support/temp_file.c

   1 /* Temporary file handling for tests.
   2    Copyright (C) 1998-2021 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_in_dir (const char *base, const char *dir, char **filename)
  64 {
  65   char *fname;
  66   int fd;
  67
  68   fname = xasprintf ("%s/%sXXXXXX", dir, base);
  69
  70   fd = mkstemp (fname);
  71   if (fd == -1)
  72     {
  73       printf ("cannot open temporary file '%s': %m\n", fname);
  74       free (fname);
  75       return -1;
  76     }
  77
  78   add_temp_file (fname);
  79   if (filename != NULL)
  80     *filename = fname;
  81   else
  82     free (fname);
  83
  84   return fd;
  85 }
  86
  87 int
  88 create_temp_file (const char *base, char **filename)
  89 {
  90   return create_temp_file_in_dir (base, test_dir, filename);
  91 }
  92
  93 char *
  94 support_create_temp_directory (const char *base)
  95 {
  96   char *path = xasprintf ("%s/%sXXXXXX", test_dir, base);
  97   if (mkdtemp (path) == NULL)
  98     {
  99       printf ("error: mkdtemp (\"%s\"): %m", path);
 100       exit (1);
 101     }
 102   add_temp_file (path);
 103   return path;
 104 }
 105
 106 /* Helper functions called by the test skeleton follow.  */
 107
 108 void
 109 support_set_test_dir (const char *path)
 110 {
 111   test_dir = path;
 112 }
 113
 114 void
 115 support_delete_temp_files (void)
 116 {
 117   pid_t pid = getpid ();
 118   while (temp_name_list != NULL)
 119     {
 120       /* Only perform the removal if the path was registed in the same
 121          process, as identified by the PID.  (This assumes that the
 122          parent process which registered the temporary file sticks
 123          around, to prevent PID reuse.)  */
 124       if (temp_name_list->owner == pid)
 125         {
 126           if (remove (temp_name_list->name) != 0)
 127             printf ("warning: could not remove temporary file: %s: %m\n",
 128                     temp_name_list->name);
 129         }
 130       free (temp_name_list->name);
 131
 132       struct temp_name_list *next = temp_name_list->next;
 133       free (temp_name_list);
 134       temp_name_list = next;
 135     }
 136 }
 137
 138 void
 139 support_print_temp_files (FILE *f)
 140 {
 141   if (temp_name_list != NULL)
 142     {
 143       struct temp_name_list *n;
 144       fprintf (f, "temp_files=(\n");
 145       for (n = temp_name_list; n != NULL; n = n->next)
 146         fprintf (f, "  '%s'\n", n->name);
 147       fprintf (f, ")\n");
 148     }
 149 }