split (Unix)

<h2 id="history">History</h2>
<p>The split <a href="/facts/Command_(computing)/zUrvQbFy">command</a> first appeared in <a href="/facts/Ancient_Unix/PAqr4uUA">Version 3 Unix</a><a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a> and is part of the <a href="/facts/X/Open/btwVKbX2">X/Open</a> Portability Guide since issue 2 of 1987. It was inherited into the first version of POSIX.1 and the <a href="/facts/Single_Unix_Specification/w1ba5bDt">Single Unix Specification</a>.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a> The version of split bundled in <a href="/facts/GNU_coreutils/Q9cop5U5">GNU coreutils</a> was written by Torbjorn Granlund and <a href="/facts/Richard_Stallman/hhoPN0Mw">Richard Stallman</a>.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> The split command has also been ported to the <a href="/facts/IBM_i/lsIRAUvn">IBM i</a> operating system.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a>
</p>
<h2 id="usage">Usage</h2>
<p>The command-<a href="/facts/Syntax/6PxSV98p">syntax</a> is:
</p>
 split [OPTION] [INPUT [PREFIX]]

<p>The default behavior of split is to generate output files of a fixed size, default 1000 lines.  The files are named by appending <i>aa</i>, <i>ab</i>, <i>ac</i>, etc. to <i>output filename</i>.  If <i>output filename</i> is not given, the default filename of <i>x</i> is used, for example, <i>xaa</i>, <i>xab</i>, etc.  When a hyphen (<i>-</i>) is used instead of <i>input filename</i>, data is derived from <a href="/facts/Standard_input/r92M7Wd4">standard input</a>. The files are typically rejoined using a utility such as <a href="/facts/Cat_(Unix)/KQPATH6w">cat</a>.
</p><p>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.
</p>
<h3>Split file into pieces</h3>
<p>Create a file named "myfile.txt" with exactly 3,000 lines of data:
</p>
$ head -3000 < /dev/urandom > myfile.txt

<p>Now, use the split command to break this file into pieces (note: unless otherwise specified, split will break the file into 1,000-line files):
</p>
$ 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

<p>As seen above, the split command has broken the original file (keeping the original intact) into three, equal in number of lines (i.e., 1,000), files: xaa, xab, and xac.
</p>
<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Csplit/B2Em6ogs">csplit</a> – splits by content rather than by size</li>
<li><a href="/facts/File_spanning/P9RWg8QT">File spanning</a></li>
<li><a href="/facts/List_of_Unix_commands/EEuIsUx9">List of Unix commands</a></li></ul>

<h2 id="external-links">External links</h2>

The Wikibook <i>Guide to Unix</i> has a page on the topic of: <i>Commands</i>

<ul><li><a href="https://pubs.opengroup.org/onlinepubs/9799919799/utilities/split.html">split</a> – Shell and Utilities Reference, <a href="/facts/Single_Unix_Specification/w1ba5bDt">The Single UNIX Specification</a>, Version 4 from <a href="/facts/The_Open_Group/uRoDdEae">The Open Group</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>split(1) – FreeBSD General Commands Manual <a href="https://www.freebsd.org/cgi/man.cgi?query=split&sektion=1" target="_blank">https://www.freebsd.org/cgi/man.cgi?query=split&sektion=1</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>split – Shell and Utilities Reference, The Single UNIX Specification, Version 4 from The Open Group <a href="https://pubs.opengroup.org/onlinepubs/9799919799/utilities/split.html" target="_blank">https://pubs.opengroup.org/onlinepubs/9799919799/utilities/split.html</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>"split(1): split file into pieces - Linux man page". linux.die.net. <a href="https://linux.die.net/man/1/split" target="_blank">https://linux.die.net/man/1/split</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>IBM. "IBM System i Version 7.2 Programming Qshell" (PDF). IBM. Retrieved 2020-09-05. <a href="/wiki/IBM" target="_blank">/wiki/IBM</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
</ol>

split (Unix) open-in-new

split (Unix)