libbb/gz_open.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright (C) many different people.  If you wrote this, please
   6  * acknowledge your work.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  21  * USA
  22  */
  23
  24 #include <sys/types.h>
  25 #include <sys/wait.h>
  26 #include <signal.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30 #include "libbb.h"
  31
  32 FILE *
  33 gz_open(FILE *compressed_file, int *pid)
  34 {
  35         int unzip_pipe[2];
  36
  37         if (pipe(unzip_pipe)!=0) {
  38                 perror_msg("%s: pipe", __FUNCTION__);
  39                 return(NULL);
  40         }
  41         if ((*pid = fork()) == -1) {
  42                 perror_msg("%s: fork", __FUNCTION__);
  43                 return(NULL);
  44         }
  45         if (*pid==0) {
  46                 /* child process */
  47                 close(unzip_pipe[0]);
  48                 unzip(compressed_file, fdopen(unzip_pipe[1], "w"));
  49                 fflush(NULL);
  50                 fclose(compressed_file);
  51                 close(unzip_pipe[1]);
  52                 _exit(EXIT_SUCCESS);
  53         }
  54         close(unzip_pipe[1]);
  55         return(fdopen(unzip_pipe[0], "r"));
  56 }
  57
  58 int
  59 gz_close(int gunzip_pid)
  60 {
  61         int status;
  62         int ret;
  63
  64         if (waitpid(gunzip_pid, &status, 0) == -1) {
  65                 perror_msg("%s: waitpid", __FUNCTION__);
  66                 return -1;
  67         }
  68
  69         if (WIFSIGNALED(status)) {
  70                 error_msg("%s: unzip process killed by signal %d\n",
  71                         __FUNCTION__, WTERMSIG(status));
  72                 return -1;
  73         }
  74
  75         if (!WIFEXITED(status)) {
  76                 /* shouldn't happen */
  77                 error_msg("%s: Your system is broken: got status %d from waitpid\n",
  78                                 __FUNCTION__, status);
  79                 return -1;
  80         }
  81
  82         if ((ret = WEXITSTATUS(status))) {
  83                 error_msg("%s: unzip process failed with return code %d.\n",
  84                                 __FUNCTION__, ret);
  85                 return -1;
  86         }
  87
  88         return 0;
  89 }