libio/tst-ftell-append.c

   1 /* Verify that ftell returns the correct value after a read and a write on a
   2    file opened in a+ mode.
   3    Copyright (C) 2014-2022 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   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.
  10
  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.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <errno.h>
  24 #include <unistd.h>
  25 #include <locale.h>
  26 #include <wchar.h>
  27
  28 /* data points to either char_data or wide_data, depending on whether we're
  29    testing regular file mode or wide mode respectively.  Similarly,
  30    fputs_func points to either fputs or fputws.  data_len keeps track of the
  31    length of the current data and file_len maintains the current file
  32    length.  */
  33 #define BUF_LEN 4
  34 static void *buf;
  35 static char char_buf[BUF_LEN];
  36 static wchar_t wide_buf[BUF_LEN];
  37 static const void *data;
  38 static const char *char_data = "abcdefghijklmnopqrstuvwxyz";
  39 static const wchar_t *wide_data = L"abcdefghijklmnopqrstuvwxyz";
  40 static size_t data_len;
  41 static size_t file_len;
  42
  43 typedef int (*fputs_func_t) (const void *data, FILE *fp);
  44 fputs_func_t fputs_func;
  45
  46 typedef void *(*fgets_func_t) (void *s, int size, FILE *stream);
  47 fgets_func_t fgets_func;
  48
  49 static int do_test (void);
  50
  51 #define TEST_FUNCTION do_test ()
  52 #include "../test-skeleton.c"
  53
  54 static FILE *
  55 init_file (const char *filename)
  56 {
  57   FILE *fp = fopen (filename, "w");
  58   if (fp == NULL)
  59     {
  60       printf ("fopen: %m\n");
  61       return NULL;
  62     }
  63
  64   int written = fputs_func (data, fp);
  65
  66   if (written == EOF)
  67     {
  68       printf ("fputs failed to write data\n");
  69       fclose (fp);
  70       return NULL;
  71     }
  72
  73   file_len = data_len;
  74
  75   fclose (fp);
  76
  77   fp = fopen (filename, "a+");
  78   if (fp == NULL)
  79     {
  80       printf ("fopen(a+): %m\n");
  81       return NULL;
  82     }
  83
  84   return fp;
  85 }
  86
  87 static int
  88 do_one_test (const char *filename)
  89 {
  90   FILE *fp = init_file (filename);
  91
  92   if (fp == NULL)
  93     return 1;
  94
  95   void *ret = fgets_func (buf, BUF_LEN, fp);
  96
  97   if (ret == NULL)
  98     {
  99       printf ("read failed: %m\n");
 100       fclose (fp);
 101       return 1;
 102     }
 103
 104   int written = fputs_func (data, fp);
 105
 106   if (written == EOF)
 107     {
 108       printf ("fputs failed to write data\n");
 109       fclose (fp);
 110       return 1;
 111     }
 112
 113   file_len += data_len;
 114
 115   long off = ftell (fp);
 116
 117   if (off != file_len)
 118     {
 119       printf ("Incorrect offset %ld, expected %zu\n", off, file_len);
 120       fclose (fp);
 121       return 1;
 122     }
 123   else
 124     printf ("Correct offset %ld after write.\n", off);
 125
 126   return 0;
 127 }
 128
 129 /* Run the tests for regular files and wide mode files.  */
 130 static int
 131 do_test (void)
 132 {
 133   int ret = 0;
 134   char *filename;
 135   int fd = create_temp_file ("tst-ftell-append-tmp.", &filename);
 136
 137   if (fd == -1)
 138     {
 139       printf ("create_temp_file: %m\n");
 140       return 1;
 141     }
 142
 143   close (fd);
 144
 145   /* Tests for regular files.  */
 146   puts ("Regular mode:");
 147   fputs_func = (fputs_func_t) fputs;
 148   fgets_func = (fgets_func_t) fgets;
 149   data = char_data;
 150   buf = char_buf;
 151   data_len = strlen (char_data);
 152   ret |= do_one_test (filename);
 153
 154   /* Tests for wide files.  */
 155   puts ("Wide mode:");
 156   if (setlocale (LC_ALL, "en_US.UTF-8") == NULL)
 157     {
 158       printf ("Cannot set en_US.UTF-8 locale.\n");
 159       return 1;
 160     }
 161   fputs_func = (fputs_func_t) fputws;
 162   fgets_func = (fgets_func_t) fgetws;
 163   data = wide_data;
 164   buf = wide_buf;
 165   data_len = wcslen (wide_data);
 166   ret |= do_one_test (filename);
 167
 168   return ret;
 169 }