网络接口流量信息获取

/*
 * Inter-|   Receive                                                |  Transmit
 *  face |bytes    packets errs drop fifo frame compressed multicast|bytes    packets errs drop fifo colls carrier compressed
 *  ens33: 1378627    6509    0    0    0     0          0         0  1046428    4792    0    0    0     0       0          0
 *     lo: 10212375   78449    0    0    0     0          0         0 10212375   78449    0    0    0     0       0          0
 *  ens39:       0       0    0    0    0     0          0         0        0       0    0    0    0     0       0          0
 *  ens38: 16144882   77529    0    0    0     0          0         0   368175    3317    0    0    0     0       0          0
 */

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

#undef long_t
#define long_t long long unsigned 

typedef struct
{
    char iface[32];
    long_t rcv_bytes;
    long_t rcv_packets;
    long_t rcv_errs;
    long_t rcv_drop;
    long_t rcv_fifo;
    long_t rcv_frame;
    long_t rcv_compressed;
    long_t rcv_multicast;

    long_t snd_bytes;
    long_t snd_packets;
    long_t snd_errs;
    long_t snd_drop;
    long_t snd_fifo;
    long_t snd_colls;
    long_t snd_carrier;
    long_t snd_compressed;
}dev_st;

int main()
{
    FILE *fp = NULL;
    char buf[128] = {0};
    dev_st st[10];

    fp = fopen("/proc/net/dev", "r");
    if(fp == NULL) {
        perror("fopen");
        return -1;
    }
    int i = 0;

    fgets(buf, sizeof(buf), fp);
    fgets(buf, sizeof(buf), fp);
    memset(st, 0, sizeof(dev_st));
    while(fgets(buf, sizeof(buf), fp)) {
        {
            // sscanf(buf, "%s %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu",
            sscanf(buf, "%6s: %7llu %7llu %4llu %4llu %4llu %5llu %10llu %9llu %8llu %7llu %4llu %4llu %4llu %5llu %7llu %10llu",
                    st[i].iface,
                    &st[i].rcv_bytes,
                    &st[i].rcv_packets,
                    &st[i].rcv_errs,
                    &st[i].rcv_drop,
                    &st[i].rcv_fifo,
                    &st[i].rcv_frame,
                    &st[i].rcv_compressed,
                    &st[i].rcv_multicast,
                    &st[i].snd_bytes,
                    &st[i].snd_packets,
                    &st[i].snd_errs,
                    &st[i].snd_drop,
                    &st[i].snd_fifo,
                    &st[i].snd_colls,
                    &st[i].snd_carrier,
                    &st[i].snd_compressed);
            st[i].iface[strlen(st[i].iface)-1] = '\0';
        }
        i++;
    }

    for(i=0;i < 2;i ++)
    {
        printf("st[%d].iface:%s\n", i, st[i].iface);
        printf("st[%d].rcv_bytes:%llu\n", i, st[i].rcv_bytes);
        printf("st[%d].rcv_packets:%llu\n", i, st[i].rcv_packets);
        printf("st[%d].rcv_errs:%llu\n", i, st[i].rcv_errs);
        printf("st[%d].rcv_drop:%llu\n", i, st[i].rcv_drop);
        printf("st[%d].rcv_fifo:%llu\n", i, st[i].rcv_fifo);
        printf("st[%d].rcv_frame:%llu\n", i, st[i].rcv_frame);
        printf("st[%d].rcv_compressed:%llu\n", i, st[i].rcv_compressed);
        printf("st[%d].rcv_multicast:%llu\n", i, st[i].rcv_multicast);
        printf("st[%d].snd_bytes:%llu\n", i, st[i].snd_bytes);
        printf("st[%d].snd_packets:%llu\n", i, st[i].snd_packets);
        printf("st[%d].snd_errs:%llu\n", i, st[i].snd_errs);
        printf("st[%d].snd_drop:%llu\n", i, st[i].snd_drop);
        printf("st[%d].snd_fifo:%llu\n", i, st[i].snd_fifo);
        printf("st[%d].snd_colls:%llu\n", i, st[i].snd_colls);
        printf("st[%d].snd_carrier:%llu\n", i, st[i].snd_carrier);
        printf("st[%d].snd_compressed:%llu\n", i, st[i].snd_compressed);
        printf("----------------------------------------------------------\n");
    }


    return 0;
}