The realization method of acquiring network traffic under Linux __linux

The data is read only through/proc/net/dev. Reproduced

#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-A;

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

interface = Argv[1];

i = 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 {
i = 0;
}

Lbin = bin; Lbout = bout;

Fclose (PND);

Sleep (1);
}
}