How Linux looks at the current shell

1. Real-time view of the shell types used in the current process: recommended
The code is as follows:

PS | grep $$ | awk ' {print $4} '

(Note: $$ indicates the shell's process number)

2. The most common command to view the shell, but cannot reflect the current shell in real time

Copy CodeThe code is as follows:
$ echo $SHELL

3, more concise, but not all shell support

Copy CodeThe code is as follows:
$ echo $

4. The Shell matching search in environment variables

Copy CodeThe code is as follows:
env | grep SHELL

5, the password file in the shell matching search

Copy CodeThe code is as follows:
cat/etc/passwd | grep Muye

6. When using Ps-ef

Copy CodeThe code is as follows:
$ PS-EF | grep $$ | Grep-v grep | Grep-v PS

Note: Grep-v is reversed, as follows:

Copy CodeThe code is as follows:
Ps-ef | grep $$
Muye 4750 4745 0 15:47 pts/1 00:00:00 bash
Muye 5331 4750 0 16:51 pts/1 00:00:00 ps-ef
Muye 5332 4750 0 16:51 pts/1 00:00:00 grep--color=auto 4750

Remove the latter two

How Linux looks at the current shell