tcl7.6 User Commands - case
NAME
case - Evaluate one of several scripts, depending on a given
value
SYNOPSIS
case string ?in? patList body ?patList body ...?
case string ?in? {patList body ?patList body ...?}
DESCRIPTION
Note: the case command is obsolete and is supported only for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 con-
tain any of the wild-cards 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 argu-
ments. The first uses a separate argument for each of the
patterns and commands; this form is convenient if substitu-
tions 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.
KEYWORDS
case, match, regular expression