[SOLVED] Unsetting Variables & Terminator Placement

shirase · 12-05-2023, 12:15 PM

If I want to temporarily change the IFS like in the example here:

Code:

while IFS='' read -r var ; do cmd ; done ;

Then does it matter which of these are used?
Do they do anything different from each other?

Code:

env -u IFS ; cmd ;
env -u IFS cmd ;
IFS='' ; cmd ;
IFS= ; cmd ;
IFS='' cmd ;
IFS= cmd ;
OLDIFS=IFS ; unset IFS ; cmd ; set IFS=OLDIFS ; unset OLDIFS ;
OLDIFS=IFS ; unset IFS cmd ; set IFS=OLDIFS ; unset OLDIFS ;

pan64 · 12-05-2023, 12:22 PM

yes, they are not all the same, but some of them are identical.
You might want to set -xv before executing these commands to see the differences.
Also you can use different cmd -s to see how they react on those settings (like echo "'$IFS'")