How to hg ignore filename with no extension?

Question

Mercurial can be configured to ignore files whose filename have a certain extension. For example, *.txt files can be ignored by adding this to ~/.hgignore:

syntax: glob
*.txt

How can I setup my .hgignore file to ignore files whose filenames have no extensions? For example, files named foobar and abracadabra should be ignored, but foobar.cpp and abracadabra.c should be tracked.

Answer 1

Use regexp syntax instead since it's not possible with glob:

syntax: regexp
^[^.]+$

PS: you can add it right after your syntax: glob section

Answer 2

If you have a small list of files without extension that you want to ignore, then you can just list them as glob patterns:

syntax: glob
foobar
abracadabra

If you want to ignore all files without an extension, then things become more difficult. If you use the regexp provided by zerkms,

syntax: regexp
^[^.]+$

then you will also ignore directories without an "extension", that is directories without . in their names such as src, and so on.

Because Mercurial matches files and directories top-down while traversing your working copy, and because it doesn't distinguish between files and directories when matching against the patterns in the .hgignore file, you cannot include a directory while ignoring files with the same name.

(You can simulate the opposite: by ignoring foobar/ in regexp syntax you end up ignoring all files inside foobar/ while not ignoring a file named foobar in another directory.)