Text-only	Table of Contents (frame/ no frame)
(17) Conditional Tests (contd.)

$variable -eq number

True if $variable, interpreted as a number, is equal to number.

$variable -ne number

True if $variable, interpreted as a number, is not equal to number.
Similarly, -lt = less than, -le = less than or equal, -gt = greater than, -ge = greater than or equal

$variable = pattern

True if $variable matches pattern. If pattern contains no wildcards, then this is just an exact text match. The same wildcards as used for filename matching are used.

The pattern must not be quoted. Since [[...]] is internal to the shell, the pattern in this case is treated differently and not filename-expanded as an external command would require.

file1 -nt file2

True if file1 is newer than file2.
Similarly -ot = older than

file1 -ef file2

true if file1 is effectively the same as file2, after following symlinks and hard links.

conditional -a conditional, conditional -o conditional

AND and OR syntax for test and [

conditional && conditional, conditional || conditional

AND and OR syntax for [[ ... ]]

Examples:

if [[  -x /usr/local/bin/lserve && \
       -w /var/logs/lserve.log ]]; then
   /usr/local/bin/lserve >> /var/logs/lserve.log &
fi

pwent=`grep '^richard:' /etc/passwd`
if [ -z "$pwent" ]; then
   echo richard not found
fi