Most C programmers use a .c file name extension for executable C source code, and .h or no filename extension at all for source files containing definitions and interface specifications, so-called header files.
Some C compilers inspect the file name extension and draw conclusions, but most will accept almost any filename convention.
Other common filename extensions used in the C family of programming languages are .cpp and .hpp (C++) and .cs (C#). On operating systems with case-sensitive file names, these extensions are generally expected to be in lower case.
David Spuler has written: 'Comprehensive C' -- subject(s): C (Computer program language) 'C++ and C efficiency' -- subject(s): C++ (Computer program language), C (Computer program language)
The extension of c program is ".c".
Conor Sexton has written: 'Newnes C++ pocket book' -- subject(s): C (Computer program language), C++ (Computer program language) 'C pocket book' -- subject(s): C (Computer program language) 'Y2K7'
Robert C. Seacord has written: 'Secure coding in C and C++' -- subject(s): C (Computer program language), C++ (Computer program language), Computer security
Yes, PGP is written in C-language.
Steve Schustack has written: 'C for fun and profit' -- subject(s): C (Computer program language) 'Variations in C' -- subject(s): C (Computer program language) 'C for fun and profit' -- subject(s): C (Computer program language) 'Variations In C Edition'
Jeri R. Hanly has written: 'Essential C[plus plus]for engineers and scientists' -- subject(s): C (Computer program language) 'Essential C++ for engineers and scientists' -- subject(s): C++ (Computer program language), C (computer program language)
Robert C. Hutchison has written: 'Programming using the C language' -- subject- s -: C - Computer program language -
Eric P. Bloom has written: 'The Turbo C++ trilogy' -- subject(s): C (Computer program language), C++ (Computer program language), Turbo C (Computer file), Turbo C++ 'Turbo C Plus Plus Trilogy' 'The C trilogy' -- subject(s): C (Computer program language)
C. T. Zahn has written: 'C notes, a guide to the C programming language' -- subject(s): C (Computer program language)
T. D. Brown has written: 'C for Pascal programmers' -- subject(s): C (Computer program language) 'C for FORTRAN programmers' -- subject(s): C (Computer program language)
Joseph. Bergin has written: 'Data structure programming' -- subject(s): C (Computer program language), C++ (Computer program language), Data structures (Computer science), Standard template library 'Data abstraction' -- subject(s): Object-oriented programming (Computer science), C++ (Computer program language), C (Computer program language)