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Diffstat (limited to 'doc/incr.n')
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diff --git a/doc/incr.n b/doc/incr.n new file mode 100644 index 0000000..9052c5a --- /dev/null +++ b/doc/incr.n @@ -0,0 +1,61 @@ +'\" +'\" 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. +'\" +.TH incr n "" Tcl "Tcl Built-In Commands" +.so man.macros +.BS +'\" Note: do not modify the .SH NAME line immediately below! +.SH NAME +incr \- Increment the value of a variable +.SH SYNOPSIS +\fBincr \fIvarName \fR?\fIincrement\fR? +.BE +.SH DESCRIPTION +.PP +Increments the value stored in the variable whose name is \fIvarName\fR. +The value of the variable must be an integer. +If \fIincrement\fR is supplied then its value (which must be an +integer) is added to the value of variable \fIvarName\fR; otherwise +1 is added to \fIvarName\fR. +The new value is stored as a decimal string in variable \fIvarName\fR +and also returned as result. +.PP +Starting with the Tcl 8.5 release, the variable \fIvarName\fR passed +to \fBincr\fR may be unset, and in that case, it will be set to +the value \fIincrement\fR or to the default increment value of \fB1\fR. +.SH EXAMPLES +.PP +Add one to the contents of the variable \fIx\fR: +.PP +.CS +\fBincr\fR x +.CE +.PP +Add 42 to the contents of the variable \fIx\fR: +.PP +.CS +\fBincr\fR x 42 +.CE +.PP +Add the contents of the variable \fIy\fR to the contents of the +variable \fIx\fR: +.PP +.CS +\fBincr\fR x $y +.CE +.PP +Add nothing at all to the variable \fIx\fR (often useful for checking +whether an argument to a procedure is actually integral and generating +an error if it is not): +.PP +.CS +\fBincr\fR x 0 +.CE +.SH "SEE ALSO" +expr(n), set(n) +.SH KEYWORDS +add, increment, variable, value |