DragonFly On-Line Manual Pages
STYLE(1) User commands STYLE(1)
style - analyse surface characteristics of a document
style [-L language] [-l length] [-r ari] [file...]
style [--language language] [--print-long length] [--print-ari ari]
Style analyses the surface characteristics of the writing style of a
document. It prints various readability grades, length of words, sen-
tences and paragraphs. It can further locate sentences with certain
characteristics. If no files are given, the document is read from
Numbers are counted as words with one syllable. A sentence is a
sequence of words, that starts with a capitalised word and ends with a
full stop, double colon, question mark or exclamation mark. A single
letter followed by a dot is considered an abbreviation, so it does not
end a sentence. Various multi-letter abbreviations are recognized,
they do not end a sentence as well. A paragraph consists of two or
more new line characters.
Style understands cpp(1) #line lines for being able to give precise
locations when printing sentences.
The Kincaid Formula has been developed for Navy training manu-
als, that ranged in difficulty from 5.5 to 16.3. It is probably
best applied to technical documents, because it is based on
adult training manuals rather than school book text. Dialogs
(often found in fictional texts) are usually a series of short
sentences, which lowers the score. On the other hand, scien-
tific texts with many long scientific terms are rated higher,
although they are not necessarily harder to read for people who
are familiar with those terms.
Kincaid = 11.8*syllables/wds+0.39*wds/sentences-15.59
Automated Readability Index
The Automated Readability Index is typically higher than Kincaid
and Coleman-Liau, but lower than Flesch.
ARI = 4.71*chars/wds+0.5*wds/sentences-21.43
The Coleman-Liau Formula usually gives a lower grade than Kin-
caid, ARI and Flesch when applied to technical documents.
Coleman-Liau = 5.88*chars/wds-29.5*sent/wds-15.8
Flesh reading easy formula
The Flesh reading easy formula has been developed by Flesh in
1948 and it is based on school text covering grade 3 to 12. It
is wide spread, especially in the USA, because of good results
and simple computation. The index is usually between 0 (hard)
and 100 (easy), standard English documents averages approxi-
mately 60 to 70. Applying it to German documents does not
deliver good results because of the different language struc-
Flesch Index = 206.835-84.6*syll/wds-1.015*wds/sent
The Fog index has been developed by Robert Gunning. Its value
is a school grade. The ``ideal'' Fog Index level is 7 or 8. A
level above 12 indicates the writing sample is too hard for most
people to read. Only use it on texts of at least hundred words
to get meaningful results. Note that a correct implementation
would not count words of three or more syllables that are proper
names, combinations of easy words, or made three syllables by
suffixes such as -ed, -es, or -ing.
Fog Index = 0.4*(wds/sent+100*((wds >= 3 syll)/wds))
The Lix formula developed by Bjornsson from Sweden is very sim-
ple and employs a mapping table as well:
Lix = wds/sent+100*(wds >= 6 char)/wds
Index 34 38 41 44 48 51 54 57
School year 5 6 7 8 9 10 11
The SMOG-Grading for English texts has been developed by
McLaughlin in 1969. Its result is a school grade.
SMOG-Grading = square root of (((wds >= 3 syll)/sent)*30) + 3
It has been adapted to German by Bamberger & Vanecek in 1984,
who changed the constant +3 to -2.
The word usage counts are intended to help identify excessive use of
particular parts of speech.
The category of verbs labeled "to be" identifies phrases using
the passive voice. Use the passive voice sparingly, in favor of
more direct verb forms. The flag -p causes style to list all
occurrences of the passive voice.
The verb category "aux" measures the use of modal auxiliary verbs, such
as "can", "could", and "should". Modal auxiliary verbs modify the mood
of a verb.
The conjunctions counted by style are coordinating and subordi-
nating. Coordinating conjunctions join grammatically equal sen-
tence fragments, such as a noun with a noun, a phrase with a
phrase, or a clause to a clause. Coordinating conjunctions are
"and," "but," "or," "yet," and "nor."
Subordinating conjunctions connect clauses of unequal status. A subor-
dinating conjunction links a subordinate clause, which is unable to
stand alone, to an independent clause. Examples of subordinating con-
junctions are "because," "although," and "even if."
Pronouns are contextual references to nouns and noun phrases.
Documents with few pronouns generally lack cohesiveness and flu-
idity. Too many pronouns may indicate ambiguity.
Nominalizations are verbs that are changed to nouns. Style rec-
ognizes words that end in "ment," "ance," "ence," or "ion" as
nominalizations. Examples are "endowment," "admittance," and
"nominalization." Too much nominalization in a document can
sound abstract and be difficult to understand. The flag -N
causes style to list all nominalizations. The flag -n prints
all sentences with either the passive voice or a nominalization.
-L language, --language language
set the document language (de, en, nl).
-l length, --print-long length
print all sentences longer than length words.
-r ari, --print-ari ari
print all sentences whose readability index (ARI) is greater
-p passive, --print-passive
print all sentences phrased in the passive voice.
-N nominalizations, --print-nom
print all sentences containing nominalizations.
-n nominalizations-passive, --print-nom-passive
print all sentences phrased in the passive voice or containing
Print a short usage message.
Print the version.
On usage errors, 1 is returned. Termination caused by lack of memory
is signalled by exit code 2.
specifies the default document language. The default language
specifies the document character set. The default character set
This program is GNU software, copyright 1997-2007 Michael Haardt
It contains contributions by Jason Petrone <firstname.lastname@example.org>, Uschi
Stegemeier <email@example.com> and Hans Lodder.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MER-
CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details.
You should have received a copy of the GNU General Public License along
with this program. If not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
There has been a style command on old UNIX systems, which is now part
of the AT&T DWB package. The original version was bound to roff by
enforcing a call to deroff.
Cherry, L.L.; Vesterman, W.: Writing Tools--The STYLE and DICTION pro-
grams, Computer Science Technical Report 91, Bell Laboratories, Murray
Hill, N.J. (1981), republished as part of the 4.4BSD User's Supplemen-
tary Documents by O'Reilly.
Coleman, M. and Liau,T.L. (1975). 'A computer readability formula
designed for machine scoring', Journal of Applied Psychology, 60(2),
GNU August 30th, 2007 STYLE(1)