 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
$ The process number of this shell.
_ Initially, the absolute path name of the shell or
script being executed, as passed in the environment.
Subsequently, it is assigned the last argument of the
previous command. This parameter is not set for
commands which are asynchronous. This parameter is
also used to hold the name of the matching MAIL file
when checking for mail.
! The process number of the last background command
ERRNO The value of errno as set by the most recently failed
system call. This value is system-dependent and is
intended for debugging purposes.
LINENO The line number of the current line within the script
or function being executed.
OLDPWD The previous working directory set by the cd command.
OPTARG The value of the last option argument processed by the
getopts special command.
OPTERR If set to 0, OPTERR will suppress error messages from
the getopts special command. OPTERR is initially set
to 1.
OPTIND The index of the last option argument processed by the
getopts special command.
PPID The process number of the parent of the shell.
PWD The present working directory set by the cd command.
RANDOM Each time this parameter is evaluated, a random
integer, uniformly distributed between 0 and 32767, is
generated. The sequence of random numbers can be
initialized by assigning a numeric value to RANDOM.
REPLY Set by the select compound command, and by the read
special command when no name is supplied.
SECONDS Each time this parameter is referenced, the number of
seconds since shell invocation is returned. If this
parameter is assigned a value, the value returned upon
reference is the value that was assigned plus the
number of seconds since the assignment.
Hewlett-Packard Company - 24 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
+ The following parameters are used by the shell:
CDPATH The search path for the cd command, a list of
directories separated by colons.
COLUMNS If this variable is set, its value is used to define
the width of the edit window for the shell edit modes
and for printing select lists.
EDITOR If the value of this variable ends in emacs, gmacs, or
vi and the VISUAL variable is not set, the
corresponding option is turned on (see the set special
ENV If this parameter is set, parameter substitution is
performed on the value to generate the path name of the
script to be executed when the shell is invoked (see
the "Invocation" subsection). This file is typically
used for alias and function definitions.
FCEDIT The default editor name for the fc command.
FPATH The search path for function definitions, a list of
directories separated by colons. This path is searched
when a function with the -u attribute is referenced and
when a command is not found. If an executable file is
found, then it is read and executed in the current
IFS Internal field separators, normally space, tab, and
newline, that are used to separate command words
resulting from command or parameter substitution and
for separating words with the special command read.
The first character of the IFS parameter is used to
separate arguments for the $* substitution (see the
"Quoting" subsection). If the value of IFS is space,
tab, and newline, or if IFS is unset and it is being
used to separate the results of command or parameter
substitution, any sequence of IFS characters serves to
delimit words; otherwise, each occurrence of a
character in IFS serves to delimit a word. If the
value of IFS is null, no word splitting is done.
HISTFILE If this parameter is set when the shell is invoked, its
value is the path name of the file that is used to
store the command history. The default value is
$HOME/.sh_history. If the user is a superuser and no
HISTFILE is given, then no history file is used. See
the "Command Reentry" subsection and the WARNINGS
Hewlett-Packard Company - 25 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
HISTSIZE If this parameter is set when the shell is invoked, the
number of previously entered commands accessible to
this shell will be greater than or equal to this
number. The default is 128.
HOME The default argument (home directory) for the cd
LANG The locale of your system, which is made up of three
parts: language, territory, and code set. The default
is the C locale. See environ(5).
LC_ALL The overriding value for LANG and the LC_* variables.
See environ(5).
LC_COLLATE The collating sequence to use when sorting names and
when character ranges occur in patterns. See
LC_CTYPE The character classification information to use.
Changing the value of LC_CTYPE after the shell has
started does not affect the lexical processing of shell
commands in the current shell execution environment or
its subshells. See environ(5).
LC_MESSAGES The language in which system messages appear, and the
language that the system expects for user input of yes
and no strings. See environ(5).
LC_MONETARY The currency symbol and monetary value format. See
LC_NUMERIC The numeric format. See environ(5).
LC_TIME The date and time format. See environ(5).
LINES If this variable is set, the value is used to determine
the column length for printing select lists. select
lists print vertically until about two-thirds of LINES
lines are filled.
MAIL If this parameter is set to the name of a mail file and
the MAILPATH parameter is not set, the shell informs
the user of arrival of mail in the specified file.
MAILCHECK How often (in seconds) the shell checks for changes in
the modification time of any of the files specified by
the MAILPATH or MAIL parameters. The default value is
600 seconds. When the time has elapsed, the shell
checks before issuing the next prompt.
Hewlett-Packard Company - 26 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
MAILPATH A list of file names separated by colons. If this
parameter is set, the shell informs the user of any
modifications to the specified files that have occurred
within the last MAILCHECK seconds. Each file name can
be followed by a ? and a message to be printed, in
which case the message will undergo parameter and
command substitution with the parameter $_ defined as
the name of the changed file. The default message is
you have mail in $_.
NLSPATH The search path for message catalogs, a list of
directories separated by colons.
PATH The search path for commands, a list of directories
separated by colons. See the "Execution" subsection.
PS1 The value of this parameter is expanded for parameter
substitution, to define the primary prompt string. The
default value is "$ ". The character ! in the primary
prompt string is replaced by the command number. See
the "Command Reentry" subsection.
