support/temp_file.c

   1 /* Temporary file handling for tests.
   2    Copyright (C) 1998-2020 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 /* This is required to get an mkstemp which can create large files on
  20    some 32-bit platforms. */
  21 #define _FILE_OFFSET_BITS 64
  22
  23 #include <support/temp_file.h>
  24 #include <support/temp_file-internal.h>
  25 #include <support/support.h>
  26
  27 #include <paths.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32
  33 /* List of temporary files.  */
  34 static struct temp_name_list
  35 {
  36   struct temp_name_list *next;
  37   char *name;
  38   pid_t owner;
  39 } *temp_name_list;
  40
  41 /* Location of the temporary files.  Set by the test skeleton via
  42    support_set_test_dir.  The string is not be freed.  */
  43 static const char *test_dir = _PATH_TMP;
  44
  45 void
  46 add_temp_file (const char *name)
  47 {
  48   struct temp_name_list *newp
  49     = (struct temp_name_list *) xcalloc (sizeof (*newp), 1);
  50   char *newname = strdup (name);
  51   if (newname != NULL)
  52     {
  53       newp->name = newname;
  54       newp->next = temp_name_list;
  55       newp->owner = getpid ();
  56       temp_name_list = newp;
  57     }
  58   else
  59     free (newp);
  60 }
  61
  62 int
  63 create_temp_file (const char *base, char **filename)
  64 {
  65   char *fname;
  66   int fd;
  67
  68   fname = (char *) xmalloc (strlen (test_dir) + 1 + strlen (base)
  69                             + sizeof ("XXXXXX"));
  70   strcpy (stpcpy (stpcpy (stpcpy (fname, test_dir), "/"), base), "XXXXXX");
  71
  72   fd = mkstemp (fname);
  73   if (fd == -1)
  74     {
  75       printf ("cannot open temporary file '%s': %m\n", fname);
  76       free (fname);
  77       return -1;
  78     }
  79
  80   add_temp_file (fname);
  81   if (filename != NULL)
  82     *filename = fname;
  83   else
  84     free (fname);
  85
  86   return fd;
  87 }
  88
  89 char *
  90 support_create_temp_directory (const char *base)
  91 {
  92   char *path = xasprintf ("%s/%sXXXXXX", test_dir, base);
  93   if (mkdtemp (path) == NULL)
  94     {
  95       printf ("error: mkdtemp (\"%s\"): %m", path);
  96       exit (1);
  97     }
  98   add_temp_file (path);
  99   return path;
 100 }
 101
 102 /* Helper functions called by the test skeleton follow.  */
 103
 104 void
 105 support_set_test_dir (const char *path)
 106 {
 107   test_dir = path;
 108 }
 109
 110 void
 111 support_delete_temp_files (void)
 112 {
 113   pid_t pid = getpid ();
 114   while (temp_name_list != NULL)
 115     {
 116       /* Only perform the removal if the path was registed in the same
 117          process, as identified by the PID.  (This assumes that the
 118          parent process which registered the temporary file sticks
 119          around, to prevent PID reuse.)  */
 120       if (temp_name_list->owner == pid)
 121         {
 122           if (remove (temp_name_list->name) != 0)
 123             printf ("warning: could not remove temporary file: %s: %m\n",
 124                     temp_name_list->name);
 125         }
 126       free (temp_name_list->name);
 127
 128       struct temp_name_list *next = temp_name_list->next;
 129       free (temp_name_list);
 130       temp_name_list = next;
 131     }
 132 }
 133
 134 void
 135 support_print_temp_files (FILE *f)
 136 {
 137   if (temp_name_list != NULL)
 138     {
 139       struct temp_name_list *n;
 140       fprintf (f, "temp_files=(\n");
 141       for (n = temp_name_list; n != NULL; n = n->next)
 142         fprintf (f, "  '%s'\n", n->name);
 143       fprintf (f, ")\n");
 144     }
 145 }