CODEWITHSUNDEEP
c
Vijay S B
Vijay S B

Reputation: 1315

Parse txBytes,rxBytes,rxPackets,txPackets from /proc/net/dev using c

I tried to Parse txBytes,rxBytes,rxPackets,txPackets from /proc/net/dev using c. Output is not as i expected. Here is the core of my code

while (fgets(buf, sizeof(buf), file) != NULL) {
conv = sscanf( buf, "%[^:]: %Lu %*u %*u %*u %*u %*u %*u %*u %Lu %*u %*u %*u     %*u %*u %*u %*u", ifname, &rxBytes, &txBytes );
    printf("%s %Lu %Lu\n",ifname,rxBytes,txBytes);
    conv = 0;
    ifacesCount++;
 }

Here the file is /proc/net/dev and buf size is 500. I want to extract the interface name,txBytes,rxBytes,rxPackets,txPackets

Upvotes: 1

Views: 2660

Answers (1)

Karthik Nayak
Karthik Nayak

Reputation: 740

From your code sample, I wrote the following:

#include <stdio.h>

int main() {
    FILE *fp = fopen("/proc/net/dev", "r");
    char buf[200], ifname[20];
    unsigned long int r_bytes, t_bytes, r_packets, t_packets;

    // skip first two lines
    for (int i = 0; i < 2; i++) {
        fgets(buf, 200, fp);
    }

    while (fgets(buf, 200, fp)) {
        sscanf(buf, "%[^:]: %lu %lu %*lu %*lu %*lu %*lu %*lu %*lu %lu %lu",
               ifname, &r_bytes, &r_packets, &t_bytes, &t_packets);
        printf("%s: rbytes: %lu rpackets: %lu tbytes: %lu tpackets: %lu\n",
               ifname, r_bytes, r_packets, t_bytes, t_packets);
    }

    fclose(fp);
    return 0;
}

This outputs:

lo: rbytes: 22975300 rpackets: 459506 tbytes: 22975300 tpackets: 459506
wlp2s0: rbytes: 2419131107 rpackets: 1820658 tbytes: 109438292 tpackets: 877583
eno1: rbytes: 15984078 rpackets: 55391 tbytes: 3078636 tpackets: 13019

Hope that helps you :)

Upvotes: 2

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