PS2 Secondary prompt string for command completion. The
default value is ">>>> ".
PS3 Selection prompt string used within a select loop. If
unset, it defaults to "#? ".
PS4 Execution trace string that precedes each line of an
execution trace. See the set -x special command. If
unset, it defaults to "+ ".
SHELL The path name of the shell is kept in the environment.
When invoked, the shell is restricted if the value of
this variable contains an r in the base name.
TMOUT If set to a value greater than zero, the shell will
terminate if a command is not entered within the
prescribed number of seconds after issuing the PS1
prompt. (Note that the shell can be compiled with a
maximum bound for this value which cannot be exceeded.)
VISUAL Invokes the corresponding option when the value of this
variable ends in emacs, gmacs, or vi. See the set -o
special command.
The shell gives default values to IFS, MAILCHECK, PATH, PS1, PS2, and
TMOUT. On the other hand, MAIL, ENV, HOME, and SHELL are never set
automatically by the shell (although HOME, MAIL, and SHELL are set by
login; see login(1)).
Hewlett-Packard Company - 27 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
Blank Interpretation
After parameter and command substitution, the results of substitution
are scanned for field separator characters (defined in IFS), and split
into distinct arguments when such characters are found. sh retains
explicit null arguments ("" or '') but removes implicit null arguments
(those resulting from parameters that have null values).
File Name Generation
Following substitution, each command word is processed as a pattern
for file name expansion unless expansion has been disabled with the
set -f special command. The form of the patterns is the Pattern
Matching Notation defined in regexp(5). The word is replaced with
sorted file names matching the pattern. If no file name is found that
matches the pattern, the word is left unchanged.
In addition to the notation described in regexp(5), sh recognizes
composite patterns made up of one or more pattern lists separated from
each other with a |. Composite patterns can be formed with one or
more of the following:
?(pattern-list) Matches any one of the given patterns.
*(pattern-list) Matches zero or more occurrences of the given
+(pattern-list) Matches one or more occurrences of the given
@(pattern-list) Matches exactly one of the given patterns.
!(pattern-list) Matches anything, except one of the given
Each of the metacharacters (see the "Definitions" subsection) has a
special meaning to the shell and terminates a word unless quoted. A
character may be quoted (that is, made to stand for itself) by
preceding it with a backslash (\). The pair \newline is ignored; the
current and following lines are concatenated.
All characters enclosed between a pair of apostrophes ('...') are
quoted. An apostrophe cannot appear within apostrophes.
Parameter and command substitution occurs inside quotation marks
("..."). \ quotes the characters \, `, ", and $.
Inside grave accent marks (`...`), \ quotes the characters \, `, and
$. If the grave accents occur within quotation marks, \ also quotes
the character ".
The meanings of $* and $@ are identical when not quoted or when used
as a parameter assignment value or as a file name. However, when used
as a command argument, "$*" is equivalent to "$1d$2d...", whereas "$@"
is equivalent to "$1"d"$2"d... (where d is the first character of
Hewlett-Packard Company - 28 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
The special meaning of keywords or aliases can be removed by quoting
any character of the name. The recognition of function names or
special command names cannot be altered by quoting them.
Arithmetic Evaluation
Integer arithmetic is provided with the special command let.
Evaluations are performed using long integer arithmetic. Constants
take the form base#n or n, where base is a decimal number between two
and thirty-six representing the arithmetic base and n is a number in
that base. If base# is omitted, base 10 is used.
An arithmetic expression uses the same syntax, precedence, and
associativity of expression as the C language. All the integral
operators, other than ++, --, ?:, and , are supported. Variables can
be referenced by name within an arithmetic expression without using
the parameter substitution syntax. When a variable is referenced, its
value is evaluated as an arithmetic expression.
A variable can be typed as an integer with the -i option of the
typeset special command, as in typeset -i[base] name. Arithmetic
evaluation is performed on the value of each assignment to a variable
with the -i attribute. If you do not specify an arithmetic base, the
first assignment to the variable determines the arithmetic base. This
base is used when parameter substitution occurs.
Since many of the arithmetic operators require quoting, an alternative
form of the let command is provided. For any command beginning with
((, all characters until the matching )) are treated as a quoted
expression. More precisely, ((...)) is equivalent to let "...".
When used interactively, the shell prompts with the value of PS1
before reading a command. Whenever a newline is received and further
input is needed to complete a command, the secondary prompt (the value
of PS2) is issued.
Conditional Expressions
A conditional expression is used with the [[ compound command to test
attributes of files and to compare strings. Word splitting and file
name generation are not performed on the words between [[ and ]].
Each expression can be constructed from one or more of the following
unary or binary expressions:
-a file True, if file exists.
-b file True, if file exists and is a block special
-c file True, if file exists and is a character
special file.
-d file True, if file exists and is a directory.
-e file True, if file exists.
Hewlett-Packard Company - 29 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
-f file True, if file exists and is an ordinary file.
-g file True, if file exists and has its setgid bit
-h file True, if file exists and is a symbolic link.
-k file True, if file exists and has its sticky bit
-n string True, if length of string is nonzero.
-o option True, if the set option named option is on.
-p file True, if file exists and is a fifo special
file or a pipe.
-r file True, if file exists and is readable by
current process.
