fix command for #Check if a variable is null

This commit is contained in:
bonnie ng 2024-08-29 18:14:01 +00:00
parent 7cfb4e286c
commit 6479b26656

View File

@ -1052,9 +1052,10 @@ else
echo >&2 "Fatal error. This script requires mydir."
fi
# if variable is null
if [ ! -s "$myvariable" ]; then echo -e "variable is null!" ; fi
# True of the length if "STRING" is zero.
# Check if a variable is null
if [ -z "$var" ]; then echo "NULL"; else echo "Not NULL"; fi
# or
[ -z "$var" ] && echo "NULL"
# Using test command (same as []), to test if the length of variable is nonzero
test -n "$myvariable" && echo myvariable is "$myvariable" || echo myvariable is not set