NAME
split - split files into pieces
SYNOPSIS
split [-l line_count][-a suffix_length][file[name]]
split -b n[k|m][-a suffix_length][file[name]]
DESCRIPTION
The split utility shall read an input file and write one or more output
files. The default size of each output file shall be 1000 lines. The
size of the output files can be modified by specification of the -b or
-l options. Each output file shall be created with a unique suffix. The
suffix shall consist of exactly suffix_length lowercase letters from
the POSIX locale. The letters of the suffix shall be used as if they
were a base-26 digit system, with the first suffix to be created
consisting of all ’a’ characters, the second with a ’b’ replacing the
last ’a’ , and so on, until a name of all ’z’ characters is created. By
default, the names of the output files shall be ’x’ , followed by a
two-character suffix from the character set as described above,
starting with "aa" , "ab" , "ac" , and so on, and continuing until the
suffix "zz" , for a maximum of 676 files.
If the number of files required exceeds the maximum allowed by the
suffix length provided, such that the last allowable file would be
larger than the requested size, the split utility shall fail after
creating the last file with a valid suffix; split shall not delete the
files it created with valid suffixes. If the file limit is not
exceeded, the last file created shall contain the remainder of the
input file, and may be smaller than the requested size.
OPTIONS
The split utility shall conform to the Base Definitions volume of
IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
The following options shall be supported:
-a suffix_length
Use suffix_length letters to form the suffix portion of the
filenames of the split file. If -a is not specified, the default
suffix length shall be two. If the sum of the name operand and
the suffix_length option-argument would create a filename
exceeding {NAME_MAX} bytes, an error shall result; split shall
exit with a diagnostic message and no files shall be created.
-b n Split a file into pieces n bytes in size.
-b nk Split a file into pieces n*1024 bytes in size.
-b nm Split a file into pieces n*1048576 bytes in size.
-l line_count
Specify the number of lines in each resulting file piece. The
line_count argument is an unsigned decimal integer. The default
is 1000. If the input does not end with a <newline>, the partial
line shall be included in the last output file.
OPERANDS
The following operands shall be supported:
file The pathname of the ordinary file to be split. If no input file
is given or file is ’-’ , the standard input shall be used.
name The prefix to be used for each of the files resulting from the
split operation. If no name argument is given, ’x’ shall be used
as the prefix of the output files. The combined length of the
basename of prefix and suffix_length cannot exceed {NAME_MAX}
bytes. See the OPTIONS section.
STDIN
See the INPUT FILES section.
INPUT FILES
Any file can be used as input.
ENVIRONMENT VARIABLES
The following environment variables shall affect the execution of
split:
LANG Provide a default value for the internationalization variables
that are unset or null. (See the Base Definitions volume of
IEEE Std 1003.1-2001, Section 8.2, Internationalization
Variables for the precedence of internationalization variables
used to determine the values of locale categories.)
LC_ALL If set to a non-empty string value, override the values of all
the other internationalization variables.
LC_CTYPE
Determine the locale for the interpretation of sequences of
bytes of text data as characters (for example, single-byte as
opposed to multi-byte characters in arguments and input files).
LC_MESSAGES
Determine the locale that should be used to affect the format
and contents of diagnostic messages written to standard error.
NLSPATH
Determine the location of message catalogs for the processing of
LC_MESSAGES .
ASYNCHRONOUS EVENTS
Default.
STDOUT
Not used.
STDERR
The standard error shall be used only for diagnostic messages.
OUTPUT FILES
The output files contain portions of the original input file;
otherwise, unchanged.
EXTENDED DESCRIPTION
None.
EXIT STATUS
The following exit values shall be returned:
0 Successful completion.
>0 An error occurred.
CONSEQUENCES OF ERRORS
Default.
The following sections are informative.
APPLICATION USAGE
None.
EXAMPLES
In the following examples foo is a text file that contains 5000 lines.
1. Create five files, xaa, xab, xac, xad, and xae:
split foo
2. Create five files, but the suffixed portion of the created files
consists of three letters, xaaa, xaab, xaac, xaad, and xaae:
split -a 3 foo
3. Create three files with four-letter suffixes and a supplied prefix,
bar_aaaa, bar_aaab, and bar_aaac:
split -a 4 -l 2000 foo bar_
4. Create as many files as are necessary to contain at most 20*1024
bytes, each with the default prefix of x and a five-letter suffix:
split -a 5 -b 20k foo
RATIONALE
The -b option was added to provide a mechanism for splitting files
other than by lines. While most uses of the -b option are for
transmitting files over networks, some believed it would have
additional uses.
The -a option was added to overcome the limitation of being able to
create only 676 files.
Consideration was given to deleting this utility, using the rationale
that the functionality provided by this utility is available via the
csplit utility (see csplit ). Upon reconsideration of the purpose of
the User Portability Extension, it was decided to retain both this
utility and the csplit utility because users use both utilities and
have historical expectations of their behavior. Furthermore, the
splitting on byte boundaries in split cannot be duplicated with the
historical csplit.
The text " split shall not delete the files it created with valid
suffixes" would normally be assumed, but since the related utility,
csplit, does delete files under some circumstances, the historical
behavior of split is made explicit to avoid misinterpretation.
FUTURE DIRECTIONS
None.
SEE ALSO
csplit
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .