usr.bin/split/split.1

.\" Copyright (c) 1990, 1991, 1993, 1994
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd May 26, 2023
.Dt SPLIT 1
.Os
.Sh NAME
.Nm split
.Nd split a file into pieces
.Sh SYNOPSIS
.Nm
.Op Fl cd
.Op Fl l Ar line_count
.Op Fl a Ar suffix_length
.Op Ar file Op Ar prefix
.Nm
.Op Fl cd
.Fl b Ar byte_count Ns
.Oo
.Sm off
.Cm K | k | M | m | G | g
.Sm on
.Oc
.Op Fl a Ar suffix_length
.Op Ar file Op Ar prefix
.Nm
.Op Fl cd
.Fl n Ar chunk_count
.Op Fl a Ar suffix_length
.Op Ar file Op Ar prefix
.Nm
.Op Fl cd
.Fl p Ar pattern
.Op Fl a Ar suffix_length
.Op Ar file Op Ar prefix
.Sh DESCRIPTION
The
.Nm
utility reads the given
.Ar file
and breaks it up into files of 1000 lines each
(if no options are specified), leaving the
.Ar file
unchanged.
If
.Ar file
is a single dash
.Pq Sq Fl
or absent,
.Nm
reads from the standard input.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl a Ar suffix_length
Use
.Ar suffix_length
letters to form the suffix of the file name.
.It Fl b Ar byte_count Ns Oo
.Sm off
.Cm K | k | M | m | G | g
.Sm on
.Oc
Create split files
.Ar byte_count
bytes in length.
If
.Cm k
or
.Cm K
is appended to the number, the file is split into
.Ar byte_count
kilobyte pieces.
If
.Cm m
or
.Cm M
is appended to the number, the file is split into
.Ar byte_count
megabyte pieces.
If
.Cm g
or
.Cm G
is appended to the number, the file is split into
.Ar byte_count
gigabyte pieces.
.It Fl c
Continue creating files and do not overwrite existing
output files.
.It Fl d
Use a numeric suffix instead of a alphabetic suffix.
.It Fl l Ar line_count
Create split files
.Ar line_count
lines in length.
.It Fl n Ar chunk_count
Split file into
.Ar chunk_count
smaller files.
The first n - 1 files will be of size (size of
.Ar file
/
.Ar chunk_count
)
and the last file will contain the remaining bytes.
.It Fl p Ar pattern
The file is split whenever an input line matches
.Ar pattern ,
which is interpreted as an extended regular expression.
The matching line will be the first line of the next output file.
This option is incompatible with the
.Fl b
and
.Fl l
options.
.El
.Pp
If additional arguments are specified, the first is used as the name
of the input file which is to be split.
If a second additional argument is specified, it is used as a prefix
for the names of the files into which the file is split.
In this case, each file into which the file is split is named by the
prefix followed by a lexically ordered suffix using
.Ar suffix_length
characters in the range
.Dq Li a Ns - Ns Li z .
If
.Fl a
is not specified, two letters are used as the initial suffix.
If the output does not fit into the resulting number of files and the
.Fl d
flag is not specified, then the suffix length is automatically extended as
needed such that all output files continue to sort in lexical order.
.Pp
If the
.Ar prefix
argument is not specified, the file is split into lexically ordered
files named with the prefix
.Dq Li x
and with suffixes as above.
.Pp
By default,
.Nm
will overwrite any existing output files.
If the
.Fl c
flag is specified,
.Nm
will instead create files with names that do not already exist.
.Sh ENVIRONMENT
The
.Ev LANG , LC_ALL , LC_CTYPE
and
.Ev LC_COLLATE
environment variables affect the execution of
.Nm
as described in
.Xr environ 7 .
.Sh EXIT STATUS
.Ex -std
.Sh EXAMPLES
Split input into as many files as needed, so that each file contains at most 2
lines:
.Bd -literal -offset indent
$ echo -e "first line\\nsecond line\\nthird line\\nforth line" | split -l2
.Ed
.Pp
Split input in chunks of 10 bytes using numeric prefixes for file names.
This generates two files of 10 bytes (x00 and x01) and a third file (x02) with the
remaining 2 bytes:
.Bd -literal -offset indent
$ echo -e "This is 22 bytes long" | split -d -b10
.Ed
.Pp
Split input generating 6 files:
.Bd -literal -offset indent
$ echo -e "This is 22 bytes long" | split -n 6
.Ed
.Pp
Split input creating a new file every time a line matches the regular expression
for a
.Dq t
followed by either
.Dq a
or
.Dq u
thus creating two files:
.Bd -literal -offset indent
$ echo -e "stack\\nstock\\nstuck\\nanother line" | split -p 't[au]'
.Ed
.Sh SEE ALSO
.Xr csplit 1 ,
.Xr re_format 7
.Sh STANDARDS
The
.Nm
utility conforms to
.St -p1003.1-2001 .
.Sh HISTORY
A
.Nm
command appeared in
.At v3 .
.Pp
Before
.Fx 14 ,
pattern and line matching only operated on lines shorter than 65,536 bytes.