-s file True, if file exists and has a size greater
than zero.
-t fildes True, if file descriptor number fildes is
open and is associated with a terminal
-u file True, if file exists and has its setuid bit
-w file True, if file exists and is writable by the
current process.
-x file True, if file exists and is executable by the
current process. If file exists and is a
directory, then the current process has
permission to search in the directory.
-z string True, if length of string is zero.
-L file True, if file exists and is a symbolic link.
-O file True, if file exists and is owned by the
effective user ID of this process.
-G file True, if file exists and its group matches
the effective group ID of this process.
-S file True, if file exists and is a socket.
file1 -nt file2 True, if file1 exists and is newer than
file1 -ot file2 True, if file1 exists and is older than
file1 -ef file2 True, if file1 and file2 exist and refer to
the same file.
string = pattern True, if string matches pattern.
string != pattern True, if string does not match pattern.
string <<<< string2 True, if string1 comes before string2 based
on the ASCII value of their characters.
string >>>> string2 True, if string1 comes after string2 based on
the ASCII value of their characters.
exp1 -eq exp2 True, if exp1 is equal to exp2.
exp1 -ne exp2 True, if exp1 is not equal to exp2.
exp1 -lt exp2 True, if exp1 is less than exp2.
exp1 -gt exp2 True, if exp1 is greater than exp2.
exp1 -le exp2 True, if exp1 is less than or equal to exp2.
exp1 -ge exp2 True, if exp1 is greater than or equal to
Hewlett-Packard Company - 30 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
A compound expression can be constructed from these primitives by
using any of the following, listed in decreasing order of precedence.
(exp) True, if exp is true. Used to group
!exp True, if exp is false.
exp1 &&&&&&&& exp2 True, if exp1 and exp2 are both true.
exp1 || exp2 True, if either exp1 or exp2 is true.
Before a command is executed, its input and output can be redirected
using a special notation interpreted by the shell. The following can
appear anywhere in a simple-command or may precede or follow a command
and are not passed on to the invoked command. Command and parameter
substitution occurs before word or digit is used, except as noted
below. File name generation occurs only if the pattern matches a
single file and blank interpretation is not performed.
<<<<word Use file word as standard input (file descriptor
>>>>word Use file word as standard output (file descriptor
1). If the file does not exist, it is created.
If the file exists, and the noclobber option is
on, an error occurs; otherwise, the file is
truncated to zero length.
>>>>|word Same as >>>>, except that it overrides the noclobber
>>>>>>>>word Use file word as standard output. If the file
exists, output is appended to it (by first
searching for the end-of-file); otherwise, the
file is created.
<<<<>>>>word Open file word for reading and writing as standard
<<<<<<<<[-]word The shell input is read up to a line that matches
word, or to an end-of-file. No parameter
substitution, command substitution or file name
generation is performed on word. The resulting
document, called a here-document, becomes the
standard input. If any character of word is
quoted, no interpretation is placed upon the
characters of the document. Otherwise, parameter
and command substitution occurs, \newline is
ignored, and \ must be used to quote the
characters \, $, `, and the first character of
word. If - is appended to <<<<<<<<, all leading tabs
are stripped from word and from the document.
Hewlett-Packard Company - 31 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
<<<<&&&&digit The standard input is duplicated from file
descriptor digit (see dup(2)).
>>>>&&&&digit The standard output is duplicated to file
descriptor digit (see dup(2)).
<<<<&&&&- The standard input is closed.
>>>>&&&&- The standard output is closed.
<<<<&&&&p The input from the coprocess is moved to standard
>>>>&&&&p The output to the coprocess is moved to standard
If any of the above redirections is preceded by a digit (0 to 9), the
file descriptor used is the one specified by the digit, instead of the
default 0 (standard input) or 1 (standard output). For example:
means open file descriptor 2 for writing as a duplicate of file
descriptor 1. Output directed to file descriptor 2 is written in the
same location as output to file descriptor 1.
Order is significant in redirection. The shell evaluates each
redirection in terms of the (file descriptor, file) assignment at the
time of evaluation. For example:
1>>>>fname 2>>>>&&&&1
first assigns file descriptor 1 to file fname. It then assigns file
descriptor 2 to the file assigned to file descriptor 1 (that is,
If the order of redirection is reversed, as in
2>>>>&&&&1 1>>>>fname
file descriptor 2 is assigned to the file assigned to file descriptor
1 (probably the terminal) and then file descriptor 1 is assigned to
file fname.
By using the redirection operators above, the input and output of a
coprocess may be moved to a numbered file descriptor, allowing other
commands to write to them and read from them. If the input of the
current coprocess is moved to a numbered file descriptor, another
coprocess may be started.
Hewlett-Packard Company - 32 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
If a command is followed by &&&& and job control is inactive, the default
standard input for the command is the empty file /dev/null.
Otherwise, the environment for the execution of a command contains the
file descriptors of the invoking shell as modified by input/output
The environment (see environ(5)) is a list of name-value pairs passed
to an executed program much like a normal argument list. The names
must be identifiers and the values are character strings. The shell
interacts with the environment in several ways. When invoked, the
shell scans the environment and creates a parameter for each name
found, gives it the corresponding value and marks it export. Executed
commands inherit the environment. If the user modifies the values of
these parameters or creates new ones by using the export or typeset -x
special commands, the values become part of the environment. The
environment seen by any executed command is thus composed of any
name-value pairs originally inherited by the shell, whose values may
be modified by the current shell, plus any additions which must be
noted in export or typeset -x commands.
