PWB1/usr/man/man1/sort.1

.th SORT I 5/31/77
.sh NAME
sort \*- sort or merge files
.sh SYNOPSIS
.bd sort
[
.bd \*-mubdfinr
] [
.bd \*-t\c
x ]
[ \fB+\fRpos [ \fB\*-\fRpos ]
] ...
[
.bd \*-o
name ] [ name ] ...
.sh DESCRIPTION
.it Sort
sorts
lines of all the named files together
and writes the result on
the standard output.
The name `\*-' means
the standard input.
The standard input is also used if no input file names are given.
Thus
.it sort
may be used as a filter.
.s3
The default sort key is an entire line.
Default ordering is
lexicographic by bytes in machine
collating sequence.
The ordering is affected by the following flags
one or more of which may appear.
.s3
.lp +4 4
\fBb\fR	Leading blanks (spaces and tabs) are not included in keys.
.lp+4 4
\fBd\fR	`Dictionary' order: only letters, digits and blanks
are significant in comparisons.
.lp +4 4
\fBf\fR	Fold lower case
letters onto upper case.
.lp +4 4
\fBi\fR	Ignore all nonprinting nonblank characters in nonnumeric comparisons.
.lp +4 4
\fBn\fR	An initial numeric string,
consisting of optional minus sign,
digits and optionally included decimal point,
is sorted by arithmetic value.
.lp+4 4
\fBr\fR	Reverse the sense of comparisons.
.lp +4 4
\fBt\fIx\fR	Tab character between fields is
.it x.
.s3
.i0
Selected parts of the line, specified by
\fB+\fIpos\fR
and
\fB\*-\fIpos\fR,
may be used as sort keys.
.it Pos
has the form
.it m.n
optionally followed by one or more of the flags
.bd bdfinr,
where
.it m
specifies a number of fields to skip,
.it n
a number of characters to skip further into the next field,
and the flags specify a special ordering rule for the key.
A missing
.bd \&.\c
.it n
is taken to be 0.
\fB+\fIpos\fR denotes the beginning of the key;
\fB\*-\fIpos\fR denotes the first position after the key
(end of line by default).
Later keys are compared only when all earlier keys
compare equal.
.s3
When no tab character has been specified,
a field consists of
nonblanks and any preceding blanks.
Under the
.bd \*-b
flag, leading blanks are excluded from a field.
When a tab character has been specified,
fields are strings separated by tab characters.
.s3
.i0
Lines that otherwise compare equal are ordered
with all bytes significant.
.s3
These flag arguments are also understood:
.s3
.lp +4 4
\fBm\fR	Merge only, the input files are already sorted.
.s3
.lp +4 4
\fBo\fR	The next argument is the name of an output file
to use instead of the standard output.
This file may be the same as one of the inputs,
except under the merge flag \fB\*-m\fR.
.s3
.lp +4 4
\fBu\fR	Suppress all but one in each
set of contiguous equal lines.
Ignored bytes
and bytes outside keys
do not participate in
this comparison.
.i0
.s3
Examples.
Print a list of all the distinct
.it roff\^\c
(I) commands in a given document:
.s3
.ti +8
grep "^\\." document
.tr ||
.if t \(bv
.if n |
sort \*-u +0 \*-0.3
.s3
Print the password file
.it passwd\^\c
(V) sorted by user id:
.s3
.ti +8
sort \*-t: +2n /etc/passwd
.sh FILES
/tmp/stm???