# split

## PROLOG



           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



           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** _n_**k** Split a file into pieces _n_ *1024 bytes in size.
    
           **-b** _n_**m** 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 **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(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
           _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.
    


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