How to compile a C program in gcc which has header files?

Question

I want to compile a C program in gcc which has my 2 header files.

I am using the command:

gcc UDP_Receive.c -o UDP_Receive -lm

to compile it but I get an error stating "UDP_Data.h: No such file or directory"

How can I tell the compiler to include these header files?

Header Files:

#include "UDP_Data.h"

#include "Crypt.h"

Thanks, Ritesh

Dupe of http://stackoverflow.com/questions/973146/how-to-include-header-files-in-gcc-search-path — GrahamS, Mar 02 '11 at 10:01

Erik · Answer 1 · 2011-03-02T10:03:59.270

7

Use -Idirectory to add include paths, or make your #include statement use relative paths.

EDIT: Also be aware that #include filenames are case sensitive on many platforms.

EDIT2: Use #include "UDP_Data.h" not #include <UDP_Data.h>

edited Mar 02 '11 at 10:03

answered Mar 02 '11 at 09:29

Erik

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My header files are in the same location as my source code files. – Ritesh Banka Mar 02 '11 at 09:49
My header files are in the same location as my source code files. Could you please post a detailed example to walk me through the compilation process. Thanks – Ritesh Banka Mar 02 '11 at 09:51
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Is the filename exactly `UDP_Data.h`? Not e.g. `UDP_data.h`? – Erik Mar 02 '11 at 09:52
Yes, the file name is "UDP_Data.h" – Ritesh Banka Mar 02 '11 at 10:01
Are you using `#include ""` and not `#include <>`? – Erik Mar 02 '11 at 10:04
Yes, I am including the headers in "" – Ritesh Banka Mar 02 '11 at 10:15
Please edit your post and copy-paste any `#include` statements you have. – Erik Mar 02 '11 at 10:15
#include "UDP_Data.h" #include "Crypt.h" – Ritesh Banka Mar 02 '11 at 10:18
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According to the information you have given, this should work. If `UDP_Data.h` is in the same directory as `UDP_Receive.c`, and the filename is correct, this works. Doublecheck the filenames (look for hidden "weird" characters) both in the #include and the actual filename. – Erik Mar 02 '11 at 10:34

Skizz · Answer 2 · 2011-03-02T10:02:58.863

5

You have told the compiler to include that file, with a line like this:

#include "UDP_Data.h"

the problem is that the compiler can't find that file, and don't forget that some platforms are case sensitive when it comes to filenames so "UDP_data.h" is not the same file as "UDP_Data.h". The compiler will serach in a few places by default, but you will need to add extra directories to its search by using command line options. The exact option will depend on the compiler, for gcc it's:

-I<directory>

edited Mar 02 '11 at 10:02

answered Mar 02 '11 at 09:31

Skizz

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@Jim: How would you get that error if that line wasn't in the source file? (Apart from extra command line options of course!) – Skizz Mar 02 '11 at 10:01

How to compile a C program in gcc which has header files?

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