shuffle
— print a
random permutation of the command line arguments
shuffle |
[-f filename ...]
[-n number]
[-p number]
[arg] [...] |
The shuffle
program prints a random
permutation (or “shuffle”) of its input lines. This can be
useful in shell scripts for selecting a random order in which to do a set of
tasks, view a set of files, etc.
If the -f
option is given, the data is
taken from that files' contents or if the filename is
- “stdin”.
If the -n
option is given, its argument is
treated as a number, and the program prints a random permutation of the
numbers greater than or equal to 0 and less than the argument.
If the -p
option is given, its argument is
treated as a number, and the program prints that number of randomly selected
lines or arguments in a random order.
$ shuffle a b c d
c
b
d
a
$ shuffle -p 1 a b c d
d
$ shuffle -n 4 -p 2
0
3
The shuffle
program first appeared in
NetBSD 1.4.
Written by Perry E. Metzger (perry@piermont.com).
The random number generator isn't that great, and thus the
permutations often aren't that great.