/*
   89/03/02: ERS: added the "mode" argument for MS-DOS/Unix
   compatibility. Added prototypes for GNU C.

   fixed spawnve: the original didn't pass the command tail
   correctly, nor did it handle errno right. Also, this version
   passes args in the environment as well as the command line,
   using the ARGV= mechanism supported by crt0.s

   Written 89/01/10 by ERS. Original version Copyright (c) 1988 by
   Memorial University of Newfoundland. This version is based upon
   that original, but is substantially different. (In fact, there
   probably isn't a single line of the original left.)

   Adapted 90/06/25 by ERS to MiNT.
*/

#include	<stdarg.h>
#include	<process.h>
#include	<param.h>
#include	<errno.h>
#include	<osbind.h>
#include	<mintbind.h>
#include	<stdlib.h>
#include	<time.h>
#include	<string.h>
#include	"lib.h"

#define TOS_ARGS 126

extern char **environ;
extern int __mint;

static	char	cmd[TOS_ARGS+1];

int
_spawnve(mode, _path, argv, envp)
	int	mode;
	char	*_path;
	char	**argv;
	char	**envp;
{
	extern void _exit();
	static char	path[MAXPATHLEN];
	int		cmlen = 0;
	int		enlen = 0;
	char		*p;
	char		*s, *t;
	char		*env;
	long		rval;

	if (mode != P_WAIT && mode != P_OVERLAY && mode != P_NOWAIT) {
		errno = EINVAL;
		return -1;
	}
	(void)_unx2dos(_path, path);	/* convert filename, if necessary */
	if (!envp)
		envp = environ;

/* count up space needed for environment */
	for(cmlen = 0; argv[cmlen]; cmlen++)
		enlen += strlen(argv[cmlen]) + 1;
	for(cmlen = 0; envp[cmlen]; cmlen++)
		enlen += strlen(envp[cmlen]) + 1;
	enlen += 32;	/* filler for stuff like ARGV= and zeros */

	if (!(env = (char *)Malloc((long)enlen))) {
		errno = ENOMEM;
		return -1;
	}
	s = env;
	while ((p = *envp) != 0) {
/*
 * NOTE: in main.c, we converted the PATH environment variable into
 * POSIX form. Here, we convert back into gulam form. Note that the
 * new variable will be shorter than the old, so space is not a problem.
 */
		if (!strncmp(p, "PATH=", 5)) {
			strncpy(s, p, 5); s += 5; p += 5;
			while (*p) {
				if (!strncmp(p, "/dev/", 5) && p[5]) {
					*s++ = p[5];
					*s++ = ':';
					p += 6;
				} else if (*p == ':') {
					*s++ = ','; p++;
				} else if (*p == '/') {
					*s++ = '\\'; p++;
				} else {
					*s++ = *p++;
				}
			}
		} else {
			while(*p)
				*s++ = *p++;
		}
		*s++ = '\0';
		envp++;
	}
	
	strcpy(s, "ARGV=");
	s += 6; /* s+=sizeof("ARGV=") */

/* copy argv[0] first (because it doesn't go into the command line */
	if (argv && *argv) {
		for (p = *argv; *p; )
			*s++ = *p++;
		*s++ = '\0';
	}

	bzero(t = cmd, sizeof(cmd));

/* s points at the environment's copy of the args */
/* t points at the command line copy to be put in the basepage */

	if (argv && *argv) {
		t++;
		while (*++argv) {
			p = *argv;
			while (*p) {
                              if (cmlen <= TOS_ARGS) {
                                      *t++ = *p; cmlen++;
                              }
				*s++ = *p++;
			}
                        if (cmlen <= TOS_ARGS && *(argv+1)) {
                                *t++ = ' '; cmlen++;
                        }
			*s++ = '\0';
		}
/*                *cmd = (char) cmlen;  NOT ANY MORE */
	}

	/* tie off environment */
	*s++ = '\0';
	*s = '\0';

	/* signal Extended Argument Passing */
	*cmd = 0x7f;

/* MiNT and MicroRTX support background processes with Pexec(100,...) */
/* MiNT supports overlays with Pexec(200,...) */

	if (mode == P_NOWAIT) cmlen = 100;
	else if (mode == P_OVERLAY && __mint) cmlen = 200;
	else cmlen = 0;

	rval = Pexec(cmlen, path, cmd, env);

	if (rval < 0)
	{
		errno = -rval;
		rval = -1;
	}
	else if (mode == P_OVERLAY)
	/* note that we get here only if MiNT is not active! */
		_exit((int)rval);
	(void)Mfree(env);
	return rval;
}