usr/klibc/exec_l.c

/*
 * exec_l.c
 *
 * Common implementation of execl() execle() execlp()
 */

#include <stdarg.h>
#include <alloca.h>
#include <unistd.h>

int NAME(const char *path, const char *arg0, ...)
{
	va_list ap, cap;
	int argc = 1, rv;
	const char **argv, **argp;
	const char *arg;
	char *const *envp;

	va_start(ap, arg0);
	va_copy(cap, ap);

	/* Count the number of arguments */
	do {
		arg = va_arg(cap, const char *);
		argc++;
	} while (arg);

	va_end(cap);

	/* Allocate memory for the pointer array */
	argp = argv = alloca(argc * sizeof(const char *));
	if (!argv) {
		va_end(ap);
		return -1;
	}

	/* Copy the list into an array */
	*argp++ = arg0;
	do {
		*argp++ = arg = va_arg(ap, const char *);
	} while (arg);

#if EXEC_E
	/* execle() takes one more argument for the environment pointer */
	envp = va_arg(ap, char *const *);
#else
	envp = environ;
#endif

#if EXEC_P
	rv = execvpe(path, (char * const *)argv, envp);
#else
	rv = execve(path, (char * const *)argv, envp);
#endif

	va_end(ap);

	return rv;
}