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
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
|
#include <_proc.h>
#include <ctype.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void
usage(void)
{
fprintf(stderr, "usage: ps [path]\n");
exit(1);
}
int
main(int argc, const char *argv[])
{
const char *path = argc >= 2 ? argv[1] : "/proc/";
if (argc > 2) usage();
char *readbuf = malloc(4096);
char *procbuf = malloc(4096);
FILE *f = fopen(path, "r");
if (!f) {
err(1, "couldn't open %s", path);
}
// TODO library for iterating over directories
for (;;) {
int len = fread(readbuf, 1, 4096, f);
if (len <= 0) break;
for (int pos = 0; pos < len; ) {
char *end = memchr(readbuf + pos, 0, len - pos);
if (!end) {
errx(1, "unimplemented: buffer overflow");
}
size_t entryl = end - (readbuf+pos) + 1;
if (isdigit(readbuf[pos])) {
FILE *g;
sprintf(procbuf, "%s%smem", path, readbuf+pos);
g = fopen(procbuf, "r");
if (!g) {
warn("couldn't open \"%s\"", procbuf);
strcpy(procbuf, "(can't peek)");
} else {
fseek(g, (long)&_psdata_loc->desc, SEEK_SET);
if (fread(procbuf, 1, 128, g) <= 0) {
strcpy(procbuf, "(no psdata)");
}
procbuf[128] = '\0';
fclose(g);
}
end[-1] = '\0'; /* remove trailing slash */
printf("%s\t%s\n", readbuf+pos, procbuf);
}
pos += entryl;
}
}
free(readbuf);
free(procbuf);
fclose(f);
return 0;
}
|
