case(3Tcl) case(3Tcl)
case - Evaluate one of several scripts, depending on a given value
case string ?in? patList body ?patList body ...?
case string ?in? {patList body ?patList body ...?}
Note: the case command is obsolete and is supported only for backward
compatibility. At some point in the future it may be removed entirely.
You should use the switch command instead.
The case command matches string against each of the patList arguments in
order. Each patList argument is a list of one or more patterns. If any
of these patterns matches string then case evaluates the following body
argument by passing it recursively to the Tcl interpreter and returns the
result of that evaluation. Each patList argument consists of a single
pattern or list of patterns. Each pattern may contain any of the wildcards
described under string match. If a patList argument is default,
the corresponding body will be evaluated if no patList matches string.
If no patList argument matches string and no default is given, then the
case command returns an empty string.
Two syntaxes are provided for the patList and body arguments. The first
uses a separate argument for each of the patterns and commands; this form
is convenient if substitutions are desired on some of the patterns or
commands. The second form places all of the patterns and commands
together into a single argument; the argument must have proper list
structure, with the elements of the list being the patterns and commands.
The second form makes it easy to construct multi-line case commands,
since the braces around the whole list make it unnecessary to include a
backslash at the end of each line. Since the patList arguments are in
braces in the second form, no command or variable substitutions are
performed on them; this makes the behavior of the second form different
than the first form in some cases.
case, match, regular expression
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