Ttgjyuk

Is there a command line program that takes a file containing English text, analyzes the text, and outputs its readability scores?

For example, if one feeds the program a text, the program should output the Flesch-Kincaid grade level, McLaughlin's SMOG grading, etc.

I believe such a program exists in the official repositories, but I cannot remember its name. There's also the possibility that I am misremebering.

The diction package contains a tool called style:

Style analyses the surface characteristics of the writing style of a
document. It prints
various readability grades, length of words, sentences and paragraphs. It can further
locate sentences with certain characteristics.

For example, if I evaluate your question body (saved in a file flux_question) to print the sentences with a readability index (ARI) over 10:

$ style -r 10 flux_question
flux_question:1: Is there a command line program that takes a file containing English text, analyzes the text, and outputs its readability scores?
flux_question:2: For example, if one feeds the program a text, the program should output the Flesch-Kincaid grade level, McLaughlin's SMOG grading, etc.
readability grades:
 Kincaid: 10.2
 ARI: 10.8
 Coleman-Liau: 12.5
 Flesch Index: 51.1/100
 Fog Index: 12.0
 Lix: 48.6 = school year 9
 SMOG-Grading: 11.2
sentence info:
 333 characters
 65 words, average length 5.12 characters = 1.65 syllables
 4 sentences, average length 16.2 words
 25% (1) short sentences (at most 11 words)
 0% (0) long sentences (at least 26 words)
 1 paragraphs, average length 4.0 sentences
 25% (1) questions
 25% (1) passive sentences
 longest sent 21 wds at sent 2; shortest sent 8 wds at sent 4
word usage:
 verb types:
 to be (1) auxiliary (2) 
 types as % of total:
 conjunctions 5% (3) pronouns 9% (6) prepositions 2% (1)
 nominalizations 0% (0)
sentence beginnings:
 pronoun (1) interrogative pronoun (0) article (0)
 subordinating conjunction (0) conjunction (0) preposition (0)

To filter the output you can use e.g. tail -n8 to get only the grades or grep 'Flesch|SMOG' to just print the Flesch Index and the SMOG-Grading:

$ style style_test | grep 'Flesch|SMOG'
 Flesch Index: 51.7/100
 SMOG-Grading: 11.2

Further reading

• man style


• linux.com article: Improve your writing with the GNU style checkers