The environment for any simple command or function can be augmented by
prefixing it with one or more parameter assignments. A parameter
assignment argument takes the form identifier=value. For example,
both the following
TERM=450 cmd args
(export TERM; TERM=450; cmd args)
are equivalent (as far as the execution of cmd is concerned, except
for the special commands that are preceded by a percent sign (%).
If the -k option is set, all parameter assignment arguments are placed
in the environment, even if they occur after the command name. The
following echo statement prints a=b c. After the -k option is set,
the second echo statement prints only c:
echo a=b c -> a=b c
set -k
echo a=b c -> c
This feature is intended for use with scripts written for early
versions of the shell and its use in new scripts is strongly
discouraged. It is likely to disappear someday.
The function command (described in the "Compound Commands" subsection)
defines shell functions. Shell functions are read and stored
internally. Alias names are resolved when the function is read.
Functions are executed like commands, with the arguments passed as
positional parameters. (See the "Execution" subsection.)
Hewlett-Packard Company - 33 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
Functions execute in the same process as the caller and share all
files and current working directory with the caller. Traps defined by
the caller remain in effect within the function until another trap
command is executed. Traps set within a function remain in effect
after the function returns. Ordinarily, variables are shared between
the calling program and the function. However, the typeset special
command can be used within a function to define local variables whose
scope includes the current function and all functions it calls.
The return special command is used to return from function calls.
Errors within functions return control to the caller.
Function identifiers can be listed with the +f option of the typeset
special command. Function identifiers and the associated text of the
functions can be listed with the -f option. Functions can be
undefined with the -f option of the unset special command.
Ordinarily, functions are unset when the shell executes a shell
script. The -xf option of the typeset command allows a function to be
exported to scripts that are executed without reinvoking the shell.
Functions that must be defined across separate invocations of the
shell should be placed in the ENV file.
If the monitor option of the set command is turned on, an interactive
shell associates a job with each pipeline. It keeps a table of
current jobs, printed by the jobs command, and assigns them small
integer numbers. When a job is started asynchronously with &&&&, the
shell prints a line that looks like:
[1] 1234
indicating that job number 1 was started asynchronously and had one
(top-level) process whose process ID was 1234.
If you are running a job and wish to do something else, you can type
the suspend character (the susp character defined with stty; see
stty(1)) to send a SIGSTOP signal to the current job. The shell then
indicates that the job has been Stopped, and prints another prompt.
Then you can manipulate the state of this job by putting it in the
background with the bg command, running other commands, and eventually
returning the job to the foreground with the fg command. A suspend
takes effect immediately and resembles an interrupt, since pending
output and unread input are discarded when the suspend is entered.
A job running in the background stops if it tries to read from the
terminal. Background jobs normally are allowed to produce output, but
can be disabled with the stty tostop command. If the user sets this
terminal option, background jobs stop when trying to produce output.
Hewlett-Packard Company - 34 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
There are several ways to refer to jobs in the shell. A job can be
referred to by the process ID of any process in the job or by one of
the following:
%number The job with the given number.
%string Any job whose command line begins with
%?string Any job whose command line contains string.
%% Current job.
%+ Equivalent to %%.
%- Previous job.
The shell learns immediately when a process changes state. It informs
the user when a job is blocked and prevented from further progress,
but only just before it prints a prompt.
When the monitor mode is on, each background job that completes
triggers any trap set for SIGCHLD.
If you try to exit from shell while jobs are stopped, you are warned
with the message You have stopped jobs. You can use the jobs command
to identify them. If you immediately try to exit again, the shell
will not warn you a second time, and the stopped jobs will be
If you try to leave the shell while jobs are running, you are not
warned. The shell exits silently and sets the parent of the running
jobs to the init process (number 1).
The SIGINT and SIGQUIT signals for an invoked command are ignored if
the command is followed by &&&& and the monitor option is off.
Otherwise, signals have the values inherited by the shell from its
parent, with the exception of signal SIGSEGV (but see also the trap
special command).
Substitutions are made each time a command is executed. sh checks the
command name to determine whether it matches a special command. If it
does, it is executed within the current shell process.
Next, sh checks the command name to determine whether it matches one
of the user-defined functions. If it does, sh saves the positional
parameters, then sets them to the arguments of the function call. The
positional parameter 0 is unchanged. When the function completes or
issues a return, sh restores the positional parameter list. The value
of a function is the value of the last command executed. A function
is executed in the current shell process.
If a command name is not a user-defined function or a special command,
sh creates a process and attempts to execute the command using an
Hewlett-Packard Company - 35 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
exec*() system call (see exec(2)).
