Linux 下的 Shell

Refers:

https://www.cyberciti.biz/faq/how-to-change-shell-to-bash/

    sudo chsh -s /bin/bash $USERNAME
    sudo chsh -s /bin/bash user

查看用户的默认 Shell：

    $ grep user /etc/passwd
    user:x:1000:1000::/home/user:/bin/bash
    # 或者
    $ ps -p $$
    PID TTY          TIME CMD
    22572 pts/1    00:00:00 bash
    # 或者
    $ echo "$0"
    bash

查看系统可用 Shell：

    $ cat /etc/shells
    # /etc/shells: valid login shells
    /bin/sh
    /bin/bash
    /usr/bin/bash
    /bin/rbash
    /usr/bin/rbash
    /usr/bin/sh
    /bin/dash
    /usr/bin/dash
    /usr/bin/tmux
    /usr/bin/screen

通过 type -a bash 找到 bash 的所有位置。

`chsh`

更改当前用户 Shell

    chsh -s /bin/zsh
    echo $SHELL

列出所有 Shell

    chsh -l

`useradd`

新建用户（有家目录）

refer https://wiki.archlinux.org/title/Users_and_groups

    useradd -m example
    passwd example

`adduser`

adduser provides a high level interface for adding new users, and useradd provides a low level interface.

sed

https://www.gnu.org/software/sed/manual/sed.html

Quickly set up an SSH agent:

eval `ssh-agent` && ssh-add

from https://twitter.com/slicknet/status/1555246335883767808

awk

https://www.gnu.org/software/gawk/

使用 shellcheck 进行语法检查

检查文件权限数字

stat -c '%a' /file/path/
# 也可以是目录