man-pages/man1p/split.1p

.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved 
.TH "SPLIT" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\" split 
.SH NAME
split \- split files into pieces
.SH SYNOPSIS
.LP
\fBsplit\fP \fB[\fP\fB-l\fP \fIline_count\fP\fB][\fP\fB-a\fP
\fIsuffix_length\fP\fB][\fP\fIfile\fP\fB[\fP\fIname\fP\fB]]\fP\fB
.br
.sp
split -b\fP \fIn\fP\fB[\fP\fBk|m\fP\fB][\fP\fB-a\fP
\fIsuffix_length\fP\fB][\fP\fIfile\fP\fB[\fP\fIname\fP\fB]]\fP\fB\fP
\fB
.br
\fP
.SH DESCRIPTION
.LP
The \fIsplit\fP 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 \fB-b\fP or \fB-l\fP options. Each output
file shall be created with a unique suffix. The suffix shall consist
of exactly \fIsuffix_length\fP 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 \fB'a'\fP characters, the second with a \fB'b'\fP
replacing the last \fB'a'\fP , and so on, until a name
of all \fB'z'\fP characters is created. By default, the names of the
output files shall be \fB'x'\fP , followed by a
two-character suffix from the character set as described above, starting
with \fB"aa"\fP , \fB"ab"\fP , \fB"ac"\fP , and
so on, and continuing until the suffix \fB"zz"\fP , for a maximum
of 676 files.
.LP
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 \fIsplit\fP utility shall
fail after creating the last file with a valid suffix;
\fIsplit\fP 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.
.SH OPTIONS
.LP
The \fIsplit\fP utility shall conform to the Base Definitions volume
of IEEE\ Std\ 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
.LP
The following options shall be supported:
.TP 7
\fB-a\ \fP \fIsuffix_length\fP
.sp
Use \fIsuffix_length\fP letters to form the suffix portion of the
filenames of the split file. If \fB-a\fP is not specified, the
default suffix length shall be two. If the sum of the \fIname\fP operand
and the \fIsuffix_length\fP option-argument would create
a filename exceeding {NAME_MAX} bytes, an error shall result; \fIsplit\fP
shall exit with a diagnostic message and no files shall
be created.
.TP 7
\fB-b\ \fP \fIn\fP
Split a file into pieces \fIn\fP bytes in size.
.TP 7
\fB-b\ \fP \fIn\fP\fBk\fP
Split a file into pieces \fIn\fP*1024 bytes in size.
.TP 7
\fB-b\ \fP \fIn\fP\fBm\fP
Split a file into pieces \fIn\fP*1048576 bytes in size.
.TP 7
\fB-l\ \fP \fIline_count\fP
Specify the number of lines in each resulting file piece. The \fIline_count\fP
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.
.sp
.SH OPERANDS
.LP
The following operands shall be supported:
.TP 7
\fIfile\fP
The pathname of the ordinary file to be split. If no input file is
given or \fIfile\fP is \fB'-'\fP , the standard input
shall be used.
.TP 7
\fIname\fP
The prefix to be used for each of the files resulting from the split
operation. If no \fIname\fP argument is given,
\fB'x'\fP shall be used as the prefix of the output files. The combined
length of the basename of \fIprefix\fP and
\fIsuffix_length\fP cannot exceed {NAME_MAX} bytes. See the OPTIONS
section.
.sp
.SH STDIN
.LP
See the INPUT FILES section.
.SH INPUT FILES
.LP
Any file can be used as input.
.SH ENVIRONMENT VARIABLES
.LP
The following environment variables shall affect the execution of
\fIsplit\fP:
.TP 7
\fILANG\fP
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.)
.TP 7
\fILC_ALL\fP
If set to a non-empty string value, override the values of all the
other internationalization variables.
.TP 7
\fILC_CTYPE\fP
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).
.TP 7
\fILC_MESSAGES\fP
Determine the locale that should be used to affect the format and
contents of diagnostic messages written to standard
error.
.TP 7
\fINLSPATH\fP
Determine the location of message catalogs for the processing of \fILC_MESSAGES
\&.\fP 
.sp
.SH ASYNCHRONOUS EVENTS
.LP
Default.
.SH STDOUT
.LP
Not used.
.SH STDERR
.LP
The standard error shall be used only for diagnostic messages.
.SH OUTPUT FILES
.LP
The output files contain portions of the original input file; otherwise,
unchanged.
.SH EXTENDED DESCRIPTION
.LP
None.
.SH EXIT STATUS
.LP
The following exit values shall be returned:
.TP 7
\ 0
Successful completion.
.TP 7
>0
An error occurred.
.sp
.SH CONSEQUENCES OF ERRORS
.LP
Default.
.LP
\fIThe following sections are informative.\fP
.SH APPLICATION USAGE
.LP
None.
.SH EXAMPLES
.LP
In the following examples \fBfoo\fP is a text file that contains 5000
lines.
.IP " 1." 4
Create five files, \fBxaa\fP, \fBxab\fP, \fBxac\fP, \fBxad\fP, and
\fBxae\fP:
.sp
.RS
.nf

\fBsplit foo
\fP
.fi
.RE
.LP
.IP " 2." 4
Create five files, but the suffixed portion of the created files consists
of three letters, \fBxaaa\fP, \fBxaab\fP,
\fBxaac\fP, \fBxaad\fP, and \fBxaae\fP:
.sp
.RS
.nf

\fBsplit -a 3 foo
\fP
.fi
.RE
.LP
.IP " 3." 4
Create three files with four-letter suffixes and a supplied prefix,
\fBbar_aaaa\fP, \fBbar_aaab\fP, and \fBbar_aaac\fP:
.sp
.RS
.nf

\fBsplit -a 4 -l 2000 foo bar_
\fP
.fi
.RE
.LP
.IP " 4." 4
Create as many files as are necessary to contain at most 20*1024 bytes,
each with the default prefix of \fBx\fP and a
five-letter suffix:
.sp
.RS
.nf

\fBsplit -a 5 -b 20k foo
\fP
.fi
.RE
.LP
.SH RATIONALE
.LP
The \fB-b\fP option was added to provide a mechanism for splitting
files other than by lines. While most uses of the \fB-b\fP
option are for transmitting files over networks, some believed it
would have additional uses.
.LP
The \fB-a\fP option was added to overcome the limitation of being
able to create only 676 files.
.LP
Consideration was given to deleting this utility, using the rationale
that the functionality provided by this utility is
available via the \fIcsplit\fP utility (see \fIcsplit\fP ). Upon
reconsideration of the purpose of the User Portability Extension,
it was decided to retain both this utility and the \fIcsplit\fP utility
because users use both utilities and have historical expectations
of their
behavior. Furthermore, the splitting on byte boundaries in \fIsplit\fP
cannot be duplicated with the historical \fIcsplit\fP.
.LP
The text " \fIsplit\fP shall not delete the files it created with
valid suffixes" would normally be assumed, but since the
related utility, \fIcsplit\fP, does delete files under some circumstances,
the historical
behavior of \fIsplit\fP is made explicit to avoid misinterpretation.
.SH FUTURE DIRECTIONS
.LP
None.
.SH SEE ALSO
.LP
\fIcsplit\fP
.SH 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 .