Linux common shell

Linux common shell

Source: https://www.cnblogs.com/leilong/p/9206487.html

　Different shell have different functions, shell also determines the default shell in Linux is / bin / bash, popular shell there is ash, bash, ksh, csh, zsh, etc., of shell has its own different characteristics and uses.

bash
Most Linux systems use default shell, bash shell is a free version of the Bourne shell, it is the first Unix shell, bash also has a feature, can help command
to view the help. It includes features may encompass almost the shell has the function, it is generally as a shell script will specify its execution path.

csh
C shell using a "Class C" syntax, csh is a shell having a C-style, it has 52 internal command, it is huge. Currently not much use,
have been replaced by / bin / tcsh.

ksh
same shell Korn shell syntax with Bourne, along with the ease of use features of the C shell. Many installation scripts use ksh, ksh has 42 internal command, there are certain restrictive compared to the bash.

tcsh
tcsh is an enhanced version of csh, fully compatible with the C shell.

sh
is a shortcut, it has been replaced by / bin / bash.

nologin
means that the user can not log in

zsh
is currently one of the largest in the Linux shell: zsh. It has 84 internal command is also more complicated. Under normal circumstances, do not use
the shell.

Linux often have several pre shell, its type is stored in / etc / shells using cat /etc/shellsto view, to switch to the shell, you only need to enter the name of the shell

To view the current run of the shell can typeecho $0

/ Etc / passwd save each user's login information, which has a shell type they are using Login