cloud engineer
Here’s a regex using the pipe symbol as OR to allow only 6 possible values.
regex="efs-(00|04|08|12|16|20)00" |
regex="efs-(00|04|08|12|16|20)00"
Matches:
efs-0000 efs-0400 efs-0800 efs-1200 efs-1600 efs-2000 |
efs-0000 efs-0400 efs-0800 efs-1200 efs-1600 efs-2000
No matches:
efs-0100 efs-2200 efs-0600 efs-1400 efs-1800 efs-1110 111022 asdb023 2330asd 1200-efs 1205 abc |
efs-0100 efs-2200 efs-0600 efs-1400 efs-1800 efs-1110 111022 asdb023 2330asd 1200-efs 1205 abc
$var is compared with $regex to find a match. $var is any of the variables above.
if [[ $var != $regex ]]; then echo "Not a match" else echo "It's a match" fi |
if [[ $var != $regex ]]; then echo "Not a match" else echo "It's a match" fi
Regex is really cool. You can do amazing things with it, but if you’re starting new, it’s quite daunting task. If you ever find one that works, you better hang on to it for dear life. Here’s one that I know is working. It reads data from a file, and compares and matches a variable to a certain pattern. In the example below, the variable I’m searching for, must contain a string with the following characters “server-w.” They also must be followed by at least one number or a set of numbers.
cat filename | while read LINE; do if [[ $LINE =~ server-w-*.[0-9] ]]; then echo "Do not backup $LINE" else echo "Backup $LINE" fi done |
cat filename | while read LINE; do if [[ $LINE =~ server-w-*.[0-9] ]]; then echo "Do not backup $LINE" else echo "Backup $LINE" fi done
If you need help with Regex, check out a couple of sites below that allows you to test your regex skills. Regex and RegExr.