Hi, I found /usr/bin/checknr and tried it:
$ checknr /usr/share/man/man1/*.1 It spit out an enormous amount of error messages and crashed on 68 of the files. Its source code hasn't essentially been modified for 18 years, and the code still contains several out-of-bounds memory accesses, after some half-hearted attempts to fix them. Does anyone use this tool? Is it worth keeping? If it's worth keeping it, I could invest some time in making it bullet-proof, but I don't want to waste time like I did for indent(1). Roland