if(n) Tcl if(n)
_________________________________________________________________
NAME
if - Execute scripts conditionally
SYNOPSIS
if expr1 ?then? body1 elseif expr2 ?then? body2 elseif ...
?else? ?bodyN?
_________________________________________________________________
DESCRIPTION
The if command evaluates expr1 as an expression (in the same
way that expr evaluates its argument). The value of the
expression must be a boolean (a numeric value, where 0 is
false and anything is true, or a string value such as true
or yes for true and false or no for false); if it is true
then body1 is executed by passing it to the Tcl interpreter.
Otherwise expr2 is evaluated as an expression and if it is
true then body2 is executed, and so on. If none of the
expressions evaluates to true then bodyN is executed. The
then and else arguments are optional ``noise words'' to make
the command easier to read. There may be any number of
elseif clauses, including zero. BodyN may also be omitted
as long as else is omitted too. The return value from the
command is the result of the body script that was executed,
or an empty string if none of the expressions was non-zero
and there was no bodyN.
KEYWORDS
boolean, conditional, else, false, if, true
Page 1 (printed 2/19/99)
