freebsd-skq/usr.bin/cut/cut.1
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.\" Copyright (c) 1989, 1990, 1993
.\" The Regents of the University of California. All rights reserved.
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.\" This code is derived from software contributed to Berkeley by
.\" the Institute of Electrical and Electronics Engineers, Inc.
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.\" must display the following acknowledgement:
.\" This product includes software developed by the University of
.\" California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
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.\" @(#)cut.1 8.1 (Berkeley) 6/6/93
.\" $FreeBSD$
.\"
.Dd June 6, 1993
.Dt CUT 1
.Os
.Sh NAME
.Nm cut
.Nd select portions of each line of a file
.Sh SYNOPSIS
.Nm
.Fl b Ar list
.Op Fl n
.Op Ar
.Nm
.Fl c Ar list
.Op Ar
.Nm
.Fl f Ar list
.Op Fl d Ar delim
.Op Fl s
.Op Ar
.Sh DESCRIPTION
The
.Nm
utility selects portions of each line (as specified by
.Ar list )
from each
.Ar file
and writes them to the standard output.
If no
.Ar file
arguments are specified, or a file argument is a single dash
.Pq Sq Fl ,
.Nm
reads from from the standard input.
The items specified by
.Ar list
can be in terms of column position or in terms of fields delimited
by a special character.
Column numbering starts from 1.
.Pp
The
.Ar list
option argument
is a comma or whitespace separated set of increasing numbers and/or
number ranges.
Number ranges consist of a number, a dash
.Pq Sq \- ,
and a second number
and select the fields or columns from the first number to the second,
inclusive.
Numbers or number ranges may be preceded by a dash, which selects all
fields or columns from 1 to the first number.
Numbers or number ranges may be followed by a dash, which selects all
fields or columns from the last number to the end of the line.
Numbers and number ranges may be repeated, overlapping, and in any order.
It is not an error to select fields or columns not present in the
input line.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl b Ar list
The
.Ar list
specifies byte positions.
.It Fl c Ar list
The
.Ar list
specifies character positions.
.It Fl d Ar delim
Use the first character of
.Ar delim
as the field delimiter character instead of the tab character.
.It Fl f Ar list
The
.Ar list
specifies fields, delimited in the input by a single tab character.
Output fields are separated by a single tab character.
.It Fl n
Do not split multi-byte characters.
.It Fl s
Suppress lines with no field delimiter characters.
Unless specified, lines with no delimiters are passed through unmodified.
.El
.Sh ENVIRONMENT
The
.Ev LANG , LC_ALL
and
.Ev LC_CTYPE
environment variables affect the execution of
.Nm
if the
.Fl n
option is specified.
Their effect is described in
.Xr environ 7 .
.Sh EXAMPLES
Extract users' login names and shells from the system
.Xr passwd 5
file as
.Dq name:shell
pairs:
.Pp
.Dl "cut -d : -f 1,7 /etc/passwd"
.Pp
Show the names and login times of the currently logged in users:
.Pp
.Dl "who | cut -c 1-16,26-38"
.Sh DIAGNOSTICS
.Ex -std
.Sh SEE ALSO
.Xr paste 1
.Sh STANDARDS
The
.Nm
utility conforms to
.St -p1003.2-92 .
.Sh HISTORY
A
.Nm
command appeared in
.Tn AT&T
System III
.Ux .
.Sh BUGS
The
.Fl c
option is a synonym for the
.Fl b
option, which causes incorrect behaviour in locales that support
multibyte characters.
.Pp
When operating on fields
.Fl ( f
option is specified),
.Nm
does not recognise multibyte characters, and the
.Ar delim
character is recognised in the middle of multibyte sequences.