C programming in a unix environment......?

Question

Hello

A friend of mine is learning C and she's doing so using a unix environment. I've taken some classes in C in the past and it was the norm to start any program with a library header, such as #include but none of her C programs using unix had any library header. Why is this?

Answer 1

You cannot execute a program without a header files or path to the header files. '#' mean search the current working directory and if not found the parent directory. So check the program it will have an absolute path of the header file something like C:\Programs\stdio.h.



If it still does not exist then it's the editor been used. You can set the relative path as part of the setting of the editor. However in commercial c programming, header files are mentioned in just one file and in all programs this file is mentioned as header file.



Hope this makes sense.



Good luck!

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Answer 2

Off the top of my head, two reasons I can think of:



- She's not referencing any symbols defined in external libraries/headers

- Her environment, or the script/command she uses to compile her code, is configured to automatically include a certain set of headers and link with the appropriate libraries



I suppose it's also possible her compiler isn't a standard C compiler, and is doing something clever.

Answer 3

Is it possible that the include files were generically included in one file. And that file was part of the make file or compilation script?



Without knowing the definition of the functions, C doesn't allow compilation to complete successfully.