NAME

       rl - Randomize Lines.

SYNOPSIS

       rl [OPTION]...  [FILE]...

DESCRIPTION

       rl  reads lines from a input file or stdin, randomizes the lines and outputs a specified number of lines.
       It does this with only a single pass over the input while trying to use as little memory as possible.

       -c, --count=N
              Select the number of lines to be returned in the output.  If this  argument  is  omitted  all  the
              lines  in  the  file  will  be  returned  in  random order.  If the input contains less lines than
              specified and the --reselect option below is not specified a warning is printed and all lines  are
              returned in random order.

       -r, --reselect
              When  using  this  option  a single line may be selected multiple times.  The default behaviour is
              that any input line will only be selected once.  This  option  makes  it  possible  to  specify  a
              --count option with more lines than the file actually holds.

       -o, --output=FILE
              Send randomized lines to FILE instead of stdout.

       -d, --delimiter=DELIM
              Use specified character as a "line" delimiter instead of the newline character.

       -0, --null
              Input  lines  are  terminated by a null character.  This option is useful to process the output of
              the GNU find -print0 option.

       -n, --line-number
              Output lines are numbered with the line number from the input file.

       -q, --quiet, --silent
              Be quiet about any errors or warnings.

       -h, --help
              Show short summary of options.

       -v, --version
              Show version of program.

EXAMPLES

       Some simple demonstrations of how rl can help you do everyday tasks.

       Play a random sound after 4 minutes (perfect for toast):
           sleep 240 ; play `find /sounds -name ´*.au´ -print | rl --count=1`

       Play the 15 most recent .mp3 files in random order.
           ls -c *.mp3 | head -n 15 | rl  | xargs --delimiter=´\n´ play

       Roll a dice:
           seq 6 | rl --count 2

       Roll a dice 1000 times and see which number comes up more often:
           seq 6 | rl --reselect --count 1000 | sort | uniq -c | sort -n

       Shuffle the words of a sentence:
           echo -n "The rain in Spain stays mainly in the plain." \
             | rl --delimiter=´ ´;echo

       Find all movies and play them in random order.
           find . -name ´*.avi´ -print0 | rl -0 | xargs -n 1 -0 mplayer
       Because -0 is used filenames with spaces (even newlines and other unusual characters) in them work.

BUGS

       The program currently does not have very smart memory management.  If you feed it huge files  and  expect
       it  to  fully  randomize all lines it will completely read the file in memory. If you specify the --count
       option it will only use the memory required for storing the specified number of lines.   Improvements  on
       this area are on the TODO list.

       The  program  uses  the  rand()  system  random  function.   This function returns a number between 0 and
       RAND_MAX, which may not be very large on some systems.  This will result in non-random results for  files
       containing more lines than RAND_MAX.

       Note  that  if you specify multiple input files they are randomized per file.  This is a different result
       from when you cat all the files and pipe the result into rl.

COPYRIGHT

       Copyright © 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Arthur de Jong.
       This is free software; see the license for copying conditions.   There  is  NO  warranty;  not  even  for
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Version 0.2.7                                       Jul 2008                                               rl(1)