Shell command: sort

sort sorts lines of text files.

sort is especially useful in conjunction with uniq (because uniq needs the input lines to be sorted).

However, the traditional sequence sort | uniq can nowadays usually be abbreviavated with sort -u

Options

Options controlling sorting

`-b`	`--ignore-leading-blanks`		ignore leading blanks
`-d`	`--dictionary-order`		consider only blanks and alphanumeric characters
`-f`	`--ignore-case`		fold lower case to upper case characters
`-g`	`--general-numeric-sort`		compare according to general numerical value
`-i`	`--ignore-nonprinting`		consider only printable characters
`-M`	`--month-sort`		compare (unknown) < 'JAN' < ... < 'DEC'
`-h`	`--human-numeric-sort`		compare human readable numbers (e.g., 2K 1G)
`-n`	`--numeric-sort`		compare according to string numerical value
`-R`	`--random-sort`		Shuffle, but group identical keys. See also `shuf(1)`
	`--random-source`	`=FILE`	get random bytes from `FILE`
`-r`	`--reverse`		reverse the result of comparisons
	`--sort`	`=WORD`	sort according to `WORD`. General-numeric `-g`, human-numeric `-h`, month `-M`, numeric `-n`, random `-R`, version `-V`
`-V`	`--version-sort`		natural sort of (version) numbers within text. Compare `ls -v`

Other options

	`--batch-size`	`=NMERGE`	merge at most `NMERGE` inputs at once; for more use temp files
`-c`	`--check`	`=diagnose-first`	Check for sorted input; do not sort
`-C`	`--check=quiet`		Like `-c`, but do not report first bad line (compare `--check=silent`)
	`--compress-program`	`=PROG`	compress temporaries with `PROG`; decompress them with `PROG -d`
	`--debug`		annotate the part of the line used to sort, and warn about questionable usage to stderr
	`--files0-from`	`=F`	Read input from the files specified by NUL-terminated names in file `F`; If `F` is `-` then read names from stdin.
`-k`	`--key`	`=KEYDEF`	Sort via a key; `KEYDEF` gives location and type
`-m`	`--merge`		merge already sorted files; do not sort
`-o`	`--output`	`=FILE`	write result to `FILE` instead of stdout
`-s`	`--stable`		stabilize sort by disabling last-resort comparison
`-S`	`--buffer-size`	`=SIZE`	use `SIZE` for main memory buffer
`-t`	`--field-separator`	`=SEP`	use `SEP` instead of non-blank to blank transition
`-T`	`--temporary-directory`	`=DIR`	use `DIR` for temporaries, not `$TMPDIR` or `/tmp`; multiple options specify multiple directories
	`--parallel`	`=N`	change the number of sorts run concurrently to `N`
`-u`	`--unique`		with `-c`, check for strict ordering; without `-c`, output only the first of an equal run. Compare with `uniq`
`-z`	`--zero-terminated`		line delimiter is `NUL`, not newline
	`--help`
	`--version`

In place sorting

The -o flag specifies an output file name for the sorted file.

If the specified file name is equal to the sorted file, this file will then have the sorted content.

cat > to-be-sorted <<"EOF"
one
two
three
four
five
EOF

sort to-be-sorted -o to-be-sorted

cat to-be-sorted

Github repository shell-commands, path: /sort/o_in-place

-n: sort numerically

With -n, sort sorts values numerically rather than alphabetically.

Without this flag, sort considers 123 to be smaller than 89.

-h: sort human readable numbers

-h causes the sorted values to be interpreted as human readable, for example 1.89G or 815M.

Incidentally, ls also has an -h flag which reports file sizes human readable.

Thus the output of ls with the -h flag can be piped in sort with the -h flag to show a directory's largest files with file sizes human readable.

-k: keydef

-k allows to define a start and optional stop position:

-k startpos[,stoppos]

The format of startpos and stoppos is F[.C][OPTS]:

`F`	Field number
`C`	Character pos in the field
`OPTS`	a series of single-letter ordering options

Locale

The sort order is influenced by the current locale in effect.

«Traditional» sort order (i. e. sorting by byte value) can be achieved by setting LC_ALL to C.

Strange results

Use the --debug option.

Environment variables

LC_CTYPE