How do they do it???

This is the code from Turbo C 2.01's DIR.H file.

Code:

---

#if __STDC__
#define _Cdecl
#else
#define _Cdecl        cdecl
#endif

#if    !defined(__DIR_DEF_)
#define __DIR_DEF_

struct        ffblk        {
        char                ff_reserved[21];
        char                ff_attrib;
        unsigned        ff_ftime;
        unsigned        ff_fdate;
        long                ff_fsize;
        char                ff_name[13];
};

#define WILDCARDS 0x01
#define EXTENSION 0x02
#define FILENAME  0x04
#define DIRECTORY 0x08
#define DRIVE          0x10

#define MAXPATH  80
#define MAXDRIVE  3
#define MAXDIR          66
#define MAXFILE  9
#define MAXEXT          5

int        _Cdecl chdir                (const char *path);
int        _Cdecl findfirst        (const char *path, struct ffblk *ffblk,
                                int attrib);
int        _Cdecl findnext        (struct ffblk *ffblk);
void        _Cdecl fnmerge                (char *path,const char *drive,const char *dir,
                                const char *name, const char *ext);
int        _Cdecl fnsplit                (const char *path, char *drive, char *dir,
                                char *name, char *ext);
int        _Cdecl getcurdir        (int drive, char *directory);
char        *_Cdecl getcwd                (char *buf, int buflen);
int        _Cdecl getdisk                (void);
int        _Cdecl mkdir                (const char *path);
char        *_Cdecl mktemp                (char *template);
int        _Cdecl rmdir                (const char *path);
char        *_Cdecl searchpath        (const char *file);
int        _Cdecl setdisk                (int drive);

#endif

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How do they make all of the functions work :confused: Is there some secret that I don't know about?

I have no idea how much you know about programming, but do

you realise that this header file is used to create a table of calls

for the operating system to use to access a dll file with all the

definitions?

(I sorry if I am completly off target...) :)

then where does it tell the OS to make those calls? All that I see are definitions of dirves, etc. and definitions of funtions.

Hey, you sound like you know more than me. But in answer to the

question about the calls, the os uses the defs to map to the

address space of the dll module. In the source code that

accompanies this header, the function calls are made.


If that's not what you meant, I'm sorry, but that's all I know about

that area.

DLLs are in Windows, not DOS.

Quote:

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Originally posted by kinghajj
DLLs are in Windows, not DOS.

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The definitions in the header will be altered slightly (how so depends on if it's C or C++ and also the compiler) then they will map to a library file (usually with a .lib extension). It's the library that will probably house the code needed to perform these tasks