Provided by: manpages-posix_2013a-1_all bug

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

       cut — cut out selected fields of each line of a file

SYNOPSIS

       cut −b list [−n] [file...]

       cut −c list [file...]

       cut −f list [−d delim] [−s] [file...]

DESCRIPTION

       The cut utility  shall  cut  out  bytes  (−b  option),  characters  (−c
       option),  or  character-delimited  fields (−f option) from each line in
       one or more files, concatenate them, and write them to standard output.

OPTIONS

       The cut utility  shall  conform  to  the  Base  Definitions  volume  of
       POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines.

       The application shall ensure that the option-argument list (see options
       −b, −c, and −f below) is a <comma>-separated list or  <blank>-separated
       list  of positive numbers and ranges. Ranges can be in three forms. The
       first is two positive numbers separated by a <hyphen> (lowhigh), which
       represents  all  fields from the first number to the second number. The
       second is a positive number  preceded  by  a  <hyphen>  (−high),  which
       represents  all fields from field number 1 to that number. The third is
       a positive number followed by a <hyphen> (low−), which represents  that
       number  to  the  last  field,  inclusive.  The  elements in list can be
       repeated, can overlap, and can be  specified  in  any  order,  but  the
       bytes,  characters, or fields selected shall be written in the order of
       the input data. If an element appears in the selection list  more  than
       once, it shall be written exactly once.

       The following options shall be supported:

       −b list   Cut  based  on  a  list of bytes. Each selected byte shall be
                 output unless the −n option is also specified. It  shall  not
                 be an error to select bytes not present in the input line.

       −c list   Cut  based  on  a list of characters. Each selected character
                 shall  be  output.  It  shall  not  be  an  error  to  select
                 characters not present in the input line.

       −d delim  Set  the field delimiter to the character delim.  The default
                 is the <tab>.

       −f list   Cut based on a list of fields, assumed to be separated in the
                 file  by a delimiter character (see −d).  Each selected field
                 shall be output. Output fields shall be separated by a single
                 occurrence  of  the  field delimiter character. Lines with no
                 field delimiters shall be passed through intact, unless −s is
                 specified.  It  shall  not  be  an error to select fields not
                 present in the input line.

       −n        Do not split characters. When specified with the  −b  option,
                 each element in list of the form lowhigh (<hyphen>-separated
                 numbers) shall be modified as follows:

                  *  If the byte selected by low is not the first  byte  of  a
                     character,  low  shall be decremented to select the first
                     byte of the character originally selected by low.  If the
                     byte  selected  by  high  is  not  the  last  byte  of  a
                     character, high shall be decremented to select  the  last
                     byte  of  the character prior to the character originally
                     selected by high, or zero if there is no prior character.
                     If  the resulting range element has high equal to zero or
                     low greater than high, the list element shall be  dropped
                     from list for that input line without causing an error.

                 Each  element  in  list  of the form low− shall be treated as
                 above with high set to the number of  bytes  in  the  current
                 line,  not including the terminating <newline>.  Each element
                 in list of the form −high shall be treated as above with  low
                 set  to  1.  Each  element  in list of the form num (a single
                 number) shall be treated as above with low  set  to  num  and
                 high set to num.

       −s        Suppress  lines  with no delimiter characters, when used with
                 the −f option. Unless specified,  lines  with  no  delimiters
                 shall be passed through untouched.

OPERANDS

       The following operand shall be supported:

       file      A  pathname  of  an  input  file.  If  no  file  operands are
                 specified, or if a file operand is '',  the  standard  input
                 shall be used.

STDIN

       The  standard  input  shall  be  used  only  if  no  file  operands are
       specified, or if a file operand is ''.  See the INPUT FILES section.

INPUT FILES

       The input files shall be text files, except that line lengths shall  be
       unlimited.

ENVIRONMENT VARIABLES

       The following environment variables shall affect the execution of cut:

       LANG      Provide   a   default   value  for  the  internationalization
                 variables that are unset or null. (See the  Base  Definitions
                 volume  of  POSIX.1‐2008,  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

       The cut utility output shall be a concatenation of the selected  bytes,
       characters, or fields (one of the following):

           "%s\n", <concatenation of bytes>

           "%s\n", <concatenation of characters>

           "%s\n", <concatenation of fields and field delimiters>

STDERR

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES

       None.

EXTENDED DESCRIPTION

       None.

EXIT STATUS

       The following exit values shall be returned:

        0    All input files were output successfully.

       >0    An error occurred.

