SPLIT(1)                   POSIX Programmer's Manual                  SPLIT(1)



PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NAME
       split -- split a file 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 zero 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. If the input is
       an empty file, no output file shall be created and this shall not be
       considered to be an error.

OPTIONS
       The split utility shall conform to the Base Definitions volume of
       POSIX.1-2017, 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 _nkk     Split a file into pieces _n*1024 bytes in size.

       -b _nmm     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 POSIX.1-2017, 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 xx 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 Utilities option, 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.

       Earlier versions of this standard allowed a --line__count option. This
       form is no longer specified by POSIX.1-2008 but may be present in some
       implementations.

FUTURE DIRECTIONS
       None.

SEE ALSO
       csplit

       The Base Definitions volume of POSIX.1-2017, Chapter _8, Environment
       Variables, Section 12.2, Utility Syntax Guidelines

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                             SPLIT(1)
