| [25] | 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: incr.n,v 1.6 2006/02/09 17:34:41 dgp Exp $ | 
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 | 9 | '\"  | 
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 | 10 | .so man.macros | 
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 | 11 | .TH incr 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 | incr \- Increment the value of a variable | 
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 | 16 | .SH SYNOPSIS | 
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 | 17 | \fBincr \fIvarName \fR?\fIincrement\fR? | 
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 | 18 | .BE | 
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 | 19 |  | 
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 | 20 | .SH DESCRIPTION | 
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 | 21 | .PP | 
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 | 22 | Increments the value stored in the variable whose name is \fIvarName\fR. | 
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 | 23 | The value of the variable must be an integer. | 
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 | 24 | If \fIincrement\fR is supplied then its value (which must be an | 
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 | 25 | integer) is added to the value of variable \fIvarName\fR;  otherwise | 
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 | 26 | 1 is added to \fIvarName\fR. | 
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 | 27 | The new value is stored as a decimal string in variable \fIvarName\fR | 
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 | 28 | and also returned as result. | 
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 | 29 | .PP | 
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 | 30 | .VS 8.5 | 
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 | 31 | Starting with the Tcl 8.5 release, the variable \fIvarName\fR passed | 
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 | 32 | to \fBincr\fR may be unset, and in that case, it will be set to | 
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 | 33 | the value \fIincrement\fR or to the default increment value of \fB1\fR. | 
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 | 34 | .VE 8.5 | 
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 | 35 | .SH EXAMPLES | 
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 | 36 | Add one to the contents of the variable \fIx\fR: | 
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 | 37 | .CS | 
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 | 38 | \fBincr\fR x | 
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 | 39 | .CE | 
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 | 40 | .PP | 
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 | 41 | Add 42 to the contents of the variable \fIx\fR: | 
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 | 42 | .CS | 
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 | 43 | \fBincr\fR x 42 | 
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 | 44 | .CE | 
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 | 45 | .PP | 
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 | 46 | Add the contents of the variable \fIy\fR to the contents of the | 
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 | 47 | variable \fIx\fR: | 
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 | 48 | .CS | 
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 | 49 | \fBincr\fR x $y | 
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 | 50 | .CE | 
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 | 51 | .PP | 
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 | 52 | Add nothing at all to the variable \fIx\fR (often useful for checking | 
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 | 53 | whether an argument to a procedure is actually integral and generating | 
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 | 54 | an error if it is not): | 
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 | 55 | .CS | 
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 | 56 | \fBincr\fR x 0 | 
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 | 57 | .CE | 
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 | 58 |  | 
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 | 59 | .SH "SEE ALSO" | 
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 | 60 | expr(n) | 
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 | 61 |  | 
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 | 62 | .SH KEYWORDS | 
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 | 63 | add, increment, variable, value | 
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