linux c之main(int argc,char *argv[],char *envp[])参数意义

1、问题

我们常见的int main(int argc, char *argv[], char *envp[]) 各个参数的意义。

 

2、代码

#include<stdio.h>  

#include<unistd.h>

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

{  

printf("argc ###\n%d\n",argc);  

puts("argc end *****************************");  

while (*argv) {  

printf("%s\n", *(argv++));  

}  

puts("argv end ~***************************");  

while (*envp) {  

printf("%s\n", *(envp++));  

}  

return 0;  

}

 

3、结果展示

chenyu@chenyu:~/Desktop/linux$ gcc -g argv.c -o argv  

chenyu@chenyu:~/Desktop/linux$ ./argv   

argc ###  

1  

argc end *****************************  

./argv  

argv end ~***************************  

XDG_VTNR=7  

LC_PAPER=en_US.UTF-8  

NDK=/home/chenyu/Android_dev/android-ndk-r10e  

LC_ADDRESS=en_US.UTF-8  

XDG_SESSION_ID=c2  

XDG_GREETER_DATA_DIR=/var/lib/lightdm-data/chenyu  

LC_MONETARY=en_US.UTF-8  

CLUTTER_IM_MODULE=xim  

GPG_AGENT_INFO=/home/chenyu/.gnupg/S.gpg-agent:0:1  

TERM=xterm-256color  

VTE_VERSION=4205  

SHELL=/bin/bash  

QT_LINUX_ACCESSIBILITY_ALWAYS_ON=1  

WINDOWID=90190046  

LC_NUMERIC=en_US.UTF-8  

UPSTART_SESSION=unix:abstract=/com/ubuntu/upstart-session/1000/1406  

GNOME_KEYRING_CONTROL=  

GTK_MODULES=gail:atk-bridge:unity-gtk-module  

NO_PROXY=localhost,127.0.0.0/8,::1  

http_proxy=http://199.200.72.4:8080/  

USER=chenyu  

QT_ACCESSIBILITY=1  

LC_TELEPHONE=en_US.UTF-8  

XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session0  

XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0  

SSH_AUTH_SOCK=/run/user/1000/keyring/ssh  

ftp_proxy=ftp://199.200.72.4:8080/  

DEFAULTS_PATH=/usr/share/gconf/ubuntu.default.path  

XDG_CONFIG_DIRS=/etc/xdg/xdg-ubuntu:/usr/share/upstart/xdg:/etc/xdg  

all_proxy=socks://199.200.72.4:8080/  

ALL_PROXY=socks://199.200.72.4:8080/  

DESKTOP_SESSION=ubuntu  

PATH=/home/chenyu/Android_dev/sdk/tools:/home/chenyu/Android_dev/sdk/platform-tools:/home/chenyu/Android_dev/sdk/build-tools/23.0.2:/home/chenyu/Android_dev/android-ndk-r10e:/home/chenyu/Android_dev/jdk1.8.0_11/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin

QT_IM_MODULE=fcitx  

QT_QPA_PLATFORMTHEME=appmenu-qt5  

LC_IDENTIFICATION=en_US.UTF-8  

XDG_SESSION_TYPE=x11  

PWD=/home/chenyu/Desktop/linux  

JOB=gnome-session  

socks_proxy=socks://199.200.72.4:8080/  

XMODIFIERS=@im=fcitx  

JAVA_HOME=/home/chenyu/Android_dev/jdk1.8.0_11  

GNOME_KEYRING_PID=  

LANG=en_US.UTF-8  

GDM_LANG=en_US  

MANDATORY_PATH=/usr/share/gconf/ubuntu.mandatory.path  

LC_MEASUREMENT=en_US.UTF-8  

COMPIZ_CONFIG_PROFILE=ubuntu  

IM_CONFIG_PHASE=1  

PAPERSIZE=letter  

https_proxy=https://199.200.72.4:8080/  

GDMSESSION=ubuntu  

SESSIONTYPE=gnome-session  

GTK2_MODULES=overlay-scrollbar  

SHLVL=1  

HOME=/home/chenyu  

XDG_SEAT=seat0  

LANGUAGE=en_US:en  

no_proxy=localhost,127.0.0.0/8,::1  

GNOME_DESKTOP_SESSION_ID=this-is-deprecated  

UPSTART_INSTANCE=  

UPSTART_EVENTS=started starting  

XDG_SESSION_DESKTOP=ubuntu  

LOGNAME=chenyu  

XDG_DATA_DIRS=/usr/share/ubuntu:/usr/share/gnome:/usr/local/share/:/usr/share/:/var/lib/snapd/desktop  

CLASSPATH=.:/home/chenyu/Android_dev/jdk1.8.0_11/lib:/home/chenyu/Android_dev/jdk1.8.0_11/jre/lib  

QT4_IM_MODULE=fcitx  

DBUS_SESSION_BUS_ADDRESS=unix:abstract=/tmp/dbus-l8HM2dsSoK  

LESSOPEN=| /usr/bin/lesspipe %s  

INSTANCE=Unity  

UPSTART_JOB=unity-settings-daemon  

XDG_RUNTIME_DIR=/run/user/1000  

DISPLAY=:0  

XDG_CURRENT_DESKTOP=Unity  

GTK_IM_MODULE=fcitx  

LESSCLOSE=/usr/bin/lesspipe %s %s  

LC_TIME=en_US.UTF-8  

LC_NAME=en_US.UTF-8  

XAUTHORITY=/home/chenyu/.Xauthority  

OLDPWD=/home/chenyu/Desktop  

_=./argv

 

4、总结：

argc是命令行参数个数，char *argv[]是指所有命令行参数，char *envp[]是环境变量。

 

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