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:
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ninja$:·cat·colors.csv
red,#f00
green,#0f0
blue,#00f
yellow,#ff0
cyan,#0ff
magenta,#f0f
ninja$:··
The lines can be randomized using:
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ninja$:·shuf·colors.csv
magenta,#f0f
red,#f00
cyan,#0ff
green,#0f0
yellow,#ff0
blue,#00f
ninja$:··
Repeating this command generates a new random sequence:
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ninja$:·shuf·colors.csv
magenta,#f0f
yellow,#ff0
green,#0f0
cyan,#0ff
blue,#00f
red,#f00
ninja$:··
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):
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ninja$:·shuf·-i·0-5
2
4
5
1
3
0
ninja$:··
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:
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ninja$:·shuf·-e·a·b·c·d·e
a
c
d
b
e
ninja$:··