Draft pkgdatadir_r(filename) relocation function.

[John McCabe-Dansted]

Hi, I bashed out this code on the bus. What do you think of the style?

* Should I replace the calls the vasnprintf with calls to
xmalloc,strlen and strcat?
* should
 static fn_full_data_dir=NULL;
be
 static fn_full_data_dir[PATH_MAX];

BTW, PATH_MAX is only a soft limit on Windows NT onwards. Paths of
length 4096 and possibly more are supported.

---

/* a stub so the test harness compiles on linux, at least */

#define PKGDATADIR "/usr/share"

/* header */

#if defined _WIN32 || defined __WIN32__
#define PKGDATADIR_R(s) (pkgdatadir_r(s))
#else
#define PKGDATADIR_R(s) (PKGDATADIR s)
#endif

/* C-code */

#if defined _WIN32 || defined __WIN32__

static fn_full_data_dir=NULL;
static static_fullpath=NULL;

void set_prefix_from_argv0(const char *argv0) {
        char *bin_dir;
        char *data_dir;
        char full_data_dir[PATH_MAX];

        bin_dir=dir_name(argv0);
        
        data_dir=xvasprintf("%s%s",bin_dir,"..\\share");

        free(bin_dir);
        if (GetFullPathName(data_dir,PATH_MAX,full_data_dir,NULL))
                fn_full_data_dir=xstrcpy(full_data_dir);
        else
                fn_full_data_dir=xstrcpy(data_dir);
        free(data_dir);
}

char* pkgdatadir_r(const char *filename)
{
        ASSERT(fn_full_data_dir!=NULL);

        if (static_fullpath!=NULL)
               free(static_fullpath);

        static_fullpath=xvasprintf("%s%s",fn_full_data_dir,filename);

        return (static_fullpath);
}

#endif /*defined _WIN32 || defined __WIN32__*/

/* test harness */

int main(int argc, char **argv) {
#if defined _WIN32 || defined __WIN32__
       set_prefix_from_argv0(argv[0]);
#endif
        puts(PKGDATADIR_R("/testfile.txt"));
        return 0;
}

--
John C. McCabe-Dansted
PhD Student
University of Western Australia