#include <stdio.h>
#include <io.h>
#include <sgtty.h>
#include <ctype.h>

#define NUM_MSG 20
#define MSG_SIZ 20
#define TRUE 1
#define FALSE 0

char msgarray[NUM_MSG][MSG_SIZ];	/* local array of args to pass on */
int pipeflag;		/* local flag for pipe_set and pipe_exec: TRUE == piping */
char pipein[] = "pipe.in";
char pipeout[] = "pipe.out";

/*
	Version 1.1		12 Nov 1989		Bob Presswood
*/


pipe_set(argc,argv)
int *argc; char *argv[];
{
/* Structures channel and fcbtab are defined in io.h */
	struct channel *chanptr;
	struct fcbtab *fcbptr;
	char drive[2], name[9], type[4], user[3];
	char *p, *t;
	int i, j, n;

	pipeflag = FALSE;
	for (i = 1; i < *argc; i++){
		/* If pipein exists in arg list, redirect stdin. */
		if (!strcmp(argv[i],pipein)){
			freopen(pipein,"r",stdin);
			for (j = i; j < (*argc - 1); j++)
				argv[j] = argv[j+1];
			(*argc)--;
			break;
		}
	}
	/* If < 2 args, there can't be a pipe. */
	if (*argc < 2){
		return();
	}
	for (i = 1; i < *argc; i++){
		if (!strcmp(argv[i],"|")){
			for (j = 0; j < NUM_MSG; j++)
				msgarray[j][0] = 0;				/* Null out msgarray */
			if ((p = index(argv[i+1],':')) && !index(argv[i+1],'/') && (p > (argv[i+1] + 1))){
				drive[0] = *argv[i+1];
				drive[1] = user[0] = user[1] = user[2] = '\0';
				for (j = 1; j < 3; j++){
					t = argv[i+1] + j;
					if (isdigit(*t))
						user[j-1] = *t;
				}
				strcpy(msgarray[0],user);
				strcat(msgarray[0],"/");
				strcat(msgarray[0],drive);
				strcat(msgarray[0],p);
			} else
				strcpy(msgarray[0], argv[i+1]);		/* Prog to run next */
			strcpy(msgarray[1], "?");				/* not passed by execv */
			strcpy(msgarray[2], pipein);			/* stdin from pipein */
			for (j = i + 2, n = 3; j < *argc; j++, n++)
				strcpy(msgarray[n], argv[j]);	/* Any other args */

			/* Is stdout redirected to a file? */
			if (!isatty(1)){
				drive[1] = name[8] = type[3] = user[2] = '\0';

				/* chantab from io.h, 1 is stdout */
				chanptr = &chantab[1];

				/* c_arg of chantab[1] is a pointer to stdout fcbtab */
				fcbptr = chanptr->c_arg;

				/* recover file, etc. for later stdout redirection */
				if (fcbptr->fcb.f_driv)
					drive[0] = fcbptr->fcb.f_driv + '@';
				else
					drive[0] = '\0';
				user[0] = (fcbptr->user > 9 ? '1' : '0');
				user[1] = (fcbptr->user > 9 ? fcbptr->user - 10 + '0' : fcbptr->user + '0');
				strncpy(name,fcbptr->fcb.f_name,8);
				if (p = index(name,' '))
					*p = '\0';
				strncpy(type,fcbptr->fcb.f_type,3);

				/* add redirected stdout file to msgarray */
				if (fcbptr->fcb.f_driv)
					sprintf(msgarray[n],"^%s/%s:%s.%s",user,drive,name,type);
				else
					sprintf(msgarray[n],"^%s/%s.%s",user,name,type);
			}
			freopen(pipeout,"w",stdout);
			*argc = i;		/* Extra args not needed for this prog. */
			pipeflag = TRUE;
			break;
		} else if (*argv[i] == '^'){
		/* '^' used to flag for output redirection at end of piping */
			freopen(argv[i]+1,"w",stdout);
			(*argc)--;
			break;
		}
	}
}


#define NUMPATH 5

char path[NUMPATH][6] = {
	"00/A:",
	"00/B:",
	"00/C:",
	"00/D:",
	"00/E:"
};

pipe_exec()
{
	char *msgv[NUM_MSG-1];
	char user, current[6], *p, fname[13];
	int i;

	/* Erase pipein, ignoring error if it does not exist. */
	unlink(pipein);
	if (pipeflag == TRUE){
		/* Close stdin and stdout, whether redirected or not. */
		fclose(stdin);
		fclose(stdout);

		/* If pipeout was created, it must be changed to pipein now. */
		rename(pipeout,pipein);

		/* Set array of pointers to char. */
		for (i = 0; i < NUM_MSG - 1; i++)
			if (strlen(msgarray[i+1]))
				msgv[i] = &msgarray[i+1];
			else
				msgv[i] = NULL;

		/* Chain and pass args. */
		execv(msgarray[0],msgv);
		strcpy(current,"  / :");
		user = bdos(0x20,0xff);
		current[3] = bdos(0x19,0) + 'A' ;
		current[0] = (user > 9 ? '1' : '0');
		current[1] = (user > 9 ? user - 10 + '0' : user + '0');
		if (p = index(msgarray[0],':'))
			strcpy(fname,p+1);
		else if (p = index(msgarray[0],'/'))
			strcpy(fname,p+1);
		else
			strcpy(fname,msgarray[0]);
		for (i = 0; i < NUMPATH; i++){
			if (strcmp(current,path[i])){
				strcpy(msgarray[0],path[i]);
				strcat(msgarray[0],fname);
				execv(msgarray[0],msgv);
			}
		}
		fprintf(stderr,"\nFile %s not found for piping.\n", fname);
		exit(1);
	}
}