| /* |
| * fopen.c |
| */ |
| |
| #include <stdio.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| |
| /* This depends on O_RDONLY == 0, O_WRONLY == 1, O_RDWR == 2 */ |
| |
| |
| FILE *fopen(const char *file, const char *mode) |
| { |
| int flags = O_RDONLY; |
| int plus = 0; |
| int fd; |
| |
| while ( *mode ) { |
| switch ( *mode ) { |
| case 'r': |
| flags = O_RDONLY; |
| break; |
| case 'w': |
| flags = O_WRONLY|O_CREAT|O_TRUNC; |
| break; |
| case 'a': |
| flags = O_WRONLY|O_CREAT|O_APPEND; |
| break; |
| case '+': |
| plus = 1; |
| break; |
| } |
| mode++; |
| } |
| |
| if ( plus ) { |
| flags = (flags & ~(O_RDONLY|O_WRONLY)) | O_RDWR; |
| } |
| |
| fd = open(file, flags, 0666); |
| |
| if ( fd < 0 ) |
| return NULL; |
| else |
| return fdopen(fd, mode); |
| } |