libiberty/pex-msdos.c

   1 /* Utilities to execute a program in a subprocess (possibly linked by pipes
   2    with other subprocesses), and wait for it.  Generic MSDOS specialization.
   3    Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2003
   4    Free Software Foundation, Inc.
   5
   6 This file is part of the libiberty library.
   7 Libiberty is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU Library General Public
   9 License as published by the Free Software Foundation; either
  10 version 2 of the License, or (at your option) any later version.
  11
  12 Libiberty is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 Library General Public License for more details.
  16
  17 You should have received a copy of the GNU Library General Public
  18 License along with libiberty; see the file COPYING.LIB.  If not,
  19 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #include "pex-common.h"
  23
  24 #include <stdio.h>
  25 #include <errno.h>
  26 #ifdef NEED_DECLARATION_ERRNO
  27 extern int errno;
  28 #endif
  29 #ifdef HAVE_STRING_H
  30 #include <string.h>
  31 #endif
  32 #ifdef HAVE_STDLIB_H
  33 #include <stdlib.h>
  34 #endif
  35
  36 #include "safe-ctype.h"
  37 #include <process.h>
  38
  39 /* MSDOS doesn't multitask, but for the sake of a consistent interface
  40    the code behaves like it does.  pexecute runs the program, tucks the
  41    exit code away, and returns a "pid".  pwait must be called to fetch the
  42    exit code.  */
  43
  44 /* For communicating information from pexecute to pwait.  */
  45 static int last_pid = 0;
  46 static int last_status = 0;
  47 static int last_reaped = 0;
  48
  49 int
  50 pexecute (const char *program, char * const *argv, const char *this_pname,
  51           const char *temp_base, char **errmsg_fmt, char **errmsg_arg,
  52           int flags)
  53 {
  54   int rc;
  55   char *scmd, *rf;
  56   FILE *argfile;
  57   int i, el = flags & PEXECUTE_SEARCH ? 4 : 0;
  58
  59   last_pid++;
  60   if (last_pid < 0)
  61     last_pid = 1;
  62
  63   if ((flags & PEXECUTE_ONE) != PEXECUTE_ONE)
  64     abort ();
  65
  66   if (temp_base == 0)
  67     temp_base = choose_temp_base ();
  68   scmd = (char *) xmalloc (strlen (program) + strlen (temp_base) + 6 + el);
  69   rf = scmd + strlen(program) + 2 + el;
  70   sprintf (scmd, "%s%s @%s.gp", program,
  71            (flags & PEXECUTE_SEARCH ? ".exe" : ""), temp_base);
  72   argfile = fopen (rf, "w");
  73   if (argfile == 0)
  74     {
  75       int errno_save = errno;
  76       free (scmd);
  77       errno = errno_save;
  78       *errmsg_fmt = "cannot open `%s.gp'";
  79       *errmsg_arg = temp_base;
  80       return -1;
  81     }
  82
  83   for (i=1; argv[i]; i++)
  84     {
  85       char *cp;
  86       for (cp = argv[i]; *cp; cp++)
  87         {
  88           if (*cp == '"' || *cp == '\'' || *cp == '\\' || ISSPACE (*cp))
  89             fputc ('\\', argfile);
  90           fputc (*cp, argfile);
  91         }
  92       fputc ('\n', argfile);
  93     }
  94   fclose (argfile);
  95
  96   rc = system (scmd);
  97
  98   {
  99     int errno_save = errno;
 100     remove (rf);
 101     free (scmd);
 102     errno = errno_save;
 103   }
 104
 105   if (rc == -1)
 106     {
 107       *errmsg_fmt = install_error_msg;
 108       *errmsg_arg = (char *)program;
 109       return -1;
 110     }
 111
 112   /* Tuck the status away for pwait, and return a "pid".  */
 113   last_status = rc << 8;
 114   return last_pid;
 115 }
 116
 117 /* Use ECHILD if available, otherwise use EINVAL.  */
 118 #ifdef ECHILD
 119 #define PWAIT_ERROR ECHILD
 120 #else
 121 #define PWAIT_ERROR EINVAL
 122 #endif
 123
 124 int
 125 pwait (int pid, int *status, int flags)
 126 {
 127   /* On MSDOS each pexecute must be followed by its associated pwait.  */
 128   if (pid != last_pid
 129       /* Called twice for the same child?  */
 130       || pid == last_reaped)
 131     {
 132       errno = PWAIT_ERROR;
 133       return -1;
 134     }
 135   /* ??? Here's an opportunity to canonicalize the values in STATUS.
 136      Needed?  */
 137   *status = last_status;
 138   last_reaped = last_pid;
 139   return last_pid;
 140 }