libopkg/xsystem.c

   1 /* xsystem.c - system(3) with error messages
   2
   3    Carl D. Worth
   4
   5    Copyright (C) 2001 University of Southern California
   6
   7    This program is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU General Public License as
   9    published by the Free Software Foundation; either version 2, or (at
  10    your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful, but
  13    WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    General Public License for more details.
  16 */
  17
  18 #include "includes.h"
  19 #include <sys/wait.h>
  20
  21 #include "xsystem.h"
  22
  23 /* XXX: FEATURE: I shouldn't actually use system(3) at all. I don't
  24    really need the /bin/sh invocation which takes resources and
  25    introduces security problems. I should switch all of this to a sort
  26    of execl() or execv() interface/implementation.
  27 */
  28
  29 /* Like system(3), but with error messages printed if the fork fails
  30    or if the child process dies due to an uncaught signal. Also, the
  31    return value is a bit simpler:
  32
  33    -1 if there was any problem
  34    Otherwise, the 8-bit return value of the program ala WEXITSTATUS
  35    as defined in <sys/wait.h>.
  36 */
  37 int xsystem(const char *cmd)
  38 {
  39     int err;
  40
  41     err = system(cmd);
  42
  43     if (err == -1) {
  44         fprintf(stderr, "%s: ERROR: fork failed before execution: `%s'\n",
  45                 __FUNCTION__, cmd);
  46         return -1;
  47     }
  48
  49     if (WIFSIGNALED(err)) {
  50         fprintf(stderr, "%s: ERROR: Child process died due to signal %d: `%s'\n",
  51                 __FUNCTION__, WTERMSIG(err), cmd);
  52         return -1;
  53     }
  54
  55     if (WIFEXITED(err)) {
  56         /* Normal child exit */
  57         return WEXITSTATUS(err);
  58     }
  59
  60     fprintf(stderr, "%s: ERROR: Received unintelligible return value from system: %d",
  61             __FUNCTION__, err);
  62     return -1;
  63 }
  64