string/tst-strlcpy.c

   1 /* Test the strlcpy function.
   2    Copyright (C) 2023-2024 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 #include <string.h>
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22 #include <support/check.h>
  23
  24 static int
  25 do_test (void)
  26 {
  27   struct {
  28     char buf1[16];
  29     char buf2[16];
  30   } s;
  31
  32   /* Nothing is written to the destination if its size is 0.  */
  33   memset (&s, '@', sizeof (s));
  34   TEST_COMPARE (strlcpy (s.buf1, "Hello!", 0), 6);
  35   TEST_COMPARE_BLOB (&s, sizeof (s), "@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@", 32);
  36
  37   /* No bytes are are modified in the target buffer if the source
  38      string is short enough.  */
  39   memset (&s, '@', sizeof (s));
  40   TEST_COMPARE (strlcpy (s.buf1, "Hello!", sizeof (s.buf1)), 6);
  41   TEST_COMPARE_BLOB (&s, sizeof (s), "Hello!\0@@@@@@@@@@@@@@@@@@@@@@@@@", 32);
  42
  43   /* A source string which fits exactly into the destination buffer is
  44      not truncated.  */
  45   memset (&s, '@', sizeof (s));
  46   TEST_COMPARE (strlcpy (s.buf1, "Hello, world!!!", sizeof (s.buf1)), 15);
  47   TEST_COMPARE_BLOB (&s, sizeof (s),
  48                      "Hello, world!!!\0@@@@@@@@@@@@@@@@@@@@@@@@@", 32);
  49
  50   /* A source string one character longer than the destination buffer
  51      is truncated by one character.  The untruncated source length is
  52      returned.  */
  53   memset (&s, '@', sizeof (s));
  54   TEST_COMPARE (strlcpy (s.buf1, "Hello, world!!!!", sizeof (s.buf1)), 16);
  55   TEST_COMPARE_BLOB (&s, sizeof (s),
  56                      "Hello, world!!!\0@@@@@@@@@@@@@@@@@@@@@@@@@", 32);
  57
  58   /* An even longer source string is truncated as well, and the
  59      original length is returned.  */
  60   memset (&s, '@', sizeof (s));
  61   TEST_COMPARE (strlcpy (s.buf1, "Hello, world!!!!!!!!", sizeof (s.buf1)), 20);
  62   TEST_COMPARE_BLOB (&s, sizeof (s),
  63                      "Hello, world!!!\0@@@@@@@@@@@@@@@@@@@@@@@@@", 32);
  64
  65   return 0;
  66 }
  67
  68 #include <support/test-driver.c>