incr(n) [osx man page]

incr(n) 						       Tcl Built-In Commands							   incr(n)

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NAME

       incr - Increment the value of a variable

SYNOPSIS

       incr varName ?increment?
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DESCRIPTION

       Increments the value stored in the variable whose name is varName.  The value of the variable must be an integer.  If increment is supplied
       then its value (which must be an integer) is added to the value of variable varName;  otherwise 1 is added to varName.  The  new  value	is
       stored as a decimal string in variable varName and also returned as result.

       Starting  with  the Tcl 8.5 release, the variable varName passed to incr may be unset, and in that case, it will be set to the value incre- |
       ment or to the default increment value of 1.

EXAMPLES

       Add one to the contents of the variable x:
	      incr x

       Add 42 to the contents of the variable x:
	      incr x 42

       Add the contents of the variable y to the contents of the variable x:
	      incr x $y

       Add nothing at all to the variable x (often useful for checking whether an argument to a procedure is actually integral and  generating	an
       error if it is not):
	      incr x 0

SEE ALSO

       expr(n)

KEYWORDS

       add, increment, variable, value

Tcl																	   incr(n)

set(n)							       Tcl Built-In Commands							    set(n)

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NAME

       set - Read and write variables

SYNOPSIS

       set varName ?value?
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DESCRIPTION

       Returns	the  value  of	variable  varName.   If value is specified, then set the value of varName to value, creating a new variable if one
       doesn't already exist, and return its value.  If varName contains an open parenthesis and ends with a close parenthesis, then it refers	to
       an  array  element:  the characters before the first open parenthesis are the name of the array, and the characters between the parentheses
       are the index within the array.	Otherwise varName refers to a scalar variable.	Normally, varName is unqualified  (does  not  include  the
       names of any containing namespaces), and the variable of that name in the current namespace is read or written.	If varName includes names-
       pace qualifiers (in the array name if it refers to an array element), the variable in the specified namespace is read or written.

       If no procedure is active, then varName refers to a namespace variable (global variable if the current namespace is the global  namespace).
       If  a  procedure  is active, then varName refers to a parameter or local variable of the procedure unless the global command was invoked to
       declare varName to be global, or unless a variable command was invoked to declare varName to be a namespace variable.

SEE ALSO

       expr(n), proc(n), trace(n), unset(n)

KEYWORDS

       read, write, variable

Tcl																	    set(n)