shuf - writes a random permutation of the input lines to standard output
shuf command without any option
$ shuf
1
2
3
ctrl+d
3
1
2
$ cat file.txt
msg1
msg2
msg3
msg4
msg5
msg6
To shuffle all the lines in the file
$ shuf file.txt
To add the number of lines to shuffle
$ shuf -n 3 file.txt
To make shuf as a range
$ shuf -i 10-30
To get only one output from the randomized range
$ shuf -i 10-100 -n 1
To shuffle a range and allow displaying three outputs which can be
repetitive.
$ shuf -i 10-100 -n 3 -r
To use shuf as a List
$ shuf -e a b c d
$ shuf -e 1 2 3 4
To randomize a list and decide to only output two output lines
$ shuf -e -n 2 1 2 3 4
$ shuf -e -n 2 a b c d
To write output to a file
$ shuf -i 10-20 -o file.txt
$ cat file.txt
regards,
T.Dhanasekar