| 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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