text: /* Utilities to execute a program in a subprocess (possibly linked by pipes
     with other subprocesses), and wait for it.  Shared logic.
     Copyright (C) 1996-2017 Free Software Foundation, Inc.
  
  This file is part of the libiberty library.
  Libiberty is free software; you can redistribute it and/or
  modify it under the terms of the GNU Library General Public
  License as published by the Free Software Foundation; either
  version 2 of the License, or (at your option) any later version.
  
  Libiberty is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Library General Public License for more details.
  
  You should have received a copy of the GNU Library General Public
  License along with libiberty; see the file COPYING.LIB.  If not,
  write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
  Boston, MA 02110-1301, USA.  */
  
  #ifndef PEX_COMMON_H
  #define PEX_COMMON_H
  
  #include "config.h"
  #include "libiberty.h"
  #include <stdio.h>
  
  /* pid_t is may defined by config.h or sys/types.h needs to be
     included.  */
  #if !defined(pid_t) && defined(HAVE_SYS_TYPES_H)
  #include <sys/types.h>
  #endif
  
  #define install_error_msg "installation problem, cannot exec `%s'"
  
  /* stdin file number.  */
  #define STDIN_FILE_NO 0
  
  /* stdout file number.  */
  #define STDOUT_FILE_NO 1
  
  /* stderr file number.  */
  #define STDERR_FILE_NO 2
  
  /* value of `pipe': port index for reading.  */
  #define READ_PORT 0
  
  /* value of `pipe': port index for writing.  */
  #define WRITE_PORT 1
  
  /* The structure used by pex_init and friends.  */
  
  struct pex_obj
  {
    /* Flags.  */
    int flags;
    /* Name of calling program, for error messages.  */
    const char *pname;
    /* Base name to use for temporary files.  */
    const char *tempbase;
    /* Pipe to use as stdin for next process.  */
    int next_input;
    /* File name to use as stdin for next process.  */
    char *next_input_name;
    /* Whether next_input_name was allocated using malloc.  */
    int next_input_name_allocated;
    /* If not -1, stderr pipe from the last process.  */
    int stderr_pipe;
    /* Number of child processes.  */
    int count;
    /* PIDs of child processes; array allocated using malloc.  */
    pid_t *children;
    /* Exit statuses of child processes; array allocated using malloc.  */
    int *status;
    /* Time used by child processes; array allocated using malloc.  */
    struct pex_time *time;
    /* Number of children we have already waited for.  */
    int number_waited;
    /* FILE created by pex_input_file.  */
    FILE *input_file;
    /* FILE created by pex_read_output.  */
    FILE *read_output;
    /* FILE created by pex_read_err.  */
    FILE *read_err;
    /* Number of temporary files to remove.  */
    int remove_count;
    /* List of temporary files to remove; array allocated using malloc
       of strings allocated using malloc.  */
    char **remove;
    /* Pointers to system dependent functions.  */
    const struct pex_funcs *funcs;
    /* For use by system dependent code.  */
    void *sysdep;
  };
  
  /* Functions passed to pex_run_common.  */
  
  struct pex_funcs
  {
    /* Open file NAME for reading.  If BINARY is non-zero, open in
       binary mode.  Return >= 0 on success, -1 on error.  */
    int (*open_read) (struct pex_obj *, const char */* name */, int /* binary */);
    /* Open file NAME for writing.  If BINARY is non-zero, open in
       binary mode.  Return >= 0 on success, -1 on error.  */
    int (*open_write) (struct pex_obj *, const char */* name */,
                       int /* binary */, int /* append */);
    /* Execute a child process.  FLAGS, EXECUTABLE, ARGV, ERR are from
       pex_run.  IN, OUT, ERRDES, TOCLOSE are all descriptors, from
       open_read, open_write, or pipe, or they are one of STDIN_FILE_NO,
       STDOUT_FILE_NO or STDERR_FILE_NO; if IN, OUT, and ERRDES are not
       STD*_FILE_NO, they should be closed.  If the descriptor TOCLOSE
       is not -1, and the system supports pipes, TOCLOSE should be
       closed in the child process.  The function should handle the
       PEX_STDERR_TO_STDOUT flag.  Return >= 0 on success, or -1 on
       error and set *ERRMSG and *ERR.  */
    pid_t (*exec_child) (struct pex_obj *, int /* flags */,
                        const char */* executable */, char * const * /* argv */,
                        char * const * /* env */,
                        int /* in */, int /* out */, int /* errdes */,
  		      int /* toclose */, const char **/* errmsg */,
  		      int */* err */);
    /* Close a descriptor.  Return 0 on success, -1 on error.  */
    int (*close) (struct pex_obj *, int);
    /* Wait for a child to complete, returning exit status in *STATUS
       and time in *TIME (if it is not null).  CHILD is from fork.  DONE
       is 1 if this is called via pex_free.  ERRMSG and ERR are as in
       fork.  Return 0 on success, -1 on error.  */
    pid_t (*wait) (struct pex_obj *, pid_t /* child */, int * /* status */,
                 struct pex_time * /* time */, int /* done */,
                 const char ** /* errmsg */, int * /* err */);
    /* Create a pipe (only called if PEX_USE_PIPES is set) storing two
       descriptors in P[0] and P[1].  If BINARY is non-zero, open in
       binary mode.  Return 0 on success, -1 on error.  */
    int (*pipe) (struct pex_obj *, int * /* p */, int /* binary */);
    /* Get a FILE pointer to read from a file descriptor (only called if
       PEX_USE_PIPES is set).  If BINARY is non-zero, open in binary
       mode.  Return pointer on success, NULL on error.  */
    FILE * (*fdopenr) (struct pex_obj *, int /* fd */, int /* binary */);
    /* Get a FILE pointer to write to the file descriptor FD (only
       called if PEX_USE_PIPES is set).  If BINARY is non-zero, open in
       binary mode.  Arrange for FD not to be inherited by the child
       processes.  Return pointer on success, NULL on error.  */
    FILE * (*fdopenw) (struct pex_obj *, int /* fd */, int /* binary */);
    /* Free any system dependent data associated with OBJ.  May be
       NULL if there is nothing to do.  */
    void (*cleanup) (struct pex_obj *);
  };
  
  extern struct pex_obj *pex_init_common (int, const char *, const char *,
  					const struct pex_funcs *);
  
  #endif
  