harvey/sys/man/1/field

.TH FIELD 1
.SH NAME
field \- extract fields from tabular data
.SH SYNOPSIS
.B field
[
.B -E
|
.B -e
]
[
.BI -F regexp
]
[
.B -0
|
.BI -O seperator
]
.I field list
[
.I file...
]
.SH DESCRIPTION
.I Field
extracts and reports fields from tabular data from files.  If no files are
specified, data is read from the standard input.  The file name `-' also
specifies the standard input.
.PP
The input field separator defaults to one or more whitespace
characters and can be set by the
.B -F
option.  The output field separator defaults to a single space character
and can be set to an arbitrary string by the
.B -O
option.  If the
.B -0
option is given, fields will be separated by a single NUL character
(binary zero).
.B -O
and
.B -0
are mutually exclusive.
.PP
.B Field
uses a heuristic to decide whether to include empty fields in the output:
if the delimiter is a single character, or a single escaped character, empty
fields will be included.  Otherwise, they will be collapsed and empty fields
at the beginning and end of a line will be ignored.  This behavior can be
overridden by the
.B -e
or
.B -E
options:
.B -e
will force eliding of empty fields and
.B -E
will force collapsing of empty fields.
.B -E
and
.B -e
are mutually exclusive.
.PP
Fields are selected by number, origin 1. Field 0 is the entire line.  Negative
fields count from the end of the line; thus, -1 is the last field.  The literal string
`NF' can also be given to specify the last field on the line.  Inclusive ranges of
fields can be given by joining the beginning and ending fields with a single `-'
character; if the second number is omitted it is assumed to be NF.
.PP
Multiple fields can be given, separated by whitespace, commas, or the
pipe character.
.PP
Fields can be repeated, and can be specified in arbitrary order.  For example:
.PP
.EX
	field -F: 2,1,-2-NF /adm/users
.EE
.SH SOURCE
.B /sys/src/cmd/field.c
.SH "SEE ALSO"
.IR awk (1),
.IR cut (1)
.SH BUGS
The range syntax only permits ascending ranges.