split(1p) — Linux manual page


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

PROLOG         top

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

NAME         top

       split — split a file into pieces

SYNOPSIS         top

       split [-l line_count] [-a suffix_length] [file [name]]

       split -b n[k|m] [-a suffix_length] [file [name]]

DESCRIPTION         top

       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         top

       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

       -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         top

       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         top

       See the INPUT FILES section.

INPUT FILES         top

       Any file can be used as input.


       The following environment variables shall affect the execution of

       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).

                 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.



STDOUT         top

       Not used.

STDERR         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top

       The output files contain portions of the original input file;
       otherwise, unchanged.



EXIT STATUS         top

       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.



       The following sections are informative.



EXAMPLES         top

       In the following examples foo is a text file that contains 5000

        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

               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         top

       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(1p)).  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

       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

       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.



SEE ALSO         top


       The Base Definitions volume of POSIX.1‐2017, Chapter 8,
       Environment Variables, Section 12.2, Utility Syntax Guidelines

COPYRIGHT         top

       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(1P)

Pages that refer to this page: csplit(1p)