tests/test-ptsname.c

   1 /* Test of ptsname(3).
   2    Copyright (C) 2010-2025 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 #include <config.h>
  18
  19 #include <stdlib.h>
  20
  21 #include "signature.h"
  22 SIGNATURE_CHECK (ptsname, char *, (int));
  23
  24 #include <errno.h>
  25 #include <fcntl.h>
  26 #include <signal.h>
  27 #include <stdio.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30 #include <sys/stat.h>
  31
  32 #include "same-inode.h"
  33
  34 #include "macros.h"
  35
  36 /* Compare two slave names.
  37    On some systems, there are hard links in the /dev/ directory.
  38    For example, on OSF/1 5.1,
  39      /dev/ttyp0 == /dev/pts/0
  40      /dev/ttyp9 == /dev/pts/9
  41      /dev/ttypa == /dev/pts/10
  42      /dev/ttype == /dev/pts/14
  43  */
  44 static int
  45 same_slave (const char *slave_name1, const char *slave_name2)
  46 {
  47   struct stat statbuf1;
  48   struct stat statbuf2;
  49
  50   return (strcmp (slave_name1, slave_name2) == 0
  51           || (stat (slave_name1, &statbuf1) >= 0
  52               && stat (slave_name2, &statbuf2) >= 0
  53               && psame_inode (&statbuf1, &statbuf2)));
  54 }
  55
  56 int
  57 main (void)
  58 {
  59 #if HAVE_DECL_ALARM
  60   /* Declare failure if test takes too long, by using default abort
  61      caused by SIGALRM.  */
  62 # if defined _AIX
  63   int alarm_value = 20;
  64 # else
  65   int alarm_value = 5;
  66 # endif
  67   signal (SIGALRM, SIG_DFL);
  68   alarm (alarm_value);
  69 #endif
  70
  71   {
  72     char *result;
  73
  74     errno = 0;
  75     result = ptsname (-1);
  76     ASSERT (result == NULL);
  77     ASSERT (errno == EBADF
  78             || errno == ENOTTY /* seen on glibc */
  79            );
  80   }
  81
  82   {
  83     int fd;
  84     char *result;
  85
  86     /* Open the controlling tty of the current process.  */
  87     fd = open ("/dev/tty", O_RDONLY);
  88     if (fd < 0)
  89       {
  90         if (test_exit_status != EXIT_SUCCESS)
  91           return test_exit_status;
  92         fprintf (stderr, "Skipping test: cannot open controlling tty\n");
  93         return 77;
  94       }
  95
  96     result = ptsname (fd);
  97     /* The result is usually NULL, because /dev/tty is a slave, not a
  98        master.  */
  99     if (result != NULL)
 100       {
 101         ASSERT (memcmp (result, "/dev/", 5) == 0);
 102       }
 103
 104     close (fd);
 105   }
 106
 107 #if defined __sun || defined __DragonFly__
 108   /* Solaris has BSD-style /dev/pty[p-r][0-9a-f] files, but the function
 109      ptsname() does not work on them.
 110      DragonFly BSD has only /dev/ptmx.  */
 111   {
 112     int fd;
 113     char *result;
 114
 115     /* Open the controlling tty of the current process.  */
 116     fd = open ("/dev/ptmx", O_RDWR | O_NOCTTY);
 117     if (fd < 0)
 118       {
 119         if (test_exit_status != EXIT_SUCCESS)
 120           return test_exit_status;
 121         fprintf (stderr, "Skipping test: cannot open pseudo-terminal\n");
 122         return 77;
 123       }
 124
 125     result = ptsname (fd);
 126     ASSERT (result != NULL);
 127     ASSERT (memcmp (result, "/dev/pts/", 9) == 0);
 128
 129     close (fd);
 130   }
 131
 132 #elif defined _AIX
 133   /* AIX has BSD-style /dev/ptyp[0-9a-f] files, and the function ptsname()
 134      produces the corresponding /dev/ttyp[0-9a-f] file for each.  But opening
 135      such a pty causes the process to hang in a state where it does not even
 136      react to the SIGALRM signal for N * 15 seconds, where N is the number of
 137      opened ptys, either in the close (fd) call or - when this close (fd) call
 138      is commented out - at the process exit.
