php 执行系统命令的方法

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>

int main(int argc,char * argv[])
{
    uid_t uid,euid;
    char cmd[1024]="chmod -r 777 ";
    uid =getuid();
    euid = geteuid();


    //printf("param %s\n",strcat(cmd,argv[1]));
    //exit(0);
    //printf("uid:%un. eudi=%un\n",getuid(),geteuid());

    if(setreuid(euid,uid))
        perror("setreuid");

    //printf("uid:%un. eudi=%un\n",getuid(),geteuid());    

system(strcat(cmd,argv[1]));
    return 0;

}

$chmod_line = dirname(__file__)."/phpchmod ./dest_dir/";
system($chmod_line);