Coreutils: https://www.gnu.org/software/coreutils/manual/html_node/shuf-invocation.html
Generate a random permutation of the input lines:
printf 'a\nb\nc\nd\n' | shuf
Possible output:
d
a
c
b
Generate a random permutation of the range {1..4}:
shuf -i1-4
Special case: generate one random integer in range:
shuf -i1-4 -n1
Depending on the use case:
- Bash built-in
RANDOM /dev/random