 139      So, better don't use these BSD-style ptys.  The modern way to open a pty
 140      is to go through /dev/ptc.  */
 141   {
 142     int fd;
 143     char *result;
 144
 145     /* Open a pty master.  */
 146     fd = open ("/dev/ptc", O_RDWR | O_NOCTTY);
 147     if (fd < 0)
 148       {
 149         if (test_exit_status != EXIT_SUCCESS)
 150           return test_exit_status;
 151         fprintf (stderr, "Skipping test: cannot open pseudo-terminal\n");
 152         return 77;
 153       }
 154
 155     result = ptsname (fd);
 156     ASSERT (result != NULL);
 157     ASSERT (memcmp (result, "/dev/pts/", 9) == 0);
 158
 159     /* This close (fd) call takes 15 seconds.  It would be interruptible by the
 160        SIGALRM timer, but then this test would report failure.  */
 161     close (fd);
 162   }
 163
 164 #elif defined __GNU__ /* Hurd */
 165
 166   /* Try various master names of Hurd: /dev/pty[p-q][0-9a-v]  */
 167   {
 168     int char1;
 169     int char2;
 170
 171     for (char1 = 'p'; char1 <= 'q'; char1++)
 172       for (char2 = '0'; char2 <= 'v'; (char2 == '9' ? char2 = 'a' : char2++))
 173         {
 174           char master_name[32];
 175           int fd;
 176
 177           sprintf (master_name, "/dev/pty%c%c", char1, char2);
 178           fd = open (master_name, O_RDONLY);
 179           if (fd >= 0)
 180             {
 181               char *result;
 182               char slave_name[32];
 183
 184               result = ptsname (fd);
 185               ASSERT (result != NULL);
 186               sprintf (slave_name, "/dev/tty%c%c", char1, char2);
 187               ASSERT (same_slave (result, slave_name));
 188
 189               close (fd);
 190             }
 191         }
 192   }
 193
 194 #else
 195
 196   /* Try various master names of Mac OS X: /dev/pty[p-w][0-9a-f]  */
 197   {
 198     int char1;
 199     int char2;
 200
 201     for (char1 = 'p'; char1 <= 'w'; char1++)
 202       for (char2 = '0'; char2 <= 'f'; (char2 == '9' ? char2 = 'a' : char2++))
 203         {
 204           char master_name[32];
 205           int fd;
 206
 207           sprintf (master_name, "/dev/pty%c%c", char1, char2);
 208           fd = open (master_name, O_RDONLY);
 209           if (fd >= 0)
 210             {
 211               char *result;
 212               char slave_name[32];
 213
 214               result = ptsname (fd);
 215               ASSERT (result != NULL);
 216               sprintf (slave_name, "/dev/tty%c%c", char1, char2);
 217               ASSERT (same_slave (result, slave_name));
 218
 219               close (fd);
 220             }
 221         }
 222   }
 223
 224   /* Try various master names of *BSD: /dev/pty[p-sP-S][0-9a-v]  */
 225   {
 226     int upper;
 227     int char1;
 228     int char2;
 229
 230     for (upper = 0; upper <= 1; upper++)
 231       for (char1 = (upper ? 'P' : 'p'); char1 <= (upper ? 'S' : 's'); char1++)
 232         for (char2 = '0'; char2 <= 'v'; (char2 == '9' ? char2 = 'a' : char2++))
 233           {
 234             char master_name[32];
 235             int fd;
 236
 237             sprintf (master_name, "/dev/pty%c%c", char1, char2);
 238             fd = open (master_name, O_RDONLY);
 239             if (fd >= 0)
 240               {
 241                 char *result;
 242                 char slave_name[32];
 243
 244                 result = ptsname (fd);
 245                 ASSERT (result != NULL);
 246                 sprintf (slave_name, "/dev/tty%c%c", char1, char2);
 247                 ASSERT (same_slave (result, slave_name));
 248
 249                 close (fd);
 250               }
 251           }
 252   }
 253
 254 #endif
 255
 256   return test_exit_status;
 257 }