| /* Utilities to execute a program in a subprocess (possibly linked by pipes |
| with other subprocesses), and wait for it. Generic Unix version |
| (also used for UWIN and VMS). |
| Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2003 |
| 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., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include "pex-common.h" |
| |
| #include <stdio.h> |
| #include <errno.h> |
| #ifdef NEED_DECLARATION_ERRNO |
| extern int errno; |
| #endif |
| #ifdef HAVE_STRING_H |
| #include <string.h> |
| #endif |
| #ifdef HAVE_UNISTD_H |
| #include <unistd.h> |
| #endif |
| #ifdef HAVE_STDLIB_H |
| #include <stdlib.h> |
| #endif |
| #ifdef HAVE_SYS_WAIT_H |
| #include <sys/wait.h> |
| #endif |
| |
| #ifndef HAVE_WAITPID |
| #define waitpid(pid, status, flags) wait(status) |
| #endif |
| |
| extern int execv (); |
| extern int execvp (); |
| |
| int |
| pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags) |
| const char *program; |
| char * const *argv; |
| const char *this_pname; |
| const char *temp_base ATTRIBUTE_UNUSED; |
| char **errmsg_fmt, **errmsg_arg; |
| int flags; |
| { |
| int (*func)() = (flags & PEXECUTE_SEARCH ? execvp : execv); |
| int pid; |
| int pdes[2]; |
| int input_desc, output_desc; |
| int retries, sleep_interval; |
| /* Pipe waiting from last process, to be used as input for the next one. |
| Value is STDIN_FILE_NO if no pipe is waiting |
| (i.e. the next command is the first of a group). */ |
| static int last_pipe_input; |
| |
| /* If this is the first process, initialize. */ |
| if (flags & PEXECUTE_FIRST) |
| last_pipe_input = STDIN_FILE_NO; |
| |
| input_desc = last_pipe_input; |
| |
| /* If this isn't the last process, make a pipe for its output, |
| and record it as waiting to be the input to the next process. */ |
| if (! (flags & PEXECUTE_LAST)) |
| { |
| if (pipe (pdes) < 0) |
| { |
| *errmsg_fmt = "pipe"; |
| *errmsg_arg = NULL; |
| return -1; |
| } |
| output_desc = pdes[WRITE_PORT]; |
| last_pipe_input = pdes[READ_PORT]; |
| } |
| else |
| { |
| /* Last process. */ |
| output_desc = STDOUT_FILE_NO; |
| last_pipe_input = STDIN_FILE_NO; |
| } |
| |
| /* Fork a subprocess; wait and retry if it fails. */ |
| sleep_interval = 1; |
| pid = -1; |
| for (retries = 0; retries < 4; retries++) |
| { |
| pid = fork (); |
| if (pid >= 0) |
| break; |
| sleep (sleep_interval); |
| sleep_interval *= 2; |
| } |
| |
| switch (pid) |
| { |
| case -1: |
| *errmsg_fmt = "fork"; |
| *errmsg_arg = NULL; |
| return -1; |
| |
| case 0: /* child */ |
| /* Move the input and output pipes into place, if necessary. */ |
| if (input_desc != STDIN_FILE_NO) |
| { |
| close (STDIN_FILE_NO); |
| dup (input_desc); |
| close (input_desc); |
| } |
| if (output_desc != STDOUT_FILE_NO) |
| { |
| close (STDOUT_FILE_NO); |
| dup (output_desc); |
| close (output_desc); |
| } |
| |
| /* Close the parent's descs that aren't wanted here. */ |
| if (last_pipe_input != STDIN_FILE_NO) |
| close (last_pipe_input); |
| |
| /* Exec the program. */ |
| (*func) (program, argv); |
| |
| fprintf (stderr, "%s: ", this_pname); |
| fprintf (stderr, install_error_msg, program); |
| fprintf (stderr, ": %s\n", xstrerror (errno)); |
| exit (-1); |
| /* NOTREACHED */ |
| return 0; |
| |
| default: |
| /* In the parent, after forking. |
| Close the descriptors that we made for this child. */ |
| if (input_desc != STDIN_FILE_NO) |
| close (input_desc); |
| if (output_desc != STDOUT_FILE_NO) |
| close (output_desc); |
| |
| /* Return child's process number. */ |
| return pid; |
| } |
| } |
| |
| int |
| pwait (pid, status, flags) |
| int pid; |
| int *status; |
| int flags ATTRIBUTE_UNUSED; |
| { |
| /* ??? Here's an opportunity to canonicalize the values in STATUS. |
| Needed? */ |
| pid = waitpid (pid, status, 0); |
| return pid; |
| } |