On Wed, Apr 23, 2025 at 05:01:43PM +0200, Thomas Weißschuh wrote:
+static __attribute__((unused)) +FILE *fopen(const char *pathname, const char *mode) +{
- int flags, fd;
- if (!strcmp(mode, "r"))
flags = O_RDONLY;- else if (!strcmp(mode, "w"))
flags = O_WRONLY | O_CREAT | O_TRUNC;- else if (!strcmp(mode, "a"))
flags = O_WRONLY | O_CREAT | O_APPEND;- else if (!strcmp(mode, "r+"))
flags = O_RDWR;- else if (!strcmp(mode, "w+"))
flags = O_RDWR | O_CREAT | O_TRUNC;- else if (!strcmp(mode, "a+"))
flags = O_RDWR | O_CREAT | O_APPEND;- else {
SET_ERRNO(EINVAL);return NULL;- }
I'm concerned by the size of the function due to the repeated strcmp() calls (also I find strcmp()==0 more readable that !strcmp() which I tend to read as "not string compares").
I have not tried the code below but I think it could cover it in a maybe lighter way:
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; default : SET_ERRNO(EINVAL); return NULL; }
if (mode[1] == '+') flags = (flags & ~(O_RDONLY|O_WRONLY)) | O_RDWR;
I think it does the same but should be significantly lighter.
Willy