“Pretty much everything on the web uses those two things: C and UNIX,” Pike tells Wired. “The browsers are written in C. The UNIX kernel — that pretty much the entire Internet runs on — is written in C. Web servers are written in C, and if they’re not, they’re written in Java or C++, which are C derivatives, or Python or Ruby, which are implemented in C. And all of the network hardware running these programs I can almost guarantee were written in C. Ritchie lived in a very different time and worked in a very different environment than someone like Jobs. It only makes sense that he wouldn’t get his due. But those who matter understand the mark he left. “There’s that line from Newton about standing on the shoulders of giants,” says Kernighan. “We’re all standing on Dennis’ shoulders.”

Ever wondered what the numbers after the chmod command actually mean?

There are always three numbers (in this case 7, 6, and 0).

• The first number designates the permissions for the owner of the file/directory.
• Second is the owning group.
• Third is everyone else.

Each number is really three bits, rwx. Just read permissions is the bits 100 (4), just write is 010 (2), just execute 001 (1). If you want to give execute and read you add execute and read together and you get 5. If you want to give both read and write it would be 6, and so on.

So, for example 760 is read, write and execute for the owner, read and write for the owning group and all other users have no access.