/* TECO for DOS  Copyright (C) 1986-1991 Matt Fichtenbaum					*/
/* Based on Ultrix TECO (C) 1986-1990 GenRad Inc., Concord, MA 01742		*/
/* These programs may be copied if this copyright notice is included and	*/
/* only on a "not for sale or profit" basis									*/

/* te_main.c  main program  12/08/90  20.15 */
/* 8-bit version  08/27/91  22.46		*/
/* improve dly_freebuff  01/12/92  14.25 */
/* add change directory command  03/30/92  20.44 */
/* current version  10/31/92  19.51 */
/* four buffers  03/10/93  22.16 */

/*
* This is TECO for DOS on a PC.  It is mostly compatible with DEC TECO
* as explained in the DEC TECO manual.  It was written from a manual for
* TECO-11 version 34, and so adheres most closely to that version.
*
* This program consists of several source files, as follows:
*
* teco.c (this file)		Main program - initialize, read command line and
*							startup file, handle errors, high-level read and
*							execute command strings.
*
* te_defs.h					Definitions file, to be #included with other files
*
*
* te_graph.h				Definitions file specific to display routines; an
*							artifact of substituting the routines in te_displ.c
*							for the corresponding Microsoft C library routines.
*
* keyscans.h				Definitions of the character codes used internally to
*							represent keyboard function, cursor, etc. keys.
*
* te_data.c					Global variables
*
* te_rdcmd.c				Read in a command string
*
* te_exec0.c				First-level command execution - numbers, values,
*							assemble expressions
*
* te_exec1.c				Most commands
*
* te_exec2.c				"E" and "F" commands, and file I/O
*
* te_srch.c					routines associated with "search" commands
*
* te_subs.c					higher-level subroutines
*
* te_utils.c				lower-level subroutines
*
* te_chari.c				keyboard (stdin), typeout (stdout), suspend
*
* te_mouse.c				mouse interface routines
*
* te_vga.c					vga display window and display special functions
*
* te_displ.c				focused implementation of Microsoft display library routines
*
* These routines should be compiled and linked to form the TECO executable.
*/
#include "te_defs.h"

static void cleanup(void), print_string(short);
static void save_args(int argc, char *argv[], struct qh *q);
static void read_startup(void);
void free_mem(void), set_term_par(void);
short read_cmdstr(void);

void main(int argc, char *argv[])
{
	short i;

	save_args(argc, argv, &qreg[36]);	/* copy command line to Qz */
	init_wd(1);							/* get name of current directory */
	qreg[1].f = (BUFFPTR) &id_cell;
	qreg[1].z = 62;
	read_startup();			/* read startup file */
	setup_tty(TTY_ON);		/* set tty to CBREAK, no echo, asynch mode */
	set_term_par();			/* set terminal screen-size parameters */
	window(WIN_INIT);		/* initialize screen-image buffer */
	qsp = &qstack[-1];		/* initialize q-reg stack pointer */

/* set up error restart */
	if (err = setjmp(xxx))
	{
		out_str("\r\n? ");
		out_str(errors[err-1]);
		if (err == E_EFI) goto quit;		/* EOF from standard input - clean up and exit */
		if (err == E_SRH) print_string(SERBUF);			/* print unfulfilled search string */
		else if ((err == E_FNF) || (err == E_COF) || (err == E_AMB)) print_string(filbuf);	/* or file string */
		else if (err == E_DIR) print_string(DIRNAME);	/* or directory string */
		crlf();
		eisw = 0;				/* stop indirect command execution */
		et_val &= ~(ET_CTRLC | ET_NOWAIT | ET_CTRLO | ET_NOECHO);	/* reset ^C trap, read w/o wait, ^O (unused), no echo */
		if (et_val & ET_QUIT)	/* if ET has "quit on error" set, exit (phone home) */
		{
			cleanup();			/* reset screen, keyboard, output files */
			exit(1);			/* and exit */
		}
	}