The shell parameter PATH defines the search path for the directory
containing the command. Alternative directory names are separated by
a colon (:). The default path is /usr/bin: (specifying /usr/bin, and
the current directory, in that order). Note that the current
directory is specified by a null path name, which can appear
immediately after the equal sign, between colon delimiters, or at the
end of the path list. The search path is not used if the command name
contains a /. Otherwise, each directory in the path is searched for
an executable file. If the file has execute permissions but is not a
directory or an executable object code file, it is assumed to be a
script file, which is a file of data for an interpreter. If the first
two characters of the script file are #!, exec*() expects an
interpreter path name to follow. exec*() then attempts to execute the
specified interpreter as a separate process to read the entire script
file. If a call to exec*() fails, sh is spawned to interpret the
script file. All nonexported aliases, functions, and named parameters
are removed in this case. If the shell command file does not have
read permission, or if the setuid and/or setgid bits are set on the
file, the shell executes an agent to set up the permissions and
execute the shell with the shell command file passed down as an open
file. A parenthesized command is also executed in a subshell without
removing nonexported quantities.
Command Reentry
The text of the last HISTSIZE (default 128) commands entered from a
terminal device is saved in a history file. The file
$HOME/.sh_history is used if the HISTFILE variable is not set or
writable. A shell can access the commands of all interactive shells
that use the same named HISTFILE. The special command fc is used to
list or edit a portion of this file. The portion of the file to be
edited or listed can be selected by number or by giving the first
character or characters of the command. A single command or range of
commands can be specified. If you do not specify an editor program as
an argument to fc, the value of the parameter FCEDIT is used. If
FCEDIT is not defined, /usr/bin/ed is used. The edited command is
printed and reexecuted upon leaving the editor. The editor name - is
used to skip the editing phase and to reexecute the command. In this
case, a substitution parameter of the form old=new can be used to
modify the command before execution. For example, if r is aliased to
fc -e -, typing r bad=good c reexecutes the most recent command that
starts with the letter c and replaces the first occurrence of the
string bad with the string good.
The history file will be trimmed when all of the following conditions
Its size is greater than four kilobytes.
Hewlett-Packard Company - 36 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
The number of commands in it is more than HISTSIZE.
The file has not been modified in the last ten minutes.
The user has write permission for the directory in which the
history file resides.
If any one of the above conditions does not occur, the history file
will not be trimmed. When the history file is trimmed, the latest
HISTSIZE commands will be available in the history file.
Command Line Editing
Normally, each command line typed at a terminal device is followed by
a newline or return. If one of the emacs, gmacs, vi, or viraw,
options is set, you can edit the command line. An editing option is
automatically selected each time the VISUAL or EDITOR variable is
assigned a value ending in one of these option names.
The editing features require that the user's terminal accept return
without line feed and that a space (" ") must overwrite the current
character on the screen. ADM terminal users should set the
"space - advance" switch to "space". Hewlett-Packard terminal users
should set the straps to "bcGHxZ etX".
The editing modes enable the user to look through a window at the
current line. The default window width is 80, unless the value of
COLUMNS is defined. If the line is longer than the window width minus
two, a mark displayed at the end of the window notifies the user. The
mark is one of:
>>>> The line extends to the right.
<<<< The line extends to the left.
* The line extends to both sides of the window.
As the cursor moves and reaches the window boundaries, the window is
centered about the cursor.
The search commands in each edit mode provide access to the history
file. Only strings are matched, not patterns, although a leading ^ in
the string restricts the match to begin at the first character in the
emacs Editing Mode
This mode is invoked by either the emacs or gmacs option. Their sole
difference is their handling of ^T. To edit, the user moves the
cursor to the point needing correction and inserts or deletes
characters or words. All editing commands are control characters or
escape sequences. The notation for control characters is caret (^)
followed by a character. For example, ^F is the notation for
Control-F. This is entered by holding down the Ctrl (control) key and
pressing f. The shift key is not pressed. The notation ^? indicates
Hewlett-Packard Company - 37 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
the delete (DEL) key.
The notation for escape sequences is M- followed by a character. For
example, M-f (pronounced meta f) is entered by pressing the escape key
(ESC) followed by pressing f. M-F is the notation for escape followed
by shift (capital) F.
All edit commands operate from any place on the line (not only at the
beginning). Neither the return (^M) nor the newline (^J) key is
entered after edit commands, except when noted.
^F Move cursor forward (right) one character.
M-f Move cursor forward one word. (The editor's idea
of a word is a string of characters consisting of
only letters, digits and underscores.)
^B Move cursor backward (left) one character.
M-b Move cursor backward one word.
^A Move cursor to start of line.
^E Move cursor to end of line.
^]char Move cursor forward to character char on current
M-^]char Move cursor backward to character char on current
^X^X Interchange the cursor and mark.
erase Delete previous character. (User-defined erase
character as defined by the stty command, usually
^H or #.)
^D Delete current character.
eof Terminate the shell if the current line is null.
(User-defined end-of-file character as defined by
the stty command, usually ^D.)
M-d Delete current word.
M-^H Delete previous word. (meta-backspace)
M-h Delete previous word.
M-^? Delete previous word. (meta-delete) If your
interrupt character is ^? (DEL, the default), this
command will not work.
^T In emacs mode, transpose current character with
next character. In gmacs mode, transpose two
previous characters.
^C Capitalize current character.
M-c Capitalize current word.
M-l Change the current word to lowercase.
