File: coreutils.info,  Node: shuf invocation,  Next: uniq invocation,  Prev: sort invocation,  Up: Operating on sorted files

7.2 ‘shuf’: Shuffling text
==========================

‘shuf’ shuffles its input by outputting a random permutation of its
input lines.  Each output permutation is equally likely.  Synopses:

     shuf [OPTION]... [FILE]
     shuf -e [OPTION]... [ARG]...
     shuf -i LO-HI [OPTION]...

   ‘shuf’ has three modes of operation that affect where it obtains its
input lines.  By default, it reads lines from standard input.  The
following options change the operation mode:

‘-e’
‘--echo’
     Treat each command-line operand as an input line.

‘-i LO-HI’
‘--input-range=LO-HI’
     Act as if input came from a file containing the range of unsigned
     decimal integers LO...HI, one per line.

   ‘shuf’’s other options can affect its behavior in all operation
modes:

‘-n COUNT’
‘--head-count=COUNT’
     Output at most COUNT lines.  By default, all input lines are
     output.

‘-o OUTPUT-FILE’
‘--output=OUTPUT-FILE’
     Write output to OUTPUT-FILE instead of standard output.  ‘shuf’
     reads all input before opening OUTPUT-FILE, so you can safely
     shuffle a file in place by using commands like ‘shuf -o F