linux下获取网络流量的实现方法

仅是通过/proc/net/dev读取其中的数据.(转载)

#include
#include
#include

void skipline(FILE *f)
{
int ch;
do {
ch = getc(f);
} while ( ch != 'n' && ch != EOF );
}

int main(int argc, char *argv[])
{
FILE *pnd;
char buffer[BUFSIZ];
char *interface;
struct ifinfo {
char name[8];
unsigned int r_bytes, r_pkt, r_err, r_drop, r_fifo, r_frame;
unsigned int r_compr, r_mcast;
unsigned int x_bytes, x_pkt, x_err, x_drop, x_fifo, x_coll;
unsigned int x_carrier, x_compr;
} ifc;
unsigned long long bin, bout, lbin, lbout;
int first;

if ( argc != 2 ) {
fprintf(stderr, "Usage: %s interfacen", argv[0]);
exit(1);
}

interface = argv[1];

first = 1;
lbin = 0; lbout = 0;

while ( 1 ) {
pnd = fopen("/proc/net/dev", "r");
if ( !pnd ) {
fprintf(stderr, "%s: /proc/net/dev: %s", argv[0], strerror(errno));
exit(1);
}

/* Skip header */
skipline(pnd);
skipline(pnd);

/* Get interface info */
do {
if ( fscanf(pnd, " %6[^:]:%u %u %u %u %u %u %u %u %u %u %u %u %u %u %u",
&ifc.name,
&ifc.r_bytes, &ifc.r_pkt, &ifc.r_err, &ifc.r_drop,
&ifc.r_fifo, &ifc.r_frame, &ifc.r_compr, &ifc.r_mcast,
&ifc.x_bytes, &ifc.x_pkt, &ifc.x_err, &ifc.x_drop,
&ifc.x_fifo, &ifc.x_coll, &ifc.x_carrier, &ifc.x_compr)
!= 16 ) {
exit(200);
}
skipline(pnd);
} while ( strcmp(ifc.name, interface) );

bin = ifc.r_bytes + (lbin & ~0xffffffffULL);
bout = ifc.x_bytes + (lbout & ~0xffffffffULL);

if ( bin < lbin )
bin += (1ULL << 32);
if ( bout < lbout )
bout += (1ULL << 32);

if ( !first ) {
printf("%d %Lu %Lun", time(NULL), (bout-lbout)*8, (bin-lbin)*8);
fflush(stdout);
} else {
first = 0;
}

lbin = bin; lbout = bout;

fclose(pnd);

sleep(1);
}
}