tests/test-spawn-pipe-main.c

   1 /* Test of create_pipe_bidi/wait_subprocess.
   2    Copyright (C) 2009-2024 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, see <https://www.gnu.org/licenses/>.  */
  16
  17 #include <config.h>
  18
  19 #include "spawn-pipe.h"
  20 #include "wait-process.h"
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26
  27 /* Depending on arguments, this test intentionally closes stderr or
  28    starts life with stderr closed.  So, we arrange to have fd 10
  29    (outside the range of interesting fd's during the test) set up to
  30    duplicate the original stderr.  */
  31
  32 #define BACKUP_STDERR_FILENO 10
  33 #define ASSERT_STREAM myerr
  34 #include "macros.h"
  35
  36 static FILE *myerr;
  37
  38 /* Create a bi-directional pipe to a test child, and validate that the
  39    child program returns the expected output.
  40    PROG is the program to run in the child process.
  41    STDERR_CLOSED is true if we have already closed fd 2.  */
  42 static void
  43 test_pipe (const char *prog, bool stderr_closed)
  44 {
  45   int fd[2];
  46   const char *argv[3];
  47   pid_t pid;
  48   char buffer[2] = { 'a', 't' };
  49
  50   /* Set up child.  */
  51   argv[0] = prog;
  52   argv[1] = (stderr_closed ? "1" : "0");
  53   argv[2] = NULL;
  54   pid = create_pipe_bidi (prog, prog, argv, NULL, false, true, true, fd);
  55   ASSERT (0 <= pid);
  56   ASSERT (STDERR_FILENO < fd[0]);
  57   ASSERT (STDERR_FILENO < fd[1]);
  58
  59   /* Push child's input.  */
  60   ASSERT (write (fd[1], buffer, 1) == 1);
  61   ASSERT (close (fd[1]) == 0);
  62
  63   /* Get child's output.  */
  64   ASSERT (read (fd[0], buffer, 2) == 1);
  65
  66   /* Wait for child.  */
  67   ASSERT (wait_subprocess (pid, prog, true, false, true, true, NULL) == 0);
  68   ASSERT (close (fd[0]) == 0);
  69
  70   /* Check the result.  */
  71   ASSERT (buffer[0] == 'b');
  72   ASSERT (buffer[1] == 't');
  73 }
  74
  75 int
  76 main (int argc, char *argv[])
  77 {
  78   int test;
  79   int fd;
  80
  81   if (argc != 3)
  82     {
  83       fprintf (stderr, "%s: need 2 arguments\n", argv[0]);
  84       return 2;
  85     }
  86   /* We might close fd 2 later, so save it in fd 10.  */
  87   if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
  88       || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
  89     return 2;
  90
  91   /* Selectively close various standard fds, to verify the child process is
  92      not impacted by this.  */
  93   test = atoi (argv[2]);
  94   switch (test)
  95     {
  96     case 0:
  97       break;
  98     case 1:
  99       close (0);
 100       break;
 101     case 2:
 102       close (1);
 103       break;
 104     case 3:
 105       close (0);
 106       close (1);
 107       break;
 108     case 4:
 109       close (2);
 110       break;
 111     case 5:
 112       close (0);
 113       close (2);
 114       break;
 115     case 6:
 116       close (1);
 117       close (2);
 118       break;
 119     case 7:
 120       close (0);
 121       close (1);
 122       close (2);
 123       break;
 124     default:
 125       ASSERT (false);
 126     }
 127
 128   /* Plug any file descriptor leaks inherited from outside world before
 129      starting, so that child has a clean slate (at least for the fds that we
 130      might be manipulating).  */
 131   for (fd = 3; fd < 7; fd++)
 132     close (fd);
 133
 134   test_pipe (argv[1], test >= 4);
 135
 136   return test_exit_status;
 137 }