APUE练习

主要用来练习Linux下的C编程

/*
 ============================================================================
 Name        : Process003.c
 Author      : Chunyang Guo
 Version     :
 Copyright   : Your copyright notice
 Description : Hello World in C, Ansi-style
 ============================================================================
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
//popen与system的不同之处就是它采用管道进行工作
//打开后就像普通文件一样进行操作
int main(void) {
    puts("!!!Hello World!!!"); /* prints !!!Hello World!!! */
//  system("ps aux");
//  sleep(10);
    FILE *read_fp;
    char buffer[BUFSIZ + 1];
    int chars_read;
    memset(buffer, 0x00, sizeof(buffer));
    read_fp = popen("ps aux", "r");
    if (read_fp == NULL){
        exit(EXIT_FAILURE);
    }
    //chars_read = fread(buffer, sizeof(char), BUFSIZ, read_fp);
    while((chars_read = fread(buffer, sizeof(char), BUFSIZ, read_fp) ) > 0){
        buffer[chars_read - 1] = 0;
        printf("%s", buffer);
    }
    pclose(read_fp);
    return EXIT_SUCCESS;
}