http://www.purl.org/tcl/home/man/tcl8.4/TclCmd/join.htm
Join converts a Tcl list into a string. It glues together the elements of a list using a supplied character as element seperator. Default is a space.
RS A typical application is to process a text that consists of several lines:
foreach line [split $input \n] {
# do something with line, produce output
lappend outlines $out
}
set result [join $outlines \n] Tcl syntax help - Arts and crafts of Tcl-Tk programming - Category Command