MinGWのmakeにパスを通すためのラッパー

make.cpp

#include <stdlib.h>
#include <unistd.h>
#include <string>
#include <vector>

#define MINGW "C:\\MinGW"
#define USR MINGW"\\msys\\1.0"

std::string lower(const std::string &s) {
	std::string ret;
	for (int i = 0; i < s.size(); i++) {
		char ch = s[i];
		if ('A' <= ch && ch <= 'Z') ch += 32;
		ret += ch;
	}
	return ret;
}

int main(int argc, const char *argv[], const char *envp[]) {
	const char *make = USR"\\bin\\make.exe";
	argv[0] = make;
	std::vector<const char *> envs;
	std::string path;
	for (int i = 0; envp[i]; i++) {
		std::string e = envp[i];
		std::string e5 = lower(e.substr(0, 5));
		if (e5 == "path=") {
			path = "PATH="USR"\\local\\bin;"USR"\\bin;"MINGW"\\bin;" + e.substr(5);
			envs.push_back(path.c_str());
		} else if (e5 != "lang=") {
			envs.push_back(envp[i]);
		}
	}
	envs.push_back("LANG=C");
	envs.push_back(NULL);
	return execve(make, argv, &envs[0]);
}