Q. How can you test if a file is writable under UNIX / Linux bash shell scripting?
A. You can easily test if a file is writable or noting test command under UNIX / Linux.
The -w option
The -w option is used to test if a FILE exists and write permission is granted or not. It returns true if a file is writable.
General syntax is as follows:
[ -w filename ] && echo "Writable" || echo "Not Writable"
test -w filename && echo "Writable" || echo "Not Writable"
Here is a sample shell script:
#!/bin/bash FILE="$1" [ $# -eq 0 ] && exit 1 if [ -w "$FILE" ] then echo "Write permission is granted on $FILE" else echo "Write permission is NOT granted on $FILE" fi