diff options
Diffstat (limited to 'doc/incr.n')
| -rw-r--r-- | doc/incr.n | 41 |
1 files changed, 34 insertions, 7 deletions
@@ -5,10 +5,8 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: incr.n,v 1.3 2000/09/07 14:27:48 poenitz Exp $ -'\" -.so man.macros .TH incr n "" Tcl "Tcl Built-In Commands" +.so man.macros .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME @@ -16,7 +14,6 @@ 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. @@ -26,9 +23,39 @@ 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) - +expr(n), set(n) .SH KEYWORDS add, increment, variable, value |