ssort - Suffix-sorting CLI tool

ssort is a CLI sort utility for inverse lexicographic (suffix) sorting.

An inverse/suffix sort order looks at the last character first, and works backwards towards the first.

ssort is designed to be fast. Typically it can process 1M lines of text in a matter of seconds. Some options may make it somewhat slower (e.g. --stable).

ssort -h

Usage: ssort [OPTIONS] [FILE]...

Arguments:
  [FILE]...  input files (use '-' for stdin, default if no files provided)

Options:
  -h, --help     Print help (see more with '--help')
  -V, --version  Print version

Sorting Options:
  -i, --ignore-case       ignore case when sorting
  -l, --line              use entire line for sorting instead of first word
  -d, --dictionary-order  dictionary order: ignore non-alphabetic characters when finding first word
  -r, --reverse           reverse the sort order
  -s, --stable            stable sort (maintains original order of equal elements)
  -n, --normalize         normalize unicode to NFC form

Output:
  -a, --right-align      right-align output by adding leading spaces
  -x, --exclude-no-word  exclude lines without words
  -w, --word-only        output only the word used for sorting (excludes the remainder of lines)

Basic behavior

The CLI tool feels very much like the standard sort utility, with the only notable exception that the short option for --ignore-case is not -f but the more intuitive -i.

If given an argument, ssort will take it as a file path:

$ ssort tests/test1.txt
a
aa
ba
za
b
ab
ac
bc
abc
z
az
bz
zz
zzz

Without arguments, ssort takes input from stdin. The above is therefore equivalent to:

$ cat tests/test1.txt | ssort
...

Options

--right-align / -a

In order to make the comparisons easier on the eye, use the -a option, which right-aligns the results:

$ ssort -a tests/test1.txt
  a
 aa
 ba
 za
  b
 ab
 ac
 bc
abc
  z
 az
 bz
 zz
zzz

By default, ssort uses the first word on the line for sorting and ignores the rest of the line:

$ cat tests/test2.txt
a zzz
aa bbb
ab xxxxx
b aaa
za -

$ ssort -a tests/test2.txt
 a zzz
aa bbb
za -
 b aaa
ab xxxxx

--line / -l

With the -l/--line option, the text is sorted using entire lines:

$ ssort -al tests/test2.txt
	za -
   b aaa
  aa bbb
ab xxxxx
   a zzz

--dictionary-order / -d

The -d option ignores any non-alphabetic characters in identifying the first word. It has no effect in combination with the --line option.

--word-only / -w

The -w option outputs only the word used in the sort, dropping the remainder of lines. It has no effect in combination with --line.

--exclude-no-word / -x

The -x option removes empty lines and lines without any alphanumeric characters from the output. It has no effect in combination with -l.