RL(1) User Commands RL(1)
NAME
rl - Randomize Lines.
SYNOPSIS
rl [OPTION]... [FILE]...
DESCRIPTION
rl reads lines from a input file(1,n) 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(1,8) the output. If
this argument is omited all the lines in(1,8) the file(1,n) will be
returned in(1,8) random(3,4,6) order. If the input contains less(1,3) lines than
specified and the --reselect option below is not specified a
warning is printed and all lines are returned in(1,8) random(3,4,6) 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(1,n) 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.
-q, --quiet, --silent
Be quiet about any errors or warnings.
-h, --help
Show short summary of options.
-v, --version
Show version(1,3,5) of program.
EXAMPLES
Some simple demonstrations of how rl can help you do everyday tasks.
Warning: some of these examples may affect the operation of your
system.
Play a random(3,4,6) sound after 4 minutes (perfect for toast):
sleep(1,3) 240 ; play `find /sounds -name '*.au' -print | rl --count=1`
Renice all the processes of a random(3,4,6) logged-in user:
renice +5 -u `who | cut '-d ' -f 1 | sort(1,3) -u | rl --count=1`
Kill a random(3,4,6) process on your computer.
kill(1,2,1 builtins) -9 `ps -A | awk '{print $1}' | rl --count=1`
Do this as root and see how long your system keeps working. Increase
the --count for extra effect. (you may need to change the ps and awk
parameters depending on your system)
Find all movies and play them in(1,8) random(3,4,6) 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(1,8) them work.
COPYRIGHT
Copyright 2001, 2002, 2003 Arthur de Jong
<arthur@tiefighter.et.tudelft.nl>.
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 0.2.2 Oct 2003 RL(1)