4.3BSD-UWisc/man/man1/cut.1

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.TH CUT 1
.SH NAME
cut \- cut out selected fields of each line of a file
.SH SYNOPSIS
\fBcut \-c\fP\^list [\|file1 file2 ...]
.br
\fBcut \-f\fP\^list [\fB\-d\fP\|char\|] [\fB\-s\fP] [\|file1 file2 ...]
.SH DESCRIPTION
Use
.I cut\^
to cut out columns from a table or 
fields from each line of a file; in data base parlance, it implements
the projection of a relation.
The fields as specified by
.I list\^
can be fixed length,
i.e., character positions as on a punched card
(\fB\-c\fP option), or the length can vary from line to line
and be marked with a field delimiter character like
.I tab\^
(\fB\-f\fP option).
.I Cut\^
can be used as a filter;
if no files are given, the standard input is used.
.PP
The meanings of the options are:
.br
.TP "\w'\-d\ char\ \ 'u"
.I list\^
A comma-separated 
list of integer field numbers (in increasing order),
with optional \fB\-\fP to indicate ranges
as in the 
.B \-o
option of
.IR nroff / troff
for page ranges;
e.g.,
.BR 1,4,7 ;
.BR 1\-3,8 ;
.B \-5,10
(short for \fB1\-5,10\fP); or
.B 3\-
(short for third through last field).
.TP
\fB\-c\fP\^\fIlist\fP
The
.I list\^
following 
.B \-c
(no space) specifies character
positions (e.g.,
.B \-c1\-72
would pass the first 72 characters
of each line).
.TP
\fB\-f\fP\^\fIlist\fP
The \fIlist\fP following 
.B \-f
is a list of fields
assumed to be separated in the file by a delimiter character (see 
.B \-d
);
e.g. ,
.B \-f1,7
copies the first and seventh field only.
Lines with no field delimiters will be passed through intact (useful
for table subheadings), unless 
.B \-s
is specified.
.TP
\fB\-d\fP\^\fIchar\fP
The character following 
.B \-d
is the field delimiter
(\c
.B \-f
option only).
Default is
.IR tab .
Space or other characters with special meaning to the shell must be quoted.
.TP
.B \-s
Suppresses lines with no delimiter characters in case of
.B \-f
option.
Unless specified, lines with no delimiters will be passed through untouched.
.PP
Either the
.B \-c
or 
.B \-f
option must be specified.
.SH HINTS
Use
.IR grep (1)
to make horizontal ``cuts''
(by context) through a file, or
.IR paste (1)
to put files together column-wise
(i.e., horizontally).
To reorder columns in a table, use
.I cut\^
and
.IR paste .
.SH EXAMPLES
.TP 2.25i
cut \-d: \-f1,5 /etc/passwd
mapping of user \s-1ID\s0s to names
.TP
name=\*`who am i | cut \-f1 \-d" "\*`
to set 
.B name
to current login
name.
.SH DIAGNOSTICS
.PP
.TP 1.25i
.I "line too long\^"
A line can have no more than 511 characters or fields.
.TP
.I "bad list for c\|/\|f option\^"
Missing 
.B \-c
or 
.B \-f
option or incorrectly specified
.IR list .
No error occurs if a line has fewer fields than the
.I list\^
calls for.
.TP
.I "no fields\^"
The
.I list\^
is empty.
.SH SEE ALSO
grep(1),
paste(1).
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