[C]reading /proc/cpuinfo sometimes makes program segfault

[Jordanwb]

This is my program:


#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main (void)
{
FILE *f = fopen ("/proc/cpuinfo", "r");

char *a = malloc (256);
char *b = malloc (128);
char *c = malloc (128);

while (!feof (f))
{
fgets (a, 512, f);

if (strlen (a) == 1) continue;

sscanf (a, "%[^\t:] : %[^\t\n]", b, c);

printf ("%s = %s\n", b, c);
}

fclose (f);
}


This is my desktop machine's cpuinfo: http://pastebin.com/0nk6WfHN

This is my NAS's cpuinfo: http://pastebin.com/ct82bBtU

If I run my program on the NAS, it runs fine although the Serial line is printed twice for some reason. If I run this on my desktop it handles everything okay but prints "power management = 36 bits physical, 48 bits virtual" twice then segfaults and I don't know why.

Thanks in advance.

[xbxb]

Open /proc/cpuinfo and see if there is any information after

power management:

If there is none, that would account for the segfault.
You need to code for that possibility.

[Jordanwb]

Open /proc/cpuinfo and see if there is any information after

power management:

If there is none, that would account for the segfault.
You need to code for that possibility.

the pastebins show the contents of /proc/cpuinfo on my desktop machine and my NAS. On my desktop there's nothing after "power management" which I know is causing the segfault but I don't know what to do about it.

[xbxb]

Don't print strings that never existed.

[Bachstelze]

char *a = malloc (256);
[...]
fgets (a, 512, f);

[Jordanwb]

char *a = malloc (256);
[...]
fgets (a, 512, f);

Oh derp. I didn't notice that thanks.