#!/usr/local/ActiveTcl-8.5/bin/tclsh8.5
 package require fileutil

 ########
 # Essentials

 proc shuffle {list} {
  set n 1
  set slist {}
  foreach item $list {
   set index [expr {int(rand()*$n)}]
   set slist [linsert $slist $index $item]
   incr n
   }
  return $slist
  }

 proc lvarpop {upVar {index 0}} {
  upvar $upVar list;
  if {![info exists list]} { return "-1" }
  set top [lindex $list $index];
  set list [concat [lrange $list 0 [expr $index - 1]] [lrange $list [expr $index +1] end]]
  return $top;
  }

 ########
 # General

 proc get_dirs {} {
  if {![file exists $::dirs_file]} { puts "Error: $::dirs_file does not exist!" ; exit }
  if {![file readable $::dirs_file]} { puts "Error: $::dirs_file unreadable!" ; exit }
  set DF [open $::dirs_file "r"]
  fconfigure $DF -encoding binary -translation binary -buffering none
  set dirs [read $DF]
  close $DF
  return $dirs
  }

 proc random_from_all {items} {
  # Create list
  set fl [list]
  set dirs [get_dirs]
  foreach d $dirs {
   if {![file exists $d]} { continue } ;# Ignore moved/missing directories.
   set mp3 [fileutil::findByPattern $d *.mp3]
   foreach f $mp3 { lappend fl $f }
   # Extra filetypes.
   foreach ext $::othermedia { 
    set mfiles [lsort [fileutil::findByPattern $d -glob *.${ext}]] 
    foreach f $mfiles { lappend fl $f }
    }
   }
  # puts "Full list:\n$fl\n";
  set fl [shuffle $fl]
  set c 0 ; while {$c < $items} { lappend pl [lvarpop fl 0] ; incr c }
  return $pl
  }

 proc ordered_from_random_dirs {items} {
  # Create list
  set fl [list]
  set dl [list]
  set dq [list]
  set pl [list]
  set dirs [get_dirs]
  foreach d $dirs {
   set found [fileutil::findByPattern $d *]
   foreach f $found {
    if {[file isdirectory $f] && [regexp $d $f] } { lappend dl $f }
    }
   }
  # Shuffle directories
  set dl [shuffle $dl]
  set c 0 ; while {$c < $items} { lappend dq [lvarpop dl 0] ; incr c }
  # Collect files inside directories
  foreach d $dq {
   # Standard MP3
   set mp3 [lsort [fileutil::findByPattern $d -glob *.mp3]]
   foreach f $mp3 { lappend pl $f }
   # Extra filetypes.
   foreach ext $::othermedia { 
    set mfiles [lsort [fileutil::findByPattern $d -glob *.$ext]]
    foreach f $mfiles { lappend pl $f } 
    }
   }
  return $pl
  }

 proc set_directories_file {value} { set ::dirs_file $value }
 proc set_toggle_ext {key} {
  # Toggle on or off.
  if {[lsearch $::othermedia $key] < 0} { 
   lappend ::othermedia $key
   } else { 
   lvarpop ::othermedia [lsearch -exact $::othermedia $key] 
   }
  return ok
  }

 ########
 # Main

 interp alias {} -rdof {} ordered_from_random_dirs ;# Random Dirs, Ordered Files
 interp alias {} -rdrf {} random_from_all          ;# Random Dirs, Random Files
 interp alias {} -cf {} set_directories_file       ;# Sets the root dirs file.
 interp alias {} -togext {} set_toggle_ext         ;# Set using extname; toggles

 set ::dirs_file "~/.mp3s/default.cf"
 set ::othermedia [list]

 foreach {opt value} $argv {
  foreach f [$opt $value] {
   if {[string length $f] > 3} { puts $f ; set didsomething 1 }
   }
  }

 if {![info exists didsomething]} {
  puts "Syntax:\n"
  puts " mp3select.sh opt value opt value \[...\]\n"
  puts "Options:\n"
  puts " -rdof X : Random Dirs, Ordered Files; to play X random audioplays."
  puts " -rdrf X : Random Files; for playing X random tracks."
  puts " -cf /path/file.cf : Sets the path to the file with root directories."
  puts " -togext ext : Toggle the inclusion of *.ext files.\n"
  puts "Example:\n"
  puts " mp3select.sh -rdrf 10 -cf ~/punk.cf -rdof 3\n"
  puts " This selects 10 random songs from the dirs in the default file,"
  puts " changes the dirs file to ~/punk.cf then selects 3 random albums.\n"
  puts "Notes:\n"
  puts " * mp3select.sh will not select a song twice in the same option track"
  puts " selection."
  puts " * The -cf setting applies to the next -rdof/-rdrf file selection/s"
  puts " but not previous ones. Multiple -cf may be used."
  puts " * Default file for listing directories: ~/.mp3s/default.cf\n"
  }