SORT(1) BSD Reference Manual SORT(1)
sort - sort or merge text files
sort [-mubdfinrtx] [+pos1 [-pos2]] ... [-o output] [-T directory] [file]
The sort utility sorts text files by lines. Comparisons are based on one
or more sort keys (or fields) extracted from each line of input, and are
performed lexicographically. By default, if keys are not given, sort re-
gards each input line as a single field.
The following options are available:
-c Check that the single input file is sorted lexicographically. If
the file is not sorted, sort sorts it and writes the sorted out-
put to the standard output or the filename specified by the -o
-m Merge only; the input files are assumed to be pre-sorted.
The argument given is the name of an output file to be used in-
stead of the standard output. This file can be the same as one
of the input files.
The argument directory is used for creating temporary files.
-u Unique: suppress all but one in each set of lines having equal
keys. If used with the -c option, check that there are no lines
with duplicate keys.
The following options override the default ordering rules. When ordering
options appear independent of key field specifications, the requested
field ordering rules are applied globally to all sort keys.
-d Only blank space and alphanumeric characters are used in making
-f Considers all lowercase characters that have uppercase equiva-
lents to be the same for purposes of comparison.
-i Ignore all non-printable characters.
-n An initial numeric string, consisting of optional blank space,
optional minus sign, and zero or more digits (including decimal
point) is sorted by arithmetic value. The -n option implies the
-b option. (See below.) Note that the -b option is only effec-
tive when key fields have been specified and that -0 is consid-
ered equal to zero.
-r Reverse the sense of comparisons.
The treatment of field separators can be altered using the options:
-b Leading blank spaces are ignored when determining the starting
ending positions of a restricted sort key. If the -b option is
specified before the first +pos1 argument, it shall be applied to
all +pos1 arguments. Otherwise, the -b option can be attached
independently to each +pos1 or -pos2 argument (see below).
Char is used as the field separator character; char is not con-
sidered to be part of a field (although it can be included in a
sort key). Each occurrence of char is significant (for example,
``charchar'' delimits an empty field). If -t is not specified,
blank space characters are used as default field separators.
+pos1 Designates the start position of a key field.
-pos1 Designates the end position of a key field.
The following operands are available: file The pathname of a file to be
sorted, merged, or checked. If no file operands are specified, or if a
file operand is -, the standard input is used.
A field is defined as a minimal sequence of characters followed by a
field separator or a newline character. By default, the first blank
space of a sequence of blank spaces acts as the field separator. All
blank spaces in a sequence of blank spaces are considered to be part of
the next field; for example, all blank spaces at the beginning of a line
are considered to be part of the first field.
Fields are specified by the +pos1 and -pos2 arguments. A missing +pos1
argument defaults to the beginning of a line. A missing -pos2 argument
defaults to the end of a line.
The arguments +pos1 and -pos2 have the form m.n followed by one or more
of the options -b, -d, -f, -i, -n, -r. A +pos1 position specified by m.n
is interpreted to mean the nth character in the m+1th field. A missing
.n means `.0', indicating the first character of the m+1th field. If the
-b option is in effect, n is counted from the first non-blank character
in the m+1th field; m.0b refers to the first non-blank character in the
A -pos2 position specified by m.n is interpreted to mean the nth charac-
ter (including separators) after the last character of the mth field. A
missing .n means `.0', indicating the last character of the mth field.
If the -b option is in effect, n is counted from the last leading blank
character in the m+1th field; m.1b refers to the first non-blank charac-
ter in the m+1th field.
/var/tmp/stm*, /tmp/* Default temporary directories (in order
comm(1), uniq(1), join(1)
Lines which are longer than 4096 are discarded and processing continues.
A sort command appeared in Version 6 AT&T UNIX.
4.4BSD May 4, 1995 2