用C语言打印出当前pwd的值

#include<stdio.h>
int main(int argc ,char *argv[],char *envp[])
{    
    printf("### ARGC ###\n%d\n",argc);
    printf("### ARGV ###\n");
    while(*argv)
        printf("%s\n",*(argv++));
    printf("### ENVP ###\n");
    while(!(((*envp)[0]=='P')&&((*envp)[1]=='W')&&((*envp)[2]=='D')))
        *(envp++);
        printf("%s\n",*envp);
    return 0;
}

程序运行结果！
1 ### ARGC ###
2 1
3 ### ARGV ###
4 ./2
5 ### ENVP ###
6 PWD=/home/wangguolong/test/C_language_pointer/process