Version 2 of unsort

AMG: unsort is a simple UNIXy stdin->stdout pipeline tool for randomizing line order. It's simple, works quite nicely, and is surprisingly useful.

Without further ado, I present to you the source:

 #!/bin/sh
 # \
 exec tclsh "$0" "$@"

 proc main {} {
     set lines [list]
     foreach line [lrange [split [read stdin] \n] 0 end-1] {
          lappend lines [list [expr {rand()}] $line]
     }

     foreach line [lsort -real -index 0 $lines] {
         puts [lindex $line 1]
     }
 }

 main

 # vim: set ts=4 sts=4 sw=4 tw=80 et ft=tcl:

Even though the above really is good enough, I'm still interested in seeing performance improvements. Any ideas?

Let's give it a try, shall we?

 [andy@blender|~/devel/misc]$ unsort <<EOF
 > alpha
 > bravo
 > charlie
 > delta
 > EOF
 charlie
 bravo
 delta
 alpha

I usually use unsort for creating a randomized playlist:

 [andy@blender|~]$ mplayer $(find ~/media/music -type f | unsort)

Works great! I'm using it right now, as a matter of fact.