When we execute the command echo $COLUMNS
, where is COLUMNS
located? I thought it was just an environment variable, but it is not displayed in env
.
1 Answer
COLUMNS
is a shell variable, not an environment variable. Therefore, you will not find it when you use env
. If you are not sure what the differences between a shell variable and an environment variable are, take a look at Environment variable vs Shell variable, what's the difference?.
According to https://askubuntu.com/a/275972/15003, you can find COLUMNS
if you run
( set -o posix; set ) | grep COLUMNS
which, on my machine, gives
COLUMNS=206
-
1