在linux系统中如何拆分，分割文件，和如何合并文件，通过具体的linux命令来完成，它们分别是split命令与cat命令。
关于文件分割最有用的命令就是split命令了，下面看下split的用法：
NAME
split - split a file into pieces
SYNOPSIS
split [OPTION]... [INPUT [PREFIX]]
DESCRIPTION
Output fixed-size pieces of INPUT to PREFIXaa, PREFIXab, ...; default size is 1000 lines, and default PREFIX is ‘x’. With no INPUT, or when INPUT is
-, read standard input.
Mandatory arguments to long options are mandatory for short options too.
-a, --suffix-length=N
use suffixes of length N (default 2)
-b, --bytes=SIZE
put SIZE bytes per output file
-C, --line-bytes=SIZE
put at most SIZE bytes of lines per output file
-d, --numeric-suffixes
use numeric suffixes instead of alphabetic
-l, --lines=NUMBER
put NUMBER lines per output file
--verbose
print a diagnostic just before each output file is opened
--help display this help and exit
--version
output version information and exit
SIZE may be (or may be an integer optionally followed by) one of following: KB 1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G, T, P, E, Z, Y.
AUTHOR
Written by Torbjorn Granlund and Richard M. Stallman.
REPORTING BUGS
Report split bugs to bug-coreutils@gnu.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
Report split translation bugs to <http://translationproject.org/team/>
COPYRIGHT
Copyright ? 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
The full documentation for split is maintained as a Texinfo manual. If the info and split programs are properly installed at your site, the command
:
1）按行数切分：split -l 2000 要分割的文件 子文件的前缀
2）按大小切分: split -b 20m 要分割的文件 子文件的前缀
3）split -l 2482 ../BLM/BLM.txt -d -a 4 BLM_
将 文件 BLM.txt 分成若干个小文件，每个文件2482行(-l 2482)，文件前缀为BLM_ ，系数不是字母而是数字（-d），后缀系数为四位数（-a 4）
再来看下如何合并多个文件，如果是比较重要的大文件或数据文件，在分割的时候，可以作md5校验和，在合并时重新校验数据，如果发现不一致，则是传输损坏等情况造成，可重新传输：
使用cat命令进行合并：