C语言 Linux环境变量

/*

*@author cody

*@date 2014-08-12

*@description 

*/



/*

extern char **environ  //environment values



#include <stdlib.h>

char *getenv(const char *name);

int setenv(const char *name,const char *value,int rewrite); // set enviroment if exists rewrite - 0 do  not rewrite not 0 rewrite

void unsetenv(const char *name); //delete env by name

*/



#include <stdio.h>

#include <stdlib.h>



void environment(){

    extern char **environ;

    int i;

    for(i = 0;environ[i] != NULL;i ++){

        printf("%s\n",environ[i] );

    }

}



void getPath(){



    char *path = getenv("PATH");

    printf("PATH = %s\n",path );



    setenv("PATH","HELLO",1);

    path = getenv("PATH");

    printf("PATH = %s\n",path );





}



int main(int argc, char const *argv[])

{

    

    //environment();

    getPath();

    return 0;

}