help clip file extension in bash

mike acker · 01-19-2021, 12:22 PM

any hints / help will be appreciated!!

I'm working in a bash script

I have a file name (e.g.) message.txt.asc

I need to get the plaintext name: message.txt

For some reason I cant get the parameter expansion to work:

TXTNM="${$1%.asc}"

this should result in name for the plaintext as message.txt

i think I've got it now:

TXTNM="${1%.*}"

but I can't see where I've gone wrong

Turbocapitalist · 01-19-2021, 12:32 PM

You are very close. Check the syntax again.

Code:

TXTNM="${1%.asc}"

mike acker · 01-19-2021, 02:55 PM

Quote:

Originally Posted by Turbocapitalist

You are very close. Check the syntax again.

Code:

TXTNM="${1%.asc}"

thanks; I got it working now!
I always have trouble with the quotes and the $

MadeInGermany · 01-21-2021, 12:32 AM

Keep in mind that $var is short for ${var}
The quotes protect against field splitting and filename generation after expansion.
An exercise:

Code:

var1="two words"
var2="*"
printf "%s\n" "${var1} ${var2}"
printf "%s\n" "${var1}" "${var2}"

See what happens if you remove the quotes.