^K Delete from the cursor to the end of the line. If
preceded by a numerical parameter whose value is
less that the current cursor position, then delete
from the given position up to the cursor. If
preceded by a numerical parameter whose value is
greater than the current cursor position, then
delete from the cursor up to the given position.
Hewlett-Packard Company - 38 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
^W Kill from the cursor to the mark.
M-p Push the region from the cursor to the mark on the
kill Kill the entire current line. If two kill
characters are entered in succession, all
subsequent consecutive kill characters cause a
line feed (useful when using paper terminals).
(User-defined kill character as defined by the
stty command, usually ^X or @.)
^Y Restore last item removed from line. (Yank item
back to the line.)
^L Line feed and print current line.
^@ Set mark. (null character)
M- Set mark. (meta-space)
^J Execute the current line. (newline)
^M Execute the current line. (return)
^P Fetch previous command. Each time ^P is entered,
the previous command in the history list is
^N Fetch next command. Each time ^N is entered the
next command in the history list is accessed.
M-<<<< Fetch the least recent (oldest) history line.
M->>>> Fetch the most recent (youngest) history line.
^Rstring Reverse search history for a previous command line
containing string. If a parameter of zero is
given, the search is forward. string is
terminated by a return or newline. If string is
preceded by a ^, the matched line must begin with
string. If string is omitted, the next command
line containing the most recent string is
accessed. In this case, a parameter of zero
reverses the direction of the search.
^O Execute the current line and fetch the next line
relative to current line from the history file.
M-digits Define a numeric parameter. The digits are taken
as a parameter to the next command. The commands
that accept a parameter are erase, ^B, ^C, ^D, ^F,
^K, ^N, ^P, ^R, ^], M-^H, M-., M-_, M-b, M-c, M-d,
M-f, M-h, and M-l.
M-letter Your alias list is searched for an alias by the
name _letter (underscore-letter). If an alias of
this name is defined, its value is inserted on the
input queue. This letter must not be one of the
above metafunctions.
M-. The last word of the previous command is inserted
on the line. If preceded by a numeric parameter,
the value of this parameter determines which word
to insert rather than the last word.
M-_ Same as M-..
M-* Attempt file name generation on the current word.
Hewlett-Packard Company - 39 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
M-^[ File name completion. (meta-escape.) Replaces the
current word with the longest common prefix of all
file names matching the current word with an
asterisk appended. If the match is unique, a / is
appended if the file is a directory and a space is
appended if the file is not a directory.
M-= List files matching current word pattern as if an
asterisk were appended.
^U Multiply parameter of next command by 4.
\ Escape next character. Editing characters and
your erase, kill, and interrupt characters may be
entered in a command line or in a search string,
if preceded by a \. The \ removes the next
character's editing features (if any).
^V Display version of the shell.
M-# Insert a # at the beginning of the line and
execute it. This causes a comment to be inserted
in the history file.
vi Editing Mode
The editor starts in insert mode until an escape (ESC) is received.
This puts you in control mode in which you can move the cursor and
perform editing commands. A return in either mode sends the line.
Most control commands accept an optional repeat count prior to the
In vi mode on most systems, canonical processing is initially enabled
and the command is echoed again if the speed is 1200 baud or greater
and contains any control characters, or if less than one second has
elapsed since the prompt was printed. The escape (ESC) character
terminates canonical processing for the remainder of the command and
you can then modify the command line. This scheme has the advantages
of canonical processing with the typeahead echoing of raw mode.
Setting the viraw option always disables canonical processing on the
terminal. This mode is implicit for systems that do not support two
alternate end-of-line delimiters, and may be helpful for certain
Insert Edit Commands
By default, the editor is in insert mode.
erase Delete previous inserted character. The erase
character is user-definable with the stty command,
usually set to ^H. The system default is #.
kill Delete all current inserted characters. The kill
character is user-definable with the stty command,
usually set to ^X or ^U. The system default is @.
\ Escape the next erase or kill character.
Hewlett-Packard Company - 40 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
^D Terminate the shell.
^V Escape next character. Editing characters and
erase or kill characters may be entered in a
command line or in a search string if preceded by
a ^V, which removes the next character's editing
features (if any).
^W Delete the previous blank-separated word.
Motion Edit Commands
These commands move the cursor. The use of count causes a repetition
of the command the cited number of times.
[count]l Cursor forward (right) one character.
[count]w Cursor forward one alphanumeric word.
[count]W Cursor forward to the beginning of the next word
that follows a blank.
[count]e Cursor forward to the end of the word.
[count]E Cursor forward to end of the current blank-
delimited word.
[count]h Cursor backward (left) one character.
[count]b Cursor backward one word.
[count]B Cursor backward to preceding blank-separated word.
[count]| Cursor to column count. Default is 1.
[count]fc Find the next character c in the current line.
[count]Fc Find the previous character c in the current line.
[count]tc Equivalent to fc followed by h.
[count]Tc Equivalent to Fc followed by l.
[count]; Repeat the last single-character find command, f,
F, t, or T.
[count], Reverses the last single character find command.
0 Cursor to start of line.
^ Cursor to first nonblank character in line.
$ Cursor to end of line.
History Search Commands
These commands access your command history file.
[count]k Fetch previous command. Each time k is entered,
the next earlier command in the history list is
[count]- Equivalent to k.
