system.c

#include <errno.h>
#include <signal.h>
#include <limits.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <windows.h>

#define	SHELL_PATH	L"/Windows/command.exe"	/* Path of the shell.  */
#define SHELL_OPTION	L"/c "

//#define SHELL_PATH L"/usr/bin/ash.exe"
//#define SHELL_PATH L"/usr/bin/ash"
//#define SHELL_PATH L"/usr/bin/ush"
//#define SHELL_PATH L"/bin/ush"
//#define SHELL_PATH L"/bin/sh"
//#define SHELL_OPTION L"-c "

/* Execute LINE as a shell command, returning its status.  */
static int do_system(const char *line) {
	unsigned long int result;
	PROCESS_INFORMATION pi;

	//wchar_t wline[PATH_MAX];
	//mbstowcs(wline, line, PATH_MAX);

	wchar_t command_line[PATH_MAX] = SHELL_OPTION;
	//wcscat(args, wline);
	mbstowcs(command_line + (sizeof SHELL_OPTION / sizeof(wchar_t) - 1), line, PATH_MAX);

	if(!CreateProcessW(SHELL_PATH, command_line, NULL, NULL, 0, 0, NULL, NULL, NULL, &pi)) return 127;
	WaitForSingleObject(pi.hProcess, INFINITE);
	GetExitCodeProcess(pi.hProcess, &result);
	CloseHandle(pi.hProcess);
	CloseHandle(pi.hThread);
	return result;
}

int system(const char *line) {
	if(!line) return do_system("exit") == 0;
	return do_system(line);
}