loading cygwin1.dll at runtime

Fri May 16 21:59:00 GMT 2003

Hi,
I want to add the following feature to an application compiled with
-mno-cygwin:
 Every time the application is about to make a system call with a
 pathname as argument the application should convert the (possibly
 cygwin/unix) path to the corresponding windows path using
 cygwin_conv_to_full_win32_path provided by cygwin1.dll, but only if
 cygwin1.dll is present on the current host.
In order to do that I need to link cygwin1.dll at runtime and get a
pointer to cygwin_conv_to_full_win32_path. I tried to do this by just
using LoadLibrary/GetProcAddress/FreeLibrary provided by Windows.
However, the application crashes. Gdb tells:
 Program received signal SIGSEGV, Segmentation fault.
 0x61051931 in getpass ()
 (gdb) bt
 #0 0x61051931 in getpass ()
 #1 0x6104f268 in getpass ()
 #2 0x61056629 in cygwin_conv_to_full_win32_path ()
 #3 0x00401423 in main (argc=2, argv=0x3f24e8) at t.c:21
Maybe I am missing a call to an initialization routine. Here is a
complete compilable example:
 #include <stdio.h>
 #include <Windows.h>
 
 typedef void (*conv_fun_t) (const char*, char*);
 
 int main(int argc, char* argv[])
 {
 if (argc!=2) { fprintf(stderr,"fucking arguments\n"); return 1; }
 const char* input_path= argv[1];
 
 HMODULE libcygwin;
 conv_fun_t cygwin_conv_to_full_win32_path;
 libcygwin= LoadLibrary("cygwin1.dll");
 if (libcygwin==NULL) { fprintf(stderr,"fuck1\n"); return 1; }
 cygwin_conv_to_full_win32_path=
 (conv_fun_t)(GetProcAddress(libcygwin,"cygwin_conv_to_full_win32_path"));
 if (cygwin_conv_to_full_win32_path==NULL) { fprintf(stderr,"fuck2\n"); return 1; };
 
 char *windows_path= malloc(sizeof(char)*(MAX_PATH+1));
 fprintf(stderr,"calling cygwin-conv on '%s'\n", input_path);
 cygwin_conv_to_full_win32_path(input_path,windows_path);
 printf(windows_path);
 
 FreeLibrary(libcygwin);
 return 0;
 }
I compiled the program with
 gcc -mno-cygwin -g -o t t.c
Any ideas?
Thank's in advance & Best wishes
Sebastian
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