[count]j Fetch next command. Each time j is entered, the
next later command in the history list is
[count]+ Equivalent to j.
[count]G The command number count is fetched. The default
is the first command in the history list.
/string Search backward through history for a previous
command containing string. string is terminated
by a return or newline. If string is preceded by
a ^, the matched line must begin with string. If
Hewlett-Packard Company - 41 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
string is null, the previous string is used.
?string Same as /, but search in the forward direction.
n Search for next match of the last pattern to the /
or ? commands.
N Search for next match of the last pattern to / or
?, but in reverse direction.
Text Modification Edit Commands
These commands will modify the line.
a Enter insert mode after the current character.
A Append text to the end of the line. Equivalent to
c[count]motion Move cursor forward to the character position
specified by motion, deleting all characters
between the original cursor position and the new
position, and enter insert mode. If motion is c,
the entire line is deleted.
C Delete from the current character through the end
of line and enter insert mode. Equivalent to c$.
S Equivalent to cc.
d[count]motion Move cursor to the character position specified by
motion, deleting all characters between the
original cursor position and the new position. If
motion is d, the entire line will be deleted.
D Delete from the current character through the end
of line. Equivalent to d$.
i Enter insert mode before the current character.
I Enter insert mode before the beginning of the
line. Equivalent to the two-character sequence
[count]P Insert the previous text modification before the
[count]p Insert the previous text modification after the
R Enter insert mode and replace characters on the
screen with characters you type, overlay fashion.
[count]rc Replace the current character with c.
[count]x Delete the current character.
[count]X Delete the preceding character.
[count]. Repeat the previous text modification command.
~ Invert the case of the current character and
advance the cursor.
[count]_ Append the count word of the previous command at
the current cursor location and enter insert mode
at the end of the appended text. The last word is
used if count is omitted.
* Append an * to the current word and attempt file
name generation. If no match is found, ring the
Hewlett-Packard Company - 42 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
bell. If a match is found, replace the word with
the matching string of file names and enter insert
\ Attempt file name completion on the current word.
Replace the current word with the longest common
prefix of all file names matching the current word
with an asterisk appended. If the match is
unique, append a / if the file is a directory or
append a space if the file is not a directory.
Other Edit Commands
y[count]motion Yank current character through character that
motion would move the cursor to and put them into
the delete buffer. The text and cursor are
Y Yank from current position to end of line.
Equivalent to y$.
u Undo the last text-modifying command.
U Undo all the text-modifying commands performed on
the line.
[count]v Execute the command fc -e ${VISUAL:-${EDITOR:-vi}}
count in the input buffer. If count is omitted,
the current line is used. This executes an editor
with the current line as the input "file". When
you exit from the editor, the result is executed.
^L Line feed and print current line.
^J Execute the current line, regardless of mode.
^M Execute the current line, regardless of mode.
# Insert a # at the beginning of the current line
and after each embedded newline, and execute the
line. Useful for inserting the current command
line in the history list without executing it.
= List the file names that match the current word if
an asterisk were appended to it.
@letter Search your alias list for an alias with the name
_letter (underscore letter). If an alias of this
name is defined, its value is executed as a
command sequence on the current line. This
provides a simple macro capability.
Environment Variables
LC_COLLATE determines the collating sequence used in evaluating
pattern matching notation for file name generation. If it is not
defined or is empty, it defaults to the value of LANG.
Hewlett-Packard Company - 43 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
LC_CTYPE determines the classification of characters as letters, and
the characters matched by character class expressions in pattern
matching notation. If it is not defined or is empty, it defaults to
the value of LANG.
If LANG is not defined or is empty, it defaults to C (see lang(5)).
If any internationalization variable contains an invalid value, they
all default to C (see environ(5)).
International Code Set Support
Single- and multibyte character code sets are supported.
Errors detected by the shell, such as syntax errors, cause the shell
to return a nonzero exit status. Otherwise, the shell returns the
exit status of the last command executed. See also the exit special
command. If the shell is being used noninteractively, the execution
of the shell file is abandoned. Runtime errors detected by the shell
are reported by printing the command or function name and the error
condition. If the line number on which the error occurred is greater
than one, the line number is also printed in brackets ([]) after the
command or function name.
Some file descriptors are used internally by the POSIX shell. For
HP-UX releases 10.10 and beyond, file descriptors 24 through 30 are
reserved. HP-UX releases 10.00 and 10.01 reserve descriptors 54
through 60. Applications using these and forking a subshell should
not depend upon them surviving in the subshell or its descendants.
If a command that is a tracked alias is executed, and a command with
the same name is installed in a directory in the search path before
the directory where the original command was found, the shell will
continue to load and execute the original command. Use the -t option
of the alias command to correct this situation.
If you move the current directory or one above it, pwd may not give
the correct response. Use the cd command with a full path name to
correct this situation.
Some very old shell scripts use a caret (^) as a synonym for the pipe
character (|). sh does not recognize the caret as a pipe character.
If a command is piped into a shell command, all variables set in the
shell command are lost when the command completes.
Using the fc built-in command within a compound command will cause the
entire command to disappear from the history file.
