sort – sort and/or merge files
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.
Compare as months.
The first three
non-white space characters
of the field
to upper case
Ignore leading white space (spaces and tabs) in field comparisons.
‘Phone directory’ order: only letters, accented letters, digits and white space are significant in comparisons.
Fold lower case letters onto upper case. Accented characters are folded to their non-accented upper case form.
Ignore characters outside the
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.
Reverse the sense of comparisons.
‘Tab character’ separating fields is
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:
Check that the single input file is sorted according to the ordering rules; give no output unless the file is out of sort.
Merge; assume the input files are already sorted.
Suppress all but one in each set of equal lines. Ignored bytes and bytes outside keys do not participate in this comparison.
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.
Put temporary files in
Print in alphabetical order all the unique spellings in a list of words where capitalized words differ from uncapitalized.
Print the users file sorted by user name (the second colon-separated field).
Print the first instance of each month in an already sorted file.
A stable sort: input lines that compare equal will come out in their original order.
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.