CONSEQUENCES OF ERRORS

       Default.

       The following sections are informative.

APPLICATION USAGE

       The  cut  and  fold  utilities  can be used to create text files out of
       files with arbitrary line lengths. The cut utility should be used  when
       the  number  of  lines  (or records) needs to remain constant. The fold
       utility should be used when the contents of long lines need to be  kept
       contiguous.

       Earlier  versions  of  the  cut  utility worked in an environment where
       bytes and characters were considered equivalent (modulo <backspace> and
       <tab>  processing  in  some  implementations). In the extended world of
       multi-byte characters, the new −b option has been added. The −n  option
       (used  with  −b)  allows  it  to  be  used  to  act on bytes rounded to
       character boundaries.  The algorithm specified for −n guarantees that:

           cutb 1500n file > file1
           cutb 501− −n file > file2

       ends up with all the characters in file appearing exactly once in file1
       or  file2.  (There is, however, a <newline> in both file1 and file2 for
       each <newline> in file.)

EXAMPLES

       Examples of the option qualifier list:

       1,4,7   Select the first, fourth, and  seventh  bytes,  characters,  or
               fields and field delimiters.

       1−3,8   Equivalent to 1,2,3,8.

       −5,10   Equivalent to 1,2,3,4,5,10.

       3−      Equivalent to third to last, inclusive.

       The  lowhigh  forms are not always equivalent when used with −b and −n
       and multi-byte characters; see the description of −n.

       The following command:

           cutd :f 1,6 /etc/passwd

       reads the System V password file (user database) and produces lines  of
       the form:

           <user ID>:<home directory>

       Most  utilities  in this volume of POSIX.1‐2008 work on text files. The
       cut utility can be used to turn files with arbitrary line lengths  into
       a  set of text files containing the same data. The paste utility can be
       used to create (or recreate) files with  arbitrary  line  lengths.  For
       example, if file contains long lines:

           cutb 1500n file > file1
           cutb 501− −n file > file2

       creates  file1  (a text file) with lines no longer than 500 bytes (plus
       the <newline>) and file2 that contains the remainder of the  data  from
       file.   (Note  that file2 is not a text file if there are lines in file
       that are longer than 500 + {LINE_MAX} bytes.) The original file can  be
       recreated from file1 and file2 using the command:

           pasted "\0" file1 file2 > file

RATIONALE

       Some  historical implementations do not count <backspace> characters in
       determining character counts with the −c option. This may be useful for
       using  cut for processing nroff output. It was deliberately decided not
       to have the −c option treat either <backspace> or <tab>  characters  in
       any  special  fashion.  The  fold  utility  does treat these characters
       specially.

       Unlike other utilities, some historical  implementations  of  cut  exit
       after  not finding an input file, rather than continuing to process the
       remaining file operands. This behavior is prohibited by this volume  of
       POSIX.1‐2008, where only the exit status is affected by this problem.

       The  behavior  of  cut  when  provided  with  either mutually-exclusive
       options or options  that  do  not  work  logically  together  has  been
       deliberately  left  unspecified  in  favor of global wording in Section
       1.4, Utility Description Defaults.

       The OPTIONS section was changed in response to IEEE PASC Interpretation
       1003.2  #149.  The  change  represents historical practice on all known
       systems. The original standard was  ambiguous  on  the  nature  of  the
       output.

       The  list option-arguments are historically used to select the portions
       of the line to be written, but do not affect the order of the data. For
       example:

           echo abcdefghi | cutc6,2,47,1

       yields "abdefg".

       A proposal to enhance cut with the following option:

       −o    Preserve the selected field order. When this option is specified,
             each byte, character, or field  (or  ranges  of  such)  shall  be
             written  in the order specified by the list option-argument, even
             if this requires multiple outputs of the same bytes,  characters,
             or fields.

       was  rejected  because this type of enhancement is outside the scope of
       the IEEE P1003.2b draft standard.

FUTURE DIRECTIONS

       None.

SEE ALSO

       Section 2.5, Parameters and Variables, fold, grep, paste

       The Base Definitions volume of  POSIX.1‐2008,  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, 2013 Edition, Standard for Information Technology
       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
       Specifications  Issue  7,  Copyright  (C)  2013  by  the  Institute  of
       Electrical and Electronics Engineers, Inc and The Open Group.  (This is
       POSIX.1-2008 with the 2013 Technical Corrigendum  1  applied.)  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.unix.org/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 .