GNU Coreutils - The shuf Command

The shuf command takes input from stdin, then passes them to stdout in random order.

The call signature is:

shuf {options} {file}

When file is specified, lines from the specified file are read and passed to stdin.

The basic operation is simple. Given the following content:

ninja$:·cat·colors.csv

red,#f00

green,#0f0

blue,#00f

yellow,#ff0

cyan,#0ff

magenta,#f0f

ninja$:··

The lines can be randomized using:

ninja$:·shuf·colors.csv

magenta,#f0f

yellow,#ff0

blue,#00f

cyan,#0ff

red,#f00

green,#0f0

ninja$:··

Repeating this command generates a new random sequence:

ninja$:·shuf·colors.csv

red,#f00

magenta,#f0f

yellow,#ff0

cyan,#0ff

blue,#00f

green,#0f0

ninja$:··

shuf includes the ability to generate a sequence of random integers within a specified range using the -i option, followed by a range spec. For example, to generate a sequence of random integers between 0 and 5 (inclusive):

ninja$:·shuf·-i·0-5

ninja$:··

shuf can also generate random sequences from a set of arguments, using the -e option. For example, to generate a random sequence of letters one could execute:

ninja$:·shuf·-e·a·b·c·d·e

ninja$:··