I am using LD_PRELOAD to hook a library function, and in Linux it works perfectly. But I cannot figure out how to do the equivalent in OSX.
The setup I have on Linux is as follows:
The code is:
#include <stdio.h>
#include <dlfcn.h>
#include <stdlib.h>
#include <unistd.h>
#include <ruby.h>
void
rb_raise(unsigned long exc, const char *fmt, ...)
{
static void (*libruby_rb_raise)
(unsigned long exc, const char *fmt, ...) = NULL;
void * handle;
char * error;
if (!libruby_rb_raise) {
handle = dlopen("/path/to/libruby.so",
RTLD_LAZY);
if (!handle) {
fputs(dlerror(), stderr);
exit(1);
}
libruby_rb_raise = dlsym(handle, "rb_raise");
if ((error = dlerror()) != NULL) {
fprintf(stderr, "%s\n", error);
exit(1);
}
}
// ...code...
return Qnil;
}
Which I then compile with:
gcc -Wall -O2 -fpic -shared -ldl -g -I/path/to/includes/ -o raise_shim.so raise_shim.c
I then execute with:
LD_PRELOAD=./raise_shim.so ruby
All of the above works well on Linux, what is the equivalent for each step to get this working on OSX? I have googled this and have not been able to get it to work with the information provided as the info for some of the steps are missing.
Thanks in advance!