$ coreutils --help sort
sort-about
Usage: sort-usage
Arguments:
[files]...
Options:
--help
sort-help-help
--version
sort-help-version
--sort <sort>
[possible values: general-numeric, human-numeric, month, numeric, version,
random]
-h, --human-numeric-sort
sort-help-human-numeric
-M, --month-sort
sort-help-month
-n, --numeric-sort
sort-help-numeric
-g, --general-numeric-sort
sort-help-general-numeric
-V, --version-sort
sort-help-version-sort
-R, --random-sort
sort-help-random
--random-source <FILE>
sort-help-random-source
-d, --dictionary-order
sort-help-dictionary-order
-m, --merge
sort-help-merge
-c, --check[=<check>...]
sort-help-check [possible values: silent, quiet, diagnose-first]
-C, --check-silent
sort-help-check-silent
-f, --ignore-case
sort-help-ignore-case
-i, --ignore-nonprinting
sort-help-ignore-nonprinting
-b, --ignore-leading-blanks
sort-help-ignore-leading-blanks
-o, --output <FILENAME>
sort-help-output
-r, --reverse
sort-help-reverse
-s, --stable
sort-help-stable
-u, --unique
sort-help-unique
-k, --key <key>
sort-help-key
-t, --field-separator <field-separator>
sort-help-separator
-z, --zero-terminated
sort-help-zero-terminated
--parallel <NUM_THREADS>
sort-help-parallel
-S, --buffer-size <SIZE>
sort-help-buf-size
-T, --temporary-directory <DIR>
sort-help-tmp-dir
--compress-program <PROG>
sort-help-compress-prog
--batch-size <N_MERGE>
sort-help-batch-size
--files0-from <NUL_FILE>
sort-help-files0-from
--debug
sort-help-debug
sort-after-help
GNU does same things with
coreutils --help.