sort.1

<B>Digital的Unix操作系统VAX 4.2源码</B>

.\" SCCSID: @(#)sort.1	8.1	9/11/90
.TH sort 1
.SH Name
sort \- sort file data
.SH Syntax
.B sort
[\|\fIoptions\fR\|] [\|\fB\-k \fIkeydef\fR\|] 
[\fB+\fIpos1\fR\|[\fB\-\fIpos2\fR\|]\|] [\|\fIfile\fR...\|] 
.SH Description
.NXR "sort command"
.NXR "file" "comparing"
.NXR "file" "merging"
.NXR "file" "sorting"
.NXA "sort command" "look command"
.NXA "sort command" "uniq command"
The
.PN sort
command
sorts lines of all the named files together and writes the result on
the standard output.  The name `\-' means the standard input.
If no input files are named, the standard input is sorted.
.SH Options
.NXR "sort command" "options"
The default sort key is an entire line.
Default ordering is lexicographic
by bytes in machine collating sequence.
The ordering is affected globally by the following options,
one or more of which may appear.
.IP \fB\-b\fR 12
Ignores leading blanks (spaces and tabs) in field comparisons.
.IP \fB\-d\fR
Sorts data according to dictionary ordering:  letters, digits, and blanks only.  
.IP \fB\-f\fR
Folds uppercase to lowercase while sorting.  
.IP \fB\-i\fR
Ignore characters outside the ASCII range
040-0176 in nonnumeric comparisons.
.IP "\-k \fIkeydef\fR"
The \fIkeydef\f argument is a key field definition. The format is
.IR field_start ,
[\fIfield_end\fP] [\fItype\fP], where
.I field_start
and
.I field_end
are the definition of the restricted search key, and 
.I type
is a modifier from the option list [bdfinr]. These modifiers have
the functionality, for this key only, that their 
command line counter-parts have for the entire record.
.IP \fB\-n\fR
Sorts fields with numbers numerically.  
An initial numeric string,
consisting of optional blanks, optional minus sign,
and zero or more digits with optional decimal point,
is sorted by arithmetic value.  
(Note that \-0 is taken to be equal to 0.)
Option
.B n
implies option
.B b.
.IP \fB\-r\fR
Reverses the sense of comparisons.
.IP \fB\-t\fIx\fR 
Uses specified character as field separator.  
.PP
The notation
.BI + "pos1 " "\-\fIpos2"
restricts a sort key to a field beginning at
.I pos1
and ending just before
.IR pos2 .
.I Pos1
and
.I pos2
each have the form
.IB m . n\fR,
optionally followed by one or more of the options
.B bdf\&inr,
where
.I m
tells a number of fields to skip from the beginning of the line and
.I n
tells a number of characters to skip further.
If any options are present they override all the global
ordering options for this key.  If the
.B b
option is in effect
.I n
is counted from the first nonblank in the field;
.B b
is attached independently to 
.IR pos2 .
A missing \&\fB.\fIn\fR means .0; a missing
.BI \- pos2
means the end of the line.  Under the
.BI \-t x
option, fields are strings separated by
.IR x ;
otherwise fields are nonempty nonblank strings separated by blanks.
.PP
When there are multiple sort keys, later keys
are compared only after all earlier keys compare equal.
Lines that otherwise compare equal are
ordered with all bytes significant.
.PP
These are additional options:
.IP \fB\-c\fR 12
Checks sorting order and displays output only if out of order.  
.IP \fB\-m\fR 
Merges previously sorted data.  
.IP "\fB\-o \fIname\fR"
Uses specified file as output file.  
This file may be the same as one of the inputs.
.IP "\fB\-T \fIdir\fR"
Uses specified directory to build temporary files.  
.IP \fB\-u\fR
Suppresses all duplicate entries.  
Ignored bytes and bytes outside
keys do not participate in this comparison.
.SH Examples
.NXR(e) "sort command"
.PP
Print in alphabetical order all the unique spellings in a list of words.
Capitalized words differ from uncapitalized.
.EX
.ti +8
sort \-u +0f +0 list
.EE
.PP
Print the password file, 
sorted by user id number (the 3rd colon-separated field).
.EX
.ti +8
sort \-t: +2n /etc/passwd
.EE
.PP
Print the first instance of each month in an already sorted file
of (month day) entries.
The options
.B \-um
with just one input file make the choice of a
unique representative from a set of equal lines predictable.
.EX
.ti +8
sort \-um +0 \-1 dates
.EE
.SH Restrictions
.NXR "sort command" "restricted"
Very long lines are silently truncated.
.SH Diagnostics
.NXR "sort command" "diagnostics"
Comments and exits with nonzero status for various trouble
conditions and for disorder discovered under option
.BR c .
.SH Files
/usr/tmp/stm*, /tmp/*	first and second tries for
temporary files
.SH See Also
comm(1), join(1), rev(1), uniq(1)