| /* Test the read() function. |
| Copyright (C) 2011-2020 Free Software Foundation, Inc. |
| |
| This program is free software: you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program 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 General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| |
| #include <config.h> |
| |
| #include <unistd.h> |
| |
| #include "signature.h" |
| SIGNATURE_CHECK (read, ssize_t, (int, void *, size_t)); |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <string.h> |
| |
| #include "macros.h" |
| |
| int |
| main (void) |
| { |
| const char *filename = "test-read.tmp"; |
| int fd; |
| |
| /* Create a file with a simple contents. */ |
| fd = open (filename, O_CREAT | O_WRONLY, 0600); |
| ASSERT (fd >= 0); |
| ASSERT (write (fd, "Hello World", 11) == 11); |
| ASSERT (close (fd) == 0); |
| |
| /* Read from the middle of the file. */ |
| fd = open (filename, O_RDONLY); |
| ASSERT (fd >= 0); |
| ASSERT (lseek (fd, 6, SEEK_SET) == 6); |
| { |
| char buf[10]; |
| ssize_t ret = read (fd, buf, 10); |
| ASSERT (ret == 5); |
| ASSERT (memcmp (buf, "World", 5) == 0); |
| } |
| ASSERT (close (fd) == 0); |
| |
| /* Test behaviour for invalid file descriptors. */ |
| { |
| char byte; |
| errno = 0; |
| ASSERT (read (-1, &byte, 1) == -1); |
| ASSERT (errno == EBADF); |
| } |
| { |
| char byte; |
| close (99); |
| errno = 0; |
| ASSERT (read (99, &byte, 1) == -1); |
| ASSERT (errno == EBADF); |
| } |
| |
| /* Clean up. */ |
| unlink (filename); |
| |
| return 0; |
| } |