Find number of threads and Processes in a C Program

Question

Hi, how do i find the number of total threads and processes in this C program?

Thanks

#include <stdio.h>

#include <unistd.h>

#include <pathread.h>

Int main()

{ int I;

For(i=0; i<5; i++)

{fork()

Thread_create(&tid, NULL, hello, NULL); }

Return 0; }

Int hello()

 {  void * x  }

Answer 1

The simplest is to parse the output of commands using popen.

The following:

#include <assert.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

void parse_output(char *buf, size_t bufsize, const char cmd[])

{

assert(buf != NULL);

assert(cmd != NULL);

FILE *fp;

// add dynamic allocation herememset(buf, 0, bufsize);

if ((fp = popen(cmd, "r")) == NULL) {

printf("Error opening pipe!\n");

exit(-__LINE__);

}

// worst speed ever. And strlen is called twice...while (fgets(&buf[strlen(buf)], bufsize - strlen(buf), fp) != NULL);

if(pclose(fp)) {

printf("Command not found or exited with error status\n");

exit(-__LINE__);

}

}

int main() {

char buf[256];

long num;

parse_output(buf, sizeof(buf), "ps -A --no-headers | wc -l");

if (sscanf(buf, "%ld", &num) != 1) {

exit(-__LINE__);

}

printf("Number of processes: %ld\n", num);

parse_output(buf, sizeof(buf), "ps -AL --no-headers | wc -l");

if (sscanf(buf, "%ld", &num) != 1) {

exit(-__LINE__);

}

printf("Number of processes including tasks: %ld\n", num);

}

will output on my system:

$ gcc 1.c && ./a.out

Number of processes: 241

Number of processes includeing tasks: 867