main함수 세번째 인자

main에 세번째 인자는 환경변수를 출력사고자 할 때 사용된다.

환경변수 출력
int main(int argc, char **argv, char *envp[])
{
    int i;

    i = 0;
    for (i = 0; envp[i]; i++)
    {
        printf("%s\n", envp[i]);
    }
    return (0);
}

 

<출력 결과>

USER=namgyupark
SECURITYSESSIONID=186ba
COMMAND_MODE=unix2003
__CFBundleIdentifier=com.microsoft.VSCode
PATH=/opt/homebrew/bin:/opt/homebrew/bin:/Users/namgyupark/opt/anaconda3/bin:/Users/namgyupark/opt/anaconda3/condabin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
HOME=/Users/namgyupark
SHELL=/bin/zsh
LaunchInstanceID=8869CBD4-9293-4725-A539-F4D56D9FA5D3
__CF_USER_TEXT_ENCODING=0x1F5:0x3:0x33
XPC_SERVICE_NAME=0
SSH_AUTH_SOCK=/private/tmp/com.apple.launchd.mdOjbRteog/Listeners
XPC_FLAGS=0x0
LOGNAME=namgyupark
TMPDIR=/var/folders/v7/5vskt34x7mq5y5dwfcmjr71w0000gn/T/
ORIGINAL_XDG_CURRENT_DESKTOP=undefined
SHLVL=1
PWD=/Users/namgyupark/42/42seoul_minishell/test
OLDPWD=/Users/namgyupark/42/42seoul_minishell
CONDA_EXE=/Users/namgyupark/opt/anaconda3/bin/conda
CONDA_PYTHON_EXE=/Users/namgyupark/opt/anaconda3/bin/python
CONDA_SHLVL=1
CONDA_PREFIX=/Users/namgyupark/opt/anaconda3
CONDA_DEFAULT_ENV=base
CONDA_PROMPT_MODIFIER=(base) 
TERM_PROGRAM=vscode
TERM_PROGRAM_VERSION=1.56.2
LANG=ko_KR.UTF-8
COLORTERM=truecolor
VSCODE_GIT_IPC_HANDLE=/var/folders/v7/5vskt34x7mq5y5dwfcmjr71w0000gn/T/vscode-git-934a20f384.sock
GIT_ASKPASS=/Users/namgyupark/Desktop/Visual Studio Code.app/Contents/Resources/app/extensions/git/dist/askpass.sh
VSCODE_GIT_ASKPASS_NODE=/Users/namgyupark/Desktop/Visual Studio Code.app/Contents/Frameworks/Code Helper (Renderer).app/Contents/MacOS/Code Helper (Renderer)
VSCODE_GIT_ASKPASS_MAIN=/Users/namgyupark/Desktop/Visual Studio Code.app/Contents/Resources/app/extensions/git/dist/askpass-main.js
TERM=xterm-256color
_CE_M=
_CE_CONDA=
_=/Users/namgyupark/42/42seoul_minishell/test/./a.out
(base) namgyupark@NAMGYUui-MacBookAir test %