Issue with Single Quotes and Double Quotes for prompt PS1

Shell Programming and Scripting
1

Hi,

Trying to change the prompt. I have the following code.

export PS1='
[$PWD]
<${USER}@`hostname -s`>$ '

The hostname is not displayed

[/users/home/abc]
<abc@`hostname -s`>$ uname -a
AIX xyz 1 6 00F736154C00

[/users/home/adcwl4h]
<adcwl4h@`hostname -s`>$

If I use double quotes, then the hostname is printed properly but the path on the screen display does not change even when I change the directory. I'm using korn shell in AIX.

So...
1) what is the diff b/w single and double quote
2) what is the correct code to display my path, user and hostname as I'm trying with the above code.

Appreciate your help.

2

Single quotes turn of meta meanings entirely, so I prefer them, generally. When setting PS1:

  • anything for evaluation later must be in single quotes, like $PWD or an effective id or date call.
  • Things you can set at login time, like login id, tty or host name, can be barefoot or in double quotes.
1 Like
3

That means

export PS1='
[$PWD]
<${USER}@'`hostname -s`'>$ '
1 Like
4

If user and hostname are not dynamic, why not evaluate them once?

export PS1='
[$PWD]
<'"$USER@`hostname -s`>"'$ '