how to use "joker" or wildcard in string patterns (spaces separated words) in a bash case statement?

Question

How to use bash's "case" statement for "very specific" string patterns (multiple words, including spaces) ?

The problem is: I receive a multi-word String from a function which is pretty specific, including a version number. The version number now changes from time to time. Instead of adding more and more specific string patterns to my case statement, I would like to use a joker (or whatever the word for this is, like "Ubuntu 16.04.? LTS" or "Ubuntu 16.04.* LTS" . However, I didn't find any solution to this yet.

See this shell script I used so far:

    .
    .
    .
    case "${OS}" in
    "SUSE Linux Enterprise Server 11 SP4")
        echo "SLES11 detected."
        ;;
    "Ubuntu 16.04.3 LTS" | "Ubuntu 16.04.4 LTS"     )
        echo "UBUNTU16 detected."
        ;;
    "CentOS Linux 7 (Core)")
        echo "CENTOS7 detected."
        ;;
    *)
        echo "Unknown OS detected. Quitting for safety reasons."
        exit -1
        ;;
    .
    .
    .

PS: i read the "pattern" part of the manual and tested some variations of "jokers", but it always failed, since i just forgot to simply drop the doublequotes and to escape the whitespaces. duh! — Axel Werner, Apr 03 '18 at 14:17
I think the term you might be thinking of is "wildcard" (for joker) — Jeff Schaller, Jul 01 '18 at 13:36

jesse_b · Accepted Answer · 2018-04-03T14:15:14.603

4

You can use patterns in case statements, however you can't quote them so you have to escape whitespace.

case ${OS} in
"SUSE Linux Enterprise Server 11 SP4")
    echo "SLES11 detected."
    ;;
Ubuntu\ 16.04.[3-4]\ LTS)
    echo "UBUNTU16 detected."
    ;;
"CentOS Linux 7 (Core)")
    echo "CENTOS7 detected."
    ;;
*)
    echo "Unknown OS detected. Quitting for safety reasons."
    exit -1
    ;;

edited Apr 03 '18 at 14:15

answered Apr 03 '18 at 14:00

jesse_b

35,934
12
91
140

@StephenKitt updated. – jesse_b Apr 03 '18 at 14:08
doh!! Escaping the spaces is the solution . sometimes im blind for the easiest solution. thanks. So this did the trick for me: ` Ubuntu\ 16.04.*\ LTS )` – Axel Werner Apr 03 '18 at 14:09
5

You could also quote the literal parts but not the wildcards: `'Ubuntu 16'*)` -- I find that to be more readable than backslashes – glenn jackman Apr 03 '18 at 14:55

how to use "joker" or wildcard in string patterns (spaces separated words) in a bash case statement?

1 Answers1