一个被遗忘的shell命令shuf

随机输出，适合构建测试数据的时候使用。

例如：
head -100000 block_0_0.list | shuf  | awk  '{print "http://192.168.16.100:6001/get?UID=" $1}' > /root/webtest/rand10000.txt


NAME
       shuf - generate random permutations

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

DESCRIPTION
       Write a random permutation of the input lines to standard output.

       Mandatory arguments to long options are mandatory for short options too.

       -e, --echo
              treat each ARG as an input line

       -i, --input-range=LO-HI
              treat each number LO through HI as an input line

       -n, --head-count=COUNT
              output at most COUNT lines

       -o, --output=FILE
              write result to FILE instead of standard output

       --random-source=FILE
              get random bytes from FILE

       -z, --zero-terminated
              end lines with 0 byte, not newline

       --help display this help and exit

       --version
              output version information and exit

       With no FILE, or when FILE is -, read standard input.

AUTHOR
       Written by Paul Eggert.