split (Unix)

split is a Unix utility most commonly used to split a file into two or more smaller files.

Usage

The command-syntax is:

 split [OPTION] [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.

To split filename to parts each 50 MB named partaa, partab, partac,....

 split -b50m filename part

To join the files back together again use the cat command

 cat xaa xab xac > filename

or

 cat xa[a-c] > filename

or even

 cat xa? > filename

Additional program options permit a maximum character count (instead of a line count), a maximum line length, how many incrementing characters in generated filenames, and whether to use letters or digits.

Manual

• split – Commands & Utilities Reference, The Single UNIX® Specification, Issue 7 from The Open Group

See also

• csplit – splits by content rather than by size
• File spanning
• List of Unix utilities