Updated to fedora-glibc-20071212T1051
[glibc.git] / posix / tst-fork.c
bloba9d468eada517afab30dc8deb8f2051b54d30c92
1 /* Tests for fork.
2 Copyright (C) 2000 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 2000.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA. */
21 #include <errno.h>
22 #include <error.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <unistd.h>
26 #include <wait.h>
29 static const char testdata[] = "This is a test";
30 static const char testdata2[] = "And here we go again";
33 int
34 main (void)
36 const char *tmpdir = getenv ("TMPDIR");
37 char buf[100];
38 size_t tmpdirlen;
39 char *name;
40 int fd;
41 pid_t pid;
42 pid_t ppid;
43 off_t off;
44 int status;
46 if (tmpdir == NULL || *tmpdir == '\0')
47 tmpdir = "/tmp";
48 tmpdirlen = strlen (tmpdir);
50 name = (char *) malloc (tmpdirlen + strlen ("/forkXXXXXX") + 1);
51 if (name == NULL)
52 error (EXIT_FAILURE, errno, "cannot allocate file name");
54 mempcpy (mempcpy (name, tmpdir, tmpdirlen),
55 "/forkXXXXXX", sizeof ("/forkXXXXXX"));
57 /* Open our test file. */
58 fd = mkstemp (name);
59 if (fd == -1)
60 error (EXIT_FAILURE, errno, "cannot open test file `%s'", name);
62 /* Make sure it gets removed. */
63 unlink (name);
65 /* Write some data. */
66 if (write (fd, testdata, strlen (testdata)) != strlen (testdata))
67 error (EXIT_FAILURE, errno, "cannot write test data");
69 /* Get the position in the stream. */
70 off = lseek (fd, 0, SEEK_CUR);
71 if (off == (off_t) -1 || off != strlen (testdata))
72 error (EXIT_FAILURE, errno, "wrong file position");
74 /* Get the parent PID. */
75 ppid = getpid ();
77 /* Now fork of the process. */
78 pid = fork ();
79 if (pid == 0)
81 /* One little test first: the PID must have changed. */
82 if (getpid () == ppid)
83 error (EXIT_FAILURE, 0, "child and parent have same PID");
85 /* Test the `getppid' function. */
86 pid = getppid ();
87 if (pid == (pid_t) -1 ? errno != ENOSYS : pid != ppid)
88 error (EXIT_FAILURE, 0,
89 "getppid returned wrong PID (%ld, should be %ld)",
90 (long int) pid, (long int) ppid);
92 /* This is the child. First get the position of the descriptor. */
93 off = lseek (fd, 0, SEEK_CUR);
94 if (off == (off_t) -1 || off != strlen (testdata))
95 error (EXIT_FAILURE, errno, "wrong file position in child");
97 /* Reset the position. */
98 if (lseek (fd, 0, SEEK_SET) != 0)
99 error (EXIT_FAILURE, errno, "cannot reset position in child");
101 /* Read the data. */
102 if (read (fd, buf, sizeof buf) != strlen (testdata))
103 error (EXIT_FAILURE, errno, "cannot read data in child");
105 /* Compare the data. */
106 if (memcmp (buf, testdata, strlen (testdata)) != 0)
107 error (EXIT_FAILURE, 0, "data comparison failed in child");
109 /* Reset position again. */
110 if (lseek (fd, 0, SEEK_SET) != 0)
111 error (EXIT_FAILURE, errno, "cannot reset position again in child");
113 /* Write new data. */
114 if (write (fd, testdata2, strlen (testdata2)) != strlen (testdata2))
115 error (EXIT_FAILURE, errno, "cannot write new data in child");
117 /* Close the file. This must not remove it. */
118 close (fd);
120 _exit (0);
122 else if (pid < 0)
123 /* Something went wrong. */
124 error (EXIT_FAILURE, errno, "cannot fork");
126 /* Wait for the child. */
127 if (waitpid (pid, &status, 0) != pid)
128 error (EXIT_FAILURE, 0, "Oops, wrong test program terminated");
130 if (WTERMSIG (status) != 0)
131 error (EXIT_FAILURE, 0, "Child terminated incorrectly");
132 status = WEXITSTATUS (status);
134 if (status == 0)
136 /* Test whether the child wrote the right data. First test the
137 position. It must be the same as in the child. */
138 if (lseek (fd, 0, SEEK_CUR) != strlen (testdata2))
139 error (EXIT_FAILURE, 0, "file position not changed");
141 if (lseek (fd, 0, SEEK_SET) != 0)
142 error (EXIT_FAILURE, errno, "cannot reset file position");
144 if (read (fd, buf, sizeof buf) != strlen (testdata2))
145 error (EXIT_FAILURE, errno, "cannot read new data");
147 if (memcmp (buf, testdata2, strlen (testdata2)) != 0)
148 error (EXIT_FAILURE, 0, "new data not read correctly");
151 return status;