Hewlett-Packard Company - 44 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
The dot (.) special command, as in . file, reads the entire file
before any commands are executed. Therefore, alias and unalias
commands in the file will not apply to any functions defined in the
Traps are not processed while the shell is waiting for a foreground
job. Thus, a trap on SIGCHLD is not executed until the foreground job
The export special command does not handle arrays properly. Only the
first element of an array is exported to the environment.
Background processes started from a noninteractive shell cannot be
accessed with job control commands.
The value of the IFS variable in the user's environment affects the
behavior of scripts.
Collating Order
In an international environment, character ordering is determined by
the value of LC_COLLATE, rather than by the binary ordering of
character values in the machine collating sequence. This brings with
it certain attendant dangers, particularly when using range
expressions in file name generation patterns. For example, the
rm [a-z]*
might be expected to match all file names beginning with a lowercase
alphabetic character. However, if dictionary ordering is specified by
LC_COLLATE, it would also match file names beginning with an uppercase
character (as well as those beginning with accented letters).
Conversely, it would fail to match letters collated after z in
languages such as Danish or Norwegian.
The correct (and safe) way to match specific character classes in an
international environment is to use a pattern (see regexp(5)) of the
rm [[:lower:]]*
This uses LC_CTYPE to determine character classes and works
predictably for all supported languages and codesets. For shell
scripts produced on noninternationalized systems (or without
consideration for the above dangers), it is recommended that they be
executed in a non-NLS environment. This requires that LANG,
LC_COLLATE, and so on, be set to C or not set at all.
The history file does not support mixing of locales in the same file.
For users of multiple locales, you can assign a unique history file
for each locale by setting HISTFILE as:
Hewlett-Packard Company - 45 - HP-UX Release 11i: November 2000
sh-posix(1) sh-posix(1)
sh was developed by AT&T, OSF, and HP.
$HOME/.profile Read to set up user's custom environment
/etc/passwd To find home directories
/etc/profile Read to set up system environment
/etc/suid_profile Security profile
/var/tmp/sh* For here-documents if /var/tmp is
/tmp/sh* For here-documents if /var/tmp is not
/usr/bin/sh Shell executable program location
cat(1), cd(1), command(1), echo(1), ed(1), env(1), getopts(1),
kill(1), ln(1), login(1), newgrp(1), printf(1), pwd(1), read(1),
stty(1), test(1), time(1), umask(1), vi(1), dup(2), exec(2), fork(2),
pipe(2), stty(2), ulimit(2), umask(2), wait(2), rand(3C), a.out(4),
profile(4), environ(5), lang(5), regexp(5), signal(5).
sh: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
break: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
case: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
continue: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
eval: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
exec: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
exit: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
export: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
for: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
if: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
read: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
return: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
set: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
shift: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
time: SVID2, SVID3, XPG2, XPG3, XPG4
trap: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
unset: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
until: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
while: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
Hewlett-Packard Company - 46 - HP-UX Release 11i: November 2000


text:
Welcome to BodySafe Products
home of the tow Bar-Guard
The Bar-Guard
Towbar Injury Prevention Unit
Have you ever hit your leg on a towbar?
The Bar-Guard
has been designed to reduce injury and to minimize damage from protruding towbar tongues,
the only unprotected part of a vehicle.
Save money
, protect your no claim bonus from accidental blind spot touch parking, (if you are covered by insurance -
You may not be
Refer to our
insurance information
Did you know?
The Bar-Guard
may protect you from litigatian and fines of up to $500.
Refer to our 1999 National
Regulations page
The Bar-Guard Order Form
Speed Awareness Indicator
No more speeding fines!
Revolutionary new way of checking your speed.
The Speed Saver, your 10 kph
(eg. set at 60kmph and use for 50kmph as well)
- Fits to all clock faced speedos and speedo covers in seconds, regardless of angle, (directly in line with with driver).
- Preset to any speed limit in seconds.
- Less time needed to focus to check speed.
- No more continually reading numbers, keep your speedo needle within a set range.
- No more continually adjusting cruise controls.
- Helps with adjusting to new speed limits.
- Instant speedo needle check in all driving conditions.
- Back-lit for easy night reading.
Don't let your speedo needle get away from you!
The Speed Saver Order Form
BodySafe Products Surveys
Please take the time to complete our Towbar Safety survey
The Towbar Safety Survey
For users of a Speed Saver, please feel free to complete our Fact Finding Revue
The Fact Finding Revue
Survey results so far.
Other Information
View the articles in which our products appear.
View testimonials sent to us by satisified customers.
View some letters sent to us in regard to towbar laws in Australia.
With your safety in mind...
Bob Dunn
Bob Dunn, inventor of both the Bar-Guard
and the Speed Awareness Indicator
Contact Details
Bodysafe Products
1066 Dunolly Rd.
Victoria 3472
+061 03 5469 7202

subset: commoncrawl


text:
[Home] [Site map] [Updates] [Projects]
These are Bible verses read in my morning `quiet time' on the second coming of the Lord Jesus Christ, being one of my New Year's resolutions in 2007. This is today, 14 January, 2008 completed! Tomorrow I will start my next morning `quiet time' study project, Jesus is Jehovah!
[Introduction; Fact; Predicted in OT; Called; Nature; Purpose; Events; Signs; Types; Time; Response; Conclusion; References]