Please explain below PS1 variable

Shell Programming and Scripting
1

please tell me what is "!" mean in below value of PS1 variable

PS1='($PWD) !>'

Thanks Sunny

2 
PS1='($PWD) !>'

In this context the ! outputs the current line number in the shell history file.
The ">" is just a character and plays no active part.

Type "history" to see the correlation of the line numbers.
Notice that the line number is one higher than expected because executing the "PS1" statement counts as a command.

3

Thanks Buddy!:b:

4

you can do a lot more with PS1. refer Chapter 6: Linux PS1 Prompt Examples