Commit b695298775c2affa4b1e34eccb972e8c84b73243 - The-Dipple

Fix up the mmap() example a bit. catseye 12 years ago

1 changed file(s) with 19 addition(s) and 16 deletion(s). Raw diff Collapse all Expand all

+19

-16

c/mmap.c less more

2	2	#include <sys/types.h>
3	3
4	4	#include <stdio.h>
5		#include <stdlib.h>
6	5	#include <fcntl.h>
	6	#include <unistd.h>
7	7
8	8	int main(int argc, char **argv)
9	9	{

15	15	fd = open(argv[1], O_RDONLY);
16	16	if (fd == -1) {
17	17	perror("Can't open file for reading");
18		exit(1);
	18	return 1;
19	19	}
20	20	fstat(fd, &fileinfo);
21	21
22		buffer = mmap(0, fileinfo.st_size, PROT_READ, MAP_SHARED, fd, 0);
23		if (buffer == MAP_FAILED) {
24		close(fd);
25		perror("Can't mmap the file");
26		exit(1);
	22	if (fileinfo.st_size > 0) {
	23	buffer = mmap(0, fileinfo.st_size, PROT_READ, MAP_SHARED, fd, 0);
	24	if (buffer == MAP_FAILED) {
	25	close(fd);
	26	perror("Can't mmap the file");
	27	return 1;
	28	}
	29
	30	ptr = buffer;
	31	for (i = 0; i < fileinfo.st_size; i++) {
	32	printf("%c", *ptr);
	33	ptr++;
	34	}
	35
	36	if (munmap(buffer, fileinfo.st_size) == -1) {
	37	perror("Can't un-mmap the file");
	38	}
27	39	}
28	40
29		ptr = buffer;
30		for (i = 0; i < fileinfo.st_size; i++) {
31		printf("%c", *ptr);
32		ptr++;
33		}
34
35		if (munmap(buffer, fileinfo.st_size) == -1) {
36		perror("Can't un-mmap the file");
37		}
38	41	close(fd);
39	42	return 0;
40	43	}