Question

I am writing an AWK script that starts an infinite loop – hence in the script I validate presence of file in a specified path if so I would exit from the infinite loop :

while ( ("ls -l /tmp/STOP" |& getline var4) > 0) {
        exit 0
}
close("ls -l /tmp/STOP")

The issue is that I get standard error during the run time when the file is not there:

ls: /tmp/STOP: No such file or directory

How can we avoid this standard error message on the console?

Answer 1

Try redirecting the error stream to /dev/null:

while ( ("ls -l /tmp/STOP 2>/dev/null" |& getline var4) > 0) {
    exit 0
}
close("ls -l /tmp/STOP")