1 /* Test of reopening a stream.
2    Copyright (C) 2009-2018 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 of the License, or
7    (at your option) 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 /* Written by Eric Blake <ebb9@byu.net>, 2009.  */
18 
19 #include <config.h>
20 
21 /* Specification.  */
22 #include "stdio--.h"
23 
24 /* Helpers.  */
25 #include <unistd.h>
26 
27 /* This test intentionally closes stderr.  So, we arrange to have fd 10
28    (outside the range of interesting fd's during the test) set up to
29    duplicate the original stderr.  */
30 
31 #define BACKUP_STDERR_FILENO 10
32 #define ASSERT_STREAM myerr
33 #include "macros.h"
34 
35 static FILE *myerr;
36 
37 int
main(void)38 main (void)
39 {
40   FILE *fp;
41 
42   /* We close fd 2 later, so save it in fd 10.  */
43   if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
44       || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
45     return 2;
46 
47   {
48     FILE *tmp;
49     ASSERT (tmp = fopen ("/dev/null", "r"));
50     ASSERT (STDERR_FILENO < fileno (tmp));
51     ASSERT (fp = fopen ("/dev/null", "w"));
52     ASSERT (fileno (tmp) < fileno (fp));
53     ASSERT (fclose (tmp) == 0);
54   }
55 
56   /* Gap in fds.  */
57   ASSERT (freopen ("/dev/null", "r+", fp) == fp);
58   ASSERT (STDERR_FILENO < fileno (fp));
59 
60   ASSERT (freopen ("/dev/null", "r", stdin) == stdin);
61   ASSERT (STDIN_FILENO == fileno (stdin));
62 
63   ASSERT (freopen ("/dev/null", "w", stdout) == stdout);
64   ASSERT (STDOUT_FILENO == fileno (stdout));
65 
66   ASSERT (freopen ("/dev/null", "w", stderr) == stderr);
67   ASSERT (STDERR_FILENO == fileno (stderr));
68 
69   /* fd 0 closed.  */
70   ASSERT (close (STDIN_FILENO) == 0);
71 
72   ASSERT (freopen ("/dev/null", "w", stdout) == stdout);
73   ASSERT (STDOUT_FILENO == fileno (stdout));
74 
75   ASSERT (freopen ("/dev/null", "w", stderr) == stderr);
76   ASSERT (STDERR_FILENO == fileno (stderr));
77 
78   ASSERT (freopen ("/dev/null", "a", fp) == fp);
79   ASSERT (STDERR_FILENO < fileno (fp));
80 
81   /* fd 1 closed.  */
82   ASSERT (close (STDOUT_FILENO) == 0);
83 
84   ASSERT (freopen ("/dev/null", "w", stderr) == stderr);
85   ASSERT (STDERR_FILENO == fileno (stderr));
86 
87   ASSERT (freopen ("/dev/null", "a+", fp) == fp);
88   ASSERT (STDERR_FILENO < fileno (fp));
89 
90   /* fd 2 closed.  */
91   ASSERT (close (STDERR_FILENO) == 0);
92 
93   ASSERT (freopen ("/dev/null", "w+", fp) == fp);
94   ASSERT (STDERR_FILENO < fileno (fp));
95 
96   return 0;
97 }
98