[madhouse]

You can limit your search to certain repositories on GitHub, with advanced search: https://github.com/search/advanced

You will need to enter the repositories by hand, though. Mind you, writing a small tool that'd list the most popular/forked/starred/etc C repos, and do a search for you in those should be a few minute task.

[cweagans]

Couldn't you just ask for repos with > 5-10 stars instead of maintaining a list of popular C projects?

[zb3]

The whole point was that I cannot specify this criteria when searching for code. This option is for repository search only.

Searching: "typedef struct language:C stars:>100" doesn't do the job.