blob: 66d7336932955f8c637ffa4f4789cd3f4ba5d97a (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include "syscalls.h"
/* The C Programming Language: 2nd Edition
*
* Exercise 8-2: Rewrite `fopen` and `_fillbuf` with fields instead of explicit
* bit operations. Compare code size and execution speed.
*
* Notes: Fields, in this case, are struct fields. I implemented them as 1-bit
* integers to simulate bit fields via struct.
*
* The resulting binary of this file (plus the custom header) runs through this
* source file in about 0.001s. However, the binary is 1KB larger.
*
* Some subsequent exercises use the same syscalls.h file created for this
* exercise. For this reason, the file only refers to its chapter and not
* specific exercises.
*/
int main() {
FILE *fp = fopen("8-02_fopen-and-fillbuf.c", "r");
if (fp != NULL) {
puts("We could read the file.\n");
/* pro tip: don't declare this as 'unsigned' or you'll create an
* endless loop thanks to EOF typically being negative. Don't waste
* half an hour on a newbie mistake like I did. :)
*/
char c;
while ((c = getc(fp)) != EOF) {
putchar(c);
}
/* fclose calls fflush */
fclose(fp);
fclose(stdout);
} else {
puts("Could not open file for reading.");
}
return 0;
}
|
