I'm interested in whether publishing _AM_PROG_TAR in tar.m4 Well, I agree with Bob that _AM_PROG_TAR is rather idiosyncratic, what with defining commands that output the tar file to stdout. But nevertheless, I take your point that copying all the checks is rather annoying. Users can set the TAR envvar (and/or AMTAR, maybe) to get a different program, I believe.
To be public and documented, I think I'd want to rename it to, say, AM_PROG_TAR_STDOUT (or something even weirder), so users don't just blindly think they're checking for a tar program like other AM_PROG_foo functions. At any rate, I have no ETA on the next Automake release, and I doubt it will be any time soon, and may or may not include this change. If you or someone else would like to make a patch for it, that would be great. _AM_PROG_TAR should then simply become a call to the public fn. (I would not want to remove it.) Meanwhile, you could use _AM_PROG_TAR despite the leading _. I can't imagine its interface will ever change. Even the implementation hasn't changed in several years. Thanks for the suggestion, Karl
