Your code sample isn't quite right. [read stdin] returns a string (not a list of strings), which is parsed as a list when you try to loop over it. The parsing

Your code sample isn't quite right. [read stdin] returns a string (not a list of strings), which is parsed as a list when you try to loop over it. The parsing breaks the string into a list of words, so the second loop is redundant. The parsing could fail if the input file isn't valid list syntax (unmatching {}'s). [split _] makes it safe. foreach word [split [read stdin]] { if [string match *ing $word] { puts $word }} I love Tcl too! Tcl is a scripting language for C, Python is less-powerful version of Lisp.