sort – sort and/or merge files|
sort [ −cmuMbdfinrwtx ] [ +pos1 [ −pos2 ] ... ] ... [ −k pos1
[ ,pos2 ] ] ...|
’ [ −o output ] [ −T dir ... ] [ option ... ] [ file ... ]|
Sort sorts lines of all the files together and writes the result
on the standard output. If no input files are named, the standard
input is sorted.
The default sort key is an entire line. Default ordering is lexicographic
by runes. The ordering is affected globally by the following options,
one or more of which may appear.|
−M Compare as months. The first three non-white space characters
of the field are folded to upper case and compared so that JAN
precedes FEB, etc. Invalid fields compare low to JAN.
−b Ignore leading white space (spaces and tabs) in field comparisons.
−d ‘Phone directory’ order: only letters, accented letters, digits
and white space are significant in comparisons.
−f Fold lower case letters onto upper case. Accented characters
are folded to their non-accented upper case form.
−i Ignore characters outside the ASCII range 040-0176 in non-numeric
−w Like −i, but ignore only tabs and spaces.
−n An initial numeric string, consisting of optional white space,
optional plus or minus sign, and zero or more digits with optional
decimal point, is sorted by arithmetic value.
−g Numbers, like −n but with optional e-style exponents, are sorted
−r Reverse the sense of comparisons.
−tx ‘Tab character’ separating fields is x.
The notation +pos1 −pos2 restricts a sort key to a field beginning
at pos1 and ending just before pos2. Pos1 and pos2 each have the
form m.n, optionally followed by one or more of the flags Mbdfginr,
where m tells a number of fields to skip from the beginning of
the line and n tells a number of characters to skip further. If
any flags are present they
override all the global ordering options for this key. A missing
.n means .0; a missing −pos2 means the end of the line. Under
the −tx option, fields are strings separated by x; otherwise fields
are non-empty strings separated by white space. White space before
a field is part of the field, except under option −b. A b flag
may be attached
independently to pos1 and pos2.
The notation −k pos1[,pos2] is how POSIX sort defines fields:
pos1 and pos2 have the same format but different meanings. The
value of m is origin 1 instead of origin 0 and a missing .n in
pos2 is the end of the field.
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.
These option arguments are also understood:
−c Check that the single input file is sorted according to the
ordering rules; give no output unless the file is out of sort.
−m Merge; assume the input files are already sorted.
−u Suppress all but one in each set of equal lines. Ignored bytes
and bytes outside keys do not participate in this comparison.
−o 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
−Tdir Put temporary files in dir rather than in /var/tmp.
sort −u +0f +0 list|
sort −t: +1 /adm/users
Print in alphabetical order all the unique spellings in a list
of words where capitalized words differ from uncapitalized.|
sort −umM dates
Print the users file sorted by user name (the second colon-separated
grep −n '^' input | sort −t: +1f +0n | sed 's/[0−9]*://'
Print the first instance of each month in an already sorted file.
Options −um with just one input file make the choice of a unique
representative from a set of equal lines predictable.|
A stable sort: input lines that compare equal will come out in
their original order.|
Sort comments and exits with non-null status for various trouble
conditions and for disorder discovered under option −c.|
An external null character can be confused with an internally
generated end-of-field character. The result can make a sub-field
not sort less than a longer field.
Some of the options, e.g. −i and −M, are hopelessly provincial.|