The shell's case
statement (Section
35.10) has some advantages over the test
command (Section
35.26) — for instance, case can do
pattern matching. But test
has the -a and
-o "and" and "or" operators; those don't seem easy to do
with case. And test isn't built in to some older shells, so using case may be faster.
Here's a way to test two things with one case statement. It won't solve all your problems. If you think carefully about the possible values the variables you're testing can have, though, this might do the trick. Use a separator (delimiter) character between the two variables.
In the example below, I've picked a slash (/). You could use almost any character that isn't used in
case pattern matching (Section 35.11) and that won't be stored
in either $# or $1. The case below tests the
command-line arguments of a script:
case "$#/$1" in 1/-f) redodb=yes ;; 0/) ;; *) echo "Usage: $0 [-f]" 1>&2; exit 1 ;; esac
If there's one argument ($# is 1) and the argument ($1) is exactly -f, the first
pattern matches, and the redodb variable is set. If there's
no argument, $# will be 0 and $1 will
be empty, so the second pattern matches. Otherwise, something is wrong; the
third pattern matches, the script prints an error and exits.
Of course, you can do a lot more this way than just testing command-line arguments.
— JP