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Diffstat (limited to 'tcl/doc/if.n')
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diff --git a/tcl/doc/if.n b/tcl/doc/if.n new file mode 100644 index 00000000000..98c314569ce --- /dev/null +++ b/tcl/doc/if.n @@ -0,0 +1,43 @@ +'\" +'\" Copyright (c) 1993 The Regents of the University of California. +'\" Copyright (c) 1994-1996 Sun Microsystems, Inc. +'\" +'\" See the file "license.terms" for information on usage and redistribution +'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. +'\" +'\" RCS: @(#) $Id$ +'\" +.so man.macros +.TH if n "" Tcl "Tcl Built-In Commands" +.BS +'\" Note: do not modify the .SH NAME line immediately below! +.SH NAME +if \- Execute scripts conditionally +.SH SYNOPSIS +\fBif \fIexpr1 \fR?\fBthen\fR? \fIbody1 \fBelseif \fIexpr2 \fR?\fBthen\fR? \fIbody2\fR \fBelseif\fR ... ?\fBelse\fR? ?\fIbodyN\fR? +.BE + +.SH DESCRIPTION +.PP +The \fIif\fR command evaluates \fIexpr1\fR as an expression (in the +same way that \fBexpr\fR 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 \fBtrue\fR or \fByes\fR +for true and \fBfalse\fR or \fBno\fR for false); +if it is true then \fIbody1\fR is executed by passing it to the +Tcl interpreter. +Otherwise \fIexpr2\fR is evaluated as an expression and if it is true +then \fBbody2\fR is executed, and so on. +If none of the expressions evaluates to true then \fIbodyN\fR is +executed. +The \fBthen\fR and \fBelse\fR arguments are optional +``noise words'' to make the command easier to read. +There may be any number of \fBelseif\fR clauses, including zero. +\fIBodyN\fR may also be omitted as long as \fBelse\fR 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 \fIbodyN\fR. + +.SH KEYWORDS +boolean, conditional, else, false, if, true |