C程序打印环境变量

#include 

int main(void)
{ 
	extern char **environ; 
	int i; 
	for(i=0; environ[i]!=NULL; i++) 
		printf("%sn", environ[i]); 
	return 0;

}

输出：

pcl@V3:~/work/test/asm$ env
SHELL=/bin/bash
LANGUAGE=zh_CN:zh
PWD=/home/pcl/work/test/asm
LOGNAME=pcl
XDG_SESSION_TYPE=tty
MOTD_SHOWN=pam
HOME=/home/pcl
LANG=zh_CN.UTF-8
TERM=xterm
LESSOPEN=| /usr/bin/lesspipe %s
USER=pcl
DISPLAY=localhost:12.0
SHLVL=1
XDG_SESSION_ID=245
XDG_RUNTIME_DIR=/run/user/1000
XDG_DATA_DIRS=/usr/local/share:/usr/share:/var/lib/snapd/desktop
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
OLDPWD=/home/pcl
_=/usr/bin/env

参考：