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 does not 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.

       If varName includes namespace qualifiers (in the array name  if  it  refers  to  an  array
       element),  or  if  varName  is  unqualified  (does not include the names of any containing
       namespaces) but no procedure is active, varName refers to a  namespace  variable  resolved
       according to the rules described under NAME RESOLUTION in the namespace manual page.

       If a procedure is active and varName is unqualified, then varName refers to a parameter or
       local variable of the procedure,  unless  varName  was  declared  to  resolve  differently
       through one of the global, variable or upvar commands.

EXAMPLES

       Store a random number in the variable r:

              set r [expr {rand()}]

       Store a short message in an array element:

              set anAry(msg) "Hello, World!"

       Store a short message in an array element specified by a variable:

              set elemName "msg"
              set anAry($elemName) "Hello, World!"

       Copy  a  value into the variable out from a variable whose name is stored in the vbl (note
       that it is often easier to use arrays in practice instead of doing double-dereferencing):

              set in0 "small random"
              set in1 "large random"
              set vbl in[expr {rand() >= 0.5}]
              set out [set $vbl]

SEE ALSO

       expr(3tcl),   global(3tcl),   namespace(3tcl),   proc(3tcl),   trace(3tcl),   unset(3tcl),
       upvar(3tcl), variable(3tcl)

KEYWORDS

       read, write, variable