string reverse string
Returns a string containing the characters of its input argument, string, in reverse order.
Implemented in the Changes in Tcl/Tk 8.5, as part of TIP #272[L1 ].
Workaround substitute for 8.4:
proc string'reverse str {
set res {}
set i [string length $str]
while {$i > 0} {append res [string index $str [incr i -1]]}
set res
} ;# RS
% string'reverse "hello, world"
dlrow ,olleh[Tcl syntax help|Category Command|Category String Processing]