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 (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
  51      const char *program;
  52      char * const *argv;
  53      const char *this_pname;
  54      const char *temp_base;
  55      char **errmsg_fmt, **errmsg_arg;
  56      int flags;
  57 {
  58   int rc;
  59   char *scmd, *rf;
  60   FILE *argfile;
  61   int i, el = flags & PEXECUTE_SEARCH ? 4 : 0;
  62
  63   last_pid++;
  64   if (last_pid < 0)
  65     last_pid = 1;
  66
  67   if ((flags & PEXECUTE_ONE) != PEXECUTE_ONE)
  68     abort ();
  69
  70   if (temp_base == 0)
  71     temp_base = choose_temp_base ();
  72   scmd = (char *) xmalloc (strlen (program) + strlen (temp_base) + 6 + el);
  73   rf = scmd + strlen(program) + 2 + el;
  74   sprintf (scmd, "%s%s @%s.gp", program,
  75            (flags & PEXECUTE_SEARCH ? ".exe" : ""), temp_base);
  76   argfile = fopen (rf, "w");
  77   if (argfile == 0)
  78     {
  79       int errno_save = errno;
  80       free (scmd);
  81       errno = errno_save;
  82       *errmsg_fmt = "cannot open `%s.gp'";
  83       *errmsg_arg = temp_base;
  84       return -1;
  85     }
  86
  87   for (i=1; argv[i]; i++)
  88     {
  89       char *cp;
  90       for (cp = argv[i]; *cp; cp++)
  91         {
  92           if (*cp == '"' || *cp == '\'' || *cp == '\\' || ISSPACE (*cp))
  93             fputc ('\\', argfile);
  94           fputc (*cp, argfile);
  95         }
  96       fputc ('\n', argfile);
  97     }
  98   fclose (argfile);
  99
 100   rc = system (scmd);
 101
 102   {
 103     int errno_save = errno;
 104     remove (rf);
 105     free (scmd);
 106     errno = errno_save;
 107   }
 108
 109   if (rc == -1)
 110     {
 111       *errmsg_fmt = install_error_msg;
 112       *errmsg_arg = (char *)program;
 113       return -1;
 114     }
 115
 116   /* Tuck the status away for pwait, and return a "pid".  */
 117   last_status = rc << 8;
 118   return last_pid;
 119 }
 120
 121 /* Use ECHILD if available, otherwise use EINVAL.  */
 122 #ifdef ECHILD
 123 #define PWAIT_ERROR ECHILD
 124 #else
 125 #define PWAIT_ERROR EINVAL
 126 #endif
 127
 128 int
 129 pwait (pid, status, flags)
 130      int pid;
 131      int *status;
 132      int flags;
 133 {
 134   /* On MSDOS each pexecute must be followed by its associated pwait.  */
 135   if (pid != last_pid
 136       /* Called twice for the same child?  */
 137       || pid == last_reaped)
 138     {
 139       errno = PWAIT_ERROR;
 140       return -1;
 141     }
 142   /* ??? Here's an opportunity to canonicalize the values in STATUS.
 143      Needed?  */
 144   *status = last_status;
 145   last_reaped = last_pid;
 146   return last_pid;
 147 }