| 1 | '\" |
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| 2 | '\" Copyright (c) 1993 The Regents of the University of California. |
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| 3 | '\" Copyright (c) 1994-1996 Sun Microsystems, Inc. |
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| 4 | '\" |
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| 5 | '\" See the file "license.terms" for information on usage and redistribution |
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| 6 | '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. |
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| 7 | '\" |
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| 8 | '\" RCS: @(#) $Id: set.n,v 1.9 2007/12/13 15:22:33 dgp Exp $ |
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| 9 | '\" |
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| 10 | .so man.macros |
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| 11 | .TH set n "" Tcl "Tcl Built-In Commands" |
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| 12 | .BS |
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| 13 | '\" Note: do not modify the .SH NAME line immediately below! |
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| 14 | .SH NAME |
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| 15 | set \- Read and write variables |
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| 16 | .SH SYNOPSIS |
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| 17 | \fBset \fIvarName \fR?\fIvalue\fR? |
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| 18 | .BE |
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| 19 | .SH DESCRIPTION |
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| 20 | .PP |
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| 21 | Returns the value of variable \fIvarName\fR. |
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| 22 | If \fIvalue\fR is specified, then set |
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| 23 | the value of \fIvarName\fR to \fIvalue\fR, creating a new variable |
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| 24 | if one does not already exist, and return its value. |
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| 25 | If \fIvarName\fR contains an open parenthesis and ends with a |
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| 26 | close parenthesis, then it refers to an array element: the characters |
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| 27 | before the first open parenthesis are the name of the array, |
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| 28 | and the characters between the parentheses are the index within the array. |
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| 29 | Otherwise \fIvarName\fR refers to a scalar variable. |
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| 30 | .PP |
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| 31 | If \fIvarName\fR includes namespace qualifiers |
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| 32 | (in the array name if it refers to an array element), or if \fIvarName\fR |
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| 33 | is unqualified (does not include the names of any containing namespaces) |
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| 34 | but no procedure is active, |
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| 35 | \fIvarName\fR refers to a namespace variable |
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| 36 | resolved according to the rules described under \fBNAME RESOLUTION\fR in |
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| 37 | the \fBnamespace\fR manual page. |
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| 38 | .PP |
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| 39 | If a procedure is active and \fIvarName\fR is unqualified, then |
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| 40 | \fIvarName\fR refers to a parameter or local variable of the procedure, |
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| 41 | unless \fIvarName\fR was declared to resolve differently through one of the |
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| 42 | \fBglobal\fR, \fBvariable\fR or \fBupvar\fR commands. |
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| 43 | .SH EXAMPLES |
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| 44 | Store a random number in the variable \fIr\fR: |
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| 45 | .CS |
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| 46 | \fBset\fR r [expr {rand()}] |
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| 47 | .CE |
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| 48 | .PP |
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| 49 | Store a short message in an array element: |
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| 50 | .CS |
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| 51 | \fBset\fR anAry(msg) "Hello, World!" |
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| 52 | .CE |
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| 53 | .PP |
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| 54 | Store a short message in an array element specified by a variable: |
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| 55 | .CS |
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| 56 | \fBset\fR elemName "msg" |
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| 57 | \fBset\fR anAry($elemName) "Hello, World!" |
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| 58 | .CE |
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| 59 | .PP |
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| 60 | Copy a value into the variable \fIout\fR from a variable whose name is |
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| 61 | stored in the \fIvbl\fR (note that it is often easier to use arrays in |
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| 62 | practice instead of doing double-dereferencing): |
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| 63 | .CS |
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| 64 | \fBset\fR in0 "small random" |
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| 65 | \fBset\fR in1 "large random" |
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| 66 | \fBset\fR vbl in[expr {rand() >= 0.5}] |
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| 67 | \fBset\fR out [\fBset\fR $vbl] |
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| 68 | .CE |
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| 69 | .SH "SEE ALSO" |
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| 70 | expr(n), global(n), namespace(n), proc(n), trace(n), unset(n), upvar(n), variable(n) |
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| 71 | .SH KEYWORDS |
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| 72 | read, write, variable |
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