/* forever: read and execute command strings */

	for (exitflag = 1; exitflag >= 0; )		/* "exit" sets exitflag to -1; ^C to -2; "hangup" to -3 */
	{
		window(WIN_REFR);				/* display the buffer */
		free_blist(insert_p);			/* free any storage from failed insert */
		free_blist(dly_freebuff);		/* return any delayed cells and reset q-reg "use" counts */
		reset_q_usecounts();			/* reset q-reg use counts to "1" if error occurred */
		insert_p = dly_freebuff = NULL;
		et_val &= ~ET_QUIT;				/* clear "abort on error" */
		if (read_cmdstr()) goto quit;
		exitflag = 0;					/* enable ^C detector */
		if (!WN_scroll) window(WIN_REDRAW);		/* if not in scroll mode, force full redraw on first ^W or nW */
		exec_cmdstr();
	}

	if (exitflag == -2) ERROR(E_XAB);		/* ^C detected during execution */
/* exit from program */

  quit:
	ev_val = es_val = 0;	/* no last one-line window */
	window(WIN_REFR);		/* last display */
	cleanup();				/* reset screen, terminal, output files */
	free_mem();				/* return allocated memory */
	exit(0);				/* and quit */
}


/* reset screen state, keyboard state; remove open output files */

static void cleanup()
{
	short i;

	out_flush();
	window(WIN_OFF);			/* restore screen */
	setup_tty(TTY_OFF);			/* restore terminal */
	for (i = 0; i < MAX_BUFFERS; i++)	/* kill any open output files */
		kill_output(&out_files[i]);
	(void)set_wd(1);			/* reset original drive and directory */
}


/* print string for error message */
/* argument is subscript of a qreg qh, prints text from that buffer */

static void print_string(short arg)
{
	short i, c;
	BUFFPTR p;
	unsigned char tc;
	void out_char(unsigned char), out_stderr(unsigned char);
	void (*print_ptr)(unsigned char) = (et_val & ET_GRAPH) ? out_stderr : out_char;
	(*print_ptr)('"');
	for (p = qreg[arg].f, c = 0, i = 0; i < qreg[arg].z; i++)
	{
		if (!(tc = p->ch[c])) break;
		if (tc < 040)		/* ctrl char */
			switch (tc)
			{
				case CR:
				case LF:	(*print_ptr)(tc);						break;
				case TAB:	(*print_ptr)(' ');	(*print_ptr)(' ');	break;
				case ESC:	(*print_ptr)('$');						break;
				default:	(*print_ptr)('^');	(*print_ptr)((char)(tc | 0100));	break;
			}
		else (*print_ptr)(tc);
		if (++c > CELLSIZE-1)
		{
			p = p->f;
			c = 0;
		}
	}
	(*print_ptr)('"');
}

void out_stderr(unsigned char c)
{
	putc((int) c, stderr);
}
/* copy invocation command line to a text buffer */

static void save_args(int argc, char *argv[], struct qh *q)
{
	unsigned char c;
	struct qp ptr;

	make_buffer(q);				/* attach a text buffer */
	ptr.p = q->f;				/* initialize pointer to output string */
	ptr.c = q->z = 0;			/* and output char count */
	for (; argc > 0; argv++, argc--)	/* for each arg */
	{
		while ( ((c = *((*argv)++)) != '\0') && (q->z < CELLSIZE-1) )
		{
			ptr.p->ch[ptr.c] = c;		/* copy char to q-reg */
			fwdcx(&ptr);
			++q->z;						/* count characters */
		}
		if (argc > 1)					/* if not last argument... */
		{
			ptr.p->ch[ptr.c] = ' ';		/* space to separate arguments */
			fwdcx(&ptr);
			++q->z;
		}
	}
}



/* routine to read startup file */

static unsigned char startup_name[] = "teco.ini";		/* name of startup file */

static void read_startup()
{
	unsigned char *p_init, *p_temp;
	char *getenv();
	unsigned char temp_name[80];

/* look for "teco.ini" in current directory first */
/* if not found, use environment variable "teco" as path */

	if (!(eisw = fopen(&startup_name[0], "r")))
	{
		if ((p_init = getenv("TECO")) != 0)
		{
			for (p_temp = temp_name; *p_init != 0; )	/* copy path */
				*p_temp++ = *p_init++;
			*p_temp++ = '\\';			/* separator */
			for (p_init = startup_name; *p_init != 0; )	/* copy filename */
				*p_temp++ = *p_init++;
			*p_temp = '\0';
			eisw = fopen(temp_name, "r");		/* set eisw if file found */
		}
	}
}