Need help in print System variables: $PS1, $LINES, $COLUMNS

[liembt]

Hi!

I'm newbie in Linux & Scripting. I have a script file:
#
# print prompt settings
#
clear
echo "Prompt Settings: $PS1"
echo "Number of lines on the screen: $LINES"
echo "Number of columns on the screen: $COLUMNS"
exit 0

But I don't know I can't print out the values of $PS1, $LINES, $COLUMNS.

Please help me
Thank you.

[markcole]

Look up a "scripting howto" or something similar such as this.

[lomcevak]

I assume you ran the script with either:

./script.sh

or

sh script.sh

Problem here is that a child process is created to run the script and those system variables don't exist in child processes since they're not needed. You'd have to run it in the current shell process which is done with:

source script.sh

WARNING: You're 'exit 0' command will log you off. Better to comment that out first.

[liembt]

I assume you ran the script with either:

./script.sh

or

sh script.sh

Problem here is that a child process is created to run the script and those system variables don't exist in child processes since they're not needed. You'd have to run it in the current shell process which is done with:

source script.sh

WARNING: You're 'exit 0' command will log you off. Better to comment that out first.

Thanks lomcevak very much! I run the code successful use your instructions.
Thaks markcole for a good book.