Each input-file is a file name or the hyphen-minus character “-” to indicate that standard input should be read. As usual, the argument “--” can be used in order to force interpretation of all remaining arguments as file names, even if an input-file argument begins with the hyphen-minus character.
In Pinyin, each syllable consists of one to six letters from the Latin alphabet; these letters comprise the fifty-two upper- and lowercase letters from the ASCII character set, plus the letter “U” with dieresis (umlaut) in both cases—in other words, the members of the set “[a–zA–ZüÜ]”.
In groff input, all ASCII letters are written as themselves. The “u with dieresis” can be written as “\[:u]” in lowercase or “\[:U]” in uppercase. Within .pinyin sections, gpinyin supports the form “ue” for lowercase and the forms “Ue” and “UE” for uppercase.
In a gpinyin source file, these tones are written by adding a numeral in the range 0 to 5 after the syllable. The tone numbers 1 to 4 are transformed into accents above vowels in the output. The tone numbers 0 and 5 are synonymous.
The following table summarizes the tones. Some output devices will not be able to render every output example.
The neutral tone number can be omitted from a word-final syllable, but not otherwise.
“Pinyin table” (Wikipedia),
Pinyin to Unicode,
On-line Chinese Tools,
Pinyin.info: a guide to the writing of Mandarin Chinese in romanization,
“Where do the tone marks go?” (Pinyin.info),
pinyin.txt from the CJK macro package for TeX,
pinyin.sty from the CJK macro package for TeX.
groff(1), grog(1), and groffer(1) explain how to view roff documents.
groff(7) and groff_char(7) are comprehensive references covering the language elements of GNU roff and the available glyph repertoire, respectively.