Split (Unix)


split is a utility on Unix and Unix-like operating systems most commonly used to split a computer file into two or more smaller files.

History

is part of the X/Open Portability Guide since issue 2 of 1987. It was inherited into the first version of POSIX.1 and the Single Unix Specification. It first appeared in Version 3 Unix.
The version of split bundled in GNU coreutils was written by Torbjorn Granlund and Richard Stallman.

Usage

The command-syntax is:

split INPUT [PREFIX

The [default behavior of split is to generate output files of a fixed size, default 1000 lines. The files are named by appending aa, ab, ac, etc. to output filename. If output filename is not given, the default filename of x is used, for example, xaa, xab, etc. When a hyphen is used instead of input filename, data is derived from standard input. The files are typically rejoined using a utilitity such as cat.
Additional program options permit a maximum character count, a maximum line length, how many incrementing characters in generated filenames, and whether to use letters or digits.

Split file into pieces

Create a file named "myfile.txt" with exactly 3,000 lines of data:

$ head -3000 < /dev/urandom > myfile.txt

Now, use the split command to break this file into pieces :

$ split myfile.txt
$ ls -l
-rw-r--r-- 1 root root 761K Jun 16 18:17 myfile.txt
-rw-r--r-- 1 root root 242K Jun 16 18:17 xaa
-rw-r--r-- 1 root root 263K Jun 16 18:17 xab
-rw-r--r-- 1 root root 256K Jun 16 18:17 xac
$ wc --lines xa*
1000 xaa
1000 xab
1000 xac
3000 total

As seen above, the split command has broken the original file into three, equal in number of lines, files: xaa, xab, and xac.

Manual