GNU parallel

GNU parallel is a command-line driven utility for Linux and other Unix-like operating systems which allows the user to execute shell scripts or commands in parallel. GNU parallel is free software, written by Ole Tange in Perl. It is available under the terms of GPLv3.
Usage.
The most common usage is to replace the shell loop, for example
while read x; do 
 do_something "$x"
done < list | process_output
to the form of
< list parallel do_something | process_output
where the file codice_1 contains arguments for codice_2 and where codice_3 may be empty.
Scripts using parallel are often easier to read than scripts using pexec.
The program parallel features also
By default, parallel runs as many jobs in parallel as there are CPU cores.
Examples.
find . -name "*.foo" | parallel grep bar
The above is the parallel equivalent to:
find . -name "*.foo" -exec grep bar {} +
This searches in all files in the current directory and its subdirectories whose name end in codice_4 for occurrences of the string codice_5. The parallel command will work as expected unless a file name contains a newline. In order to avoid this limitation one may use:
find . -name "*.foo" -print0 | parallel -0 grep bar
The above command uses the null character to delimit file names.
find . -name "*.foo" | parallel -X mv {} /tmp/trash
The above command expands codice_6 with as many arguments as the command line length permits, distributing them evenly among parallel jobs if required. This can lower process overhead for short-lived commands that take less time to finish than they do to launch.
find . -maxdepth 1 -type f -name "*.ogg" | parallel -X -r cp -v -p {} /home/media
The command above does the same as:
cp -v -p *.ogg /home/media
However, the former command which uses codice_7/codice_8/codice_9 is more resource efficient and will not halt with an error if the expansion of *.ogg is too large for the shell.