o="this is a test"
echo ${foo:+bar}
bar
${foo:?"error message"} If $foo exists and is not null, ret... value. If it doesn't exist or is null, print the error message. If no error message is given, print parameter null or not set. Note: In a non-interactive... In an interactive shell, this will just print the error message. export foo="one" for i in foo bar ba
en
echo "Usage: `basename $0` filename" >&2
# Error message to stderr.
exit $E_NOARGS
# Returns 65 as exit status of script (error code).
fi
filename=$1
if [ ! -f "$filename... .
then
echo "File $filename not found!" >&2 # Error message to stderr.
exit $E_NOTFOUND
fi
if
