case -- Command

Execute commands conditionally according to pattern
case token in [pattern [|pattern] ...) sequence ;;] ... esac

case is a construct that used  by the shell.  It tells the shell to execute
commands conditionally,  according to a pattern.  It  tests the given token
successively against  each pattern, in  the order given.   It then executes
the commands  in the sequence corresponding to  the first matching pattern.
Optional `|' clauses  specify additional patterns corresponding to a single
sequence. If  no pattern matches the token, the  case construct executes no
commands.

Each pattern can  include text characters (which match themselves), special
characters `?' (which matches  any character except newline) and `*' (which
matches  any sequence  of  non-newline characters),  and character  classes
enclosed in  brackets `[  ]'; ranges  of characters within  a class  may be
separated by `-'.   In particular, the last pattern in  a case construct is
often `*', which will match any token.

The shell executes case directly.

Example

The following example prints a string in response to a command-line option:

    case $1 in
        FOO)    echo "This is option FOO";;
        BAR)    echo "This is option BAR";;
        BAZ)    echo "This is option BAZ";;
        *)  echo "An asterisk marks the default option";;
    esac

See Also

commands,
ksh,
sh

© 2012 by Stephen A. Ness