/* Test setvbuf on readonly fopen (using mmap stdio). Copyright (C) 2002-2016 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Jakub Jelinek , 2002. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ #include #include #include #include int main (void) { char name[] = "/tmp/tst-mmap-setvbuf.XXXXXX"; char buf[4096]; const char * const test = "Let's see if mmap stdio works with setvbuf.\n"; char temp[strlen (test) + 1]; int fd = mkstemp (name); FILE *f; if (fd == -1) { printf ("%u: cannot open temporary file: %m\n", __LINE__); exit (1); } f = fdopen (fd, "w"); if (f == NULL) { printf ("%u: cannot fdopen temporary file: %m\n", __LINE__); exit (1); } fputs (test, f); fclose (f); f = fopen (name, "rm"); if (f == NULL) { printf ("%u: cannot fopen temporary file: %m\n", __LINE__); exit (1); } if (setvbuf (f, buf, _IOFBF, sizeof buf)) { printf ("%u: setvbuf failed: %m\n", __LINE__); exit (1); } if (fread (temp, 1, strlen (test), f) != strlen (test)) { printf ("%u: couldn't read the file back: %m\n", __LINE__); exit (1); } temp [strlen (test)] = '\0'; if (strcmp (test, temp)) { printf ("%u: read different string than was written:\n%s%s", __LINE__, test, temp); exit (1); } fclose (f); unlink (name); exit (0); }