#include<unistd.h>
#include<sys/types.h>
#include<sys/wait.h>
#include<stdio.h>
#include<stdlib.h>
#include<fcntl.h>
#include<limits.h>
#define BUFSZ PIPE_BUF
void err_quit(char *msg)
{
perror(msg);
exit(EXIT_FAILURE);
}
int main(int argc, char *argv[])
{
FILE* fp;
int count;
char buf[BUFSZ];
char command[150];
if(argc != 2)
{
printf("USAGE: example <process name>\n");
exit(EXIT_SUCCESS);
}
else
sprintf(command, "ps -C %s|wc -l", argv[1] );
if((fp = popen(command,"r")) == NULL)
err_quit("popen");
if( (fgets(buf,BUFSZ,fp))!= NULL )
{
count = atoi(buf);
if((count - 1) == 0)
printf("%s not found\n",argv[1]);
else
printf("process : %s total is %d\n",argv[1],(count - 1));
}
pclose(fp);
exit(EXIT_SUCCESS);
}
使用方法：
gcc process.c
./a.out mon_agentd