/* ginaccint.cpp, a launcher that sets variables to start ginaccint.bin.
 * This is necessary because Cint is not libtoolized and so may need to have 
 * LD_LIBRARY_PATH and CINTSYSDIR set.  This cannot be done by a shell-script
 * because the #!-mechanism works only once and we want to enable the user to
 * write scripts using that mechanism. */

#include <unistd.h>
#include <stdlib.h>
#include <string>
#include <iostream>
#include "launch.h"

extern char **environ;

int main(int argc, char * *argv)
{
	// manually "expand" autoconf-style variables
	if (exec_prefix=="${prefix}")
		exec_prefix = prefix;
	if (bindir=="${exec_prefix}/bin")
		bindir = exec_prefix + "/bin";
	if (libdir=="${exec_prefix}/lib")
		libdir = exec_prefix + "/lib";
	// now we can guess what to start
	std::string binprog = bindir + "/ginaccint.bin";
	
	// extend LD_LIBRARY_PATH by libdir, so ginaccint.bin really finds libginac
	const char * LD_LIBRARY_PATH = getenv("LD_LIBRARY_PATH");
	if (LD_LIBRARY_PATH == NULL)
		setenv("LD_LIBRARY_PATH", libdir.c_str(), 1);
	else
		setenv("LD_LIBRARY_PATH", (std::string(LD_LIBRARY_PATH)+':'+libdir).c_str(), 1);
	
	// hard-wire CINTSYSDIR, inherited from configure, but only if it has
	// been set therein (to allow for system-wide installations of cint)
	// and without overriding it if the user has specified it.
	if (CINTSYSDIR != "@CINTSYSDIR@")
		setenv("CINTSYSDIR", CINTSYSDIR.c_str(), 0);
	
	// execute the real thing
	int error = execve(binprog.c_str(), argv, environ);
	
	// only gets here on error
	std::cerr << argv[0] << ": cannot exec " << binprog << std::endl;
	return error;
}