hyphen [ File ... ]
The hyphen command reads one or more English-language files, finds all the lines ending with hyphenated words, and writes those words to standard output. The parameter File specifies English-language files to be read by the hyphen command. The default is standard input. If no file is specified or if the - (hyphen) is specified as the last file name, the hyphen command reads standard input. The hyphen command can be used as a filter.
Note: The hyphen command cannot read hyphenated words that are italic or underlined. The hyphen command sometimes gives unnecessary output.
To check the hyphenation performed by a text-formatting program on a file, enter:
mm [Flag...] [File...] | hyphen
The mm command, troff command.