| /* Tests for fork. |
| Copyright (C) 2000 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@cygnus.com>, 2000. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, write to the Free |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. */ |
| |
| #include <errno.h> |
| #include <error.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <wait.h> |
| |
| |
| static const char testdata[] = "This is a test"; |
| static const char testdata2[] = "And here we go again"; |
| |
| |
| int |
| main (void) |
| { |
| const char *tmpdir = getenv ("TMPDIR"); |
| char buf[100]; |
| size_t tmpdirlen; |
| char *name; |
| int fd; |
| pid_t pid; |
| pid_t ppid; |
| off_t off; |
| int status; |
| |
| if (tmpdir == NULL || *tmpdir == '\0') |
| tmpdir = "/tmp"; |
| tmpdirlen = strlen (tmpdir); |
| |
| name = (char *) malloc (tmpdirlen + strlen ("/forkXXXXXX") + 1); |
| if (name == NULL) |
| error (EXIT_FAILURE, errno, "cannot allocate file name"); |
| |
| mempcpy (mempcpy (name, tmpdir, tmpdirlen), |
| "/forkXXXXXX", sizeof ("/forkXXXXXX")); |
| |
| /* Open our test file. */ |
| fd = mkstemp (name); |
| if (fd == -1) |
| error (EXIT_FAILURE, errno, "cannot open test file `%s'", name); |
| |
| /* Make sure it gets removed. */ |
| unlink (name); |
| |
| /* Write some data. */ |
| if (write (fd, testdata, strlen (testdata)) != strlen (testdata)) |
| error (EXIT_FAILURE, errno, "cannot write test data"); |
| |
| /* Get the position in the stream. */ |
| off = lseek (fd, 0, SEEK_CUR); |
| if (off == (off_t) -1 || off != strlen (testdata)) |
| error (EXIT_FAILURE, errno, "wrong file position"); |
| |
| /* Get the parent PID. */ |
| ppid = getpid (); |
| |
| /* Now fork of the process. */ |
| pid = fork (); |
| if (pid == 0) |
| { |
| /* One little test first: the PID must have changed. */ |
| if (getpid () == ppid) |
| error (EXIT_FAILURE, 0, "child and parent have same PID"); |
| |
| /* Test the `getppid' function. */ |
| pid = getppid (); |
| if (pid == (pid_t) -1 ? errno != ENOSYS : pid != ppid) |
| error (EXIT_FAILURE, 0, |
| "getppid returned wrong PID (%ld, should be %ld)", |
| (long int) pid, (long int) ppid); |
| |
| /* This is the child. First get the position of the descriptor. */ |
| off = lseek (fd, 0, SEEK_CUR); |
| if (off == (off_t) -1 || off != strlen (testdata)) |
| error (EXIT_FAILURE, errno, "wrong file position in child"); |
| |
| /* Reset the position. */ |
| if (lseek (fd, 0, SEEK_SET) != 0) |
| error (EXIT_FAILURE, errno, "cannot reset position in child"); |
| |
| /* Read the data. */ |
| if (read (fd, buf, sizeof buf) != strlen (testdata)) |
| error (EXIT_FAILURE, errno, "cannot read data in child"); |
| |
| /* Compare the data. */ |
| if (memcmp (buf, testdata, strlen (testdata)) != 0) |
| error (EXIT_FAILURE, 0, "data comparison failed in child"); |
| |
| /* Reset position again. */ |
| if (lseek (fd, 0, SEEK_SET) != 0) |
| error (EXIT_FAILURE, errno, "cannot reset position again in child"); |
| |
| /* Write new data. */ |
| if (write (fd, testdata2, strlen (testdata2)) != strlen (testdata2)) |
| error (EXIT_FAILURE, errno, "cannot write new data in child"); |
| |
| /* Close the file. This must not remove it. */ |
| close (fd); |
| |
| _exit (0); |
| } |
| else if (pid < 0) |
| /* Something went wrong. */ |
| error (EXIT_FAILURE, errno, "cannot fork"); |
| |
| /* Wait for the child. */ |
| if (waitpid (pid, &status, 0) != pid) |
| error (EXIT_FAILURE, 0, "Oops, wrong test program terminated"); |
| |
| if (WTERMSIG (status) != 0) |
| error (EXIT_FAILURE, 0, "Child terminated incorrectly"); |
| status = WEXITSTATUS (status); |
| |
| if (status == 0) |
| { |
| /* Test whether the child wrote the right data. First test the |
| position. It must be the same as in the child. */ |
| if (lseek (fd, 0, SEEK_CUR) != strlen (testdata2)) |
| error (EXIT_FAILURE, 0, "file position not changed"); |
| |
| if (lseek (fd, 0, SEEK_SET) != 0) |
| error (EXIT_FAILURE, errno, "cannot reset file position"); |
| |
| if (read (fd, buf, sizeof buf) != strlen (testdata2)) |
| error (EXIT_FAILURE, errno, "cannot read new data"); |
| |
| if (memcmp (buf, testdata2, strlen (testdata2)) != 0) |
| error (EXIT_FAILURE, 0, "new data not read correctly"); |
| } |
| |
| return status; |
| } |