/* G U N I X I O  --  UNIX i/o module for gkermit */

/*
  UNIX i/o functions for gkermit.

  Author:
    Frank da Cruz
    Originally at:
      The Kermit Project
      Columbia University
      612 West 115th Street
      New York NY 10025-7799  USA
      http://www.columbia.edu/kermit/
      kermit@columbia.edu
    As of October 2011:
      The New Open-Source Kermit Project
      Bronx NY
      http://kermitproject.org
      kermit@kermitproject.org
    Last update: Mon Nov 15 09:48:53 2021
      Suppress warning about write(1,"\015\012",2); in ttres().

  Copyright (C) 1999, 2021
  The Trustees of Columbia University in the City of New York.
  Issued under the GNU General Public License as it existed in 1999.

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

/*
 CONTENTS...

 Console Output:
   tmsg   - Type a message
   tmsgl  - Type a line

 Communication Device:
   ttopen - Open
   ttpkt  - Put in packet mode
   ttres  - Restore normal mode
   ttinl  - Input a raw packet
   ttol   - Send a packet
   ttchk  - Check if input ready
   ttflui - Flush input buffer

 File:
   zchki  - See if file can be opened for input
   zopeni - Open input file
   zopeno - Open output file
   zclosi - Close input file
   zcloso - Close output file
   zrtol  - Remote-to-Local filename conversion
   zltor  - Local-to-Remote filename conversion
   zgetc  - Get character from input file
*/

#include <stdio.h>			/* Standard input/output */

#ifdef POSIX
#include <termios.h>			/* Terminal modes */
#else
#ifdef SYSV
#include <termio.h>
#else
#include <sgtty.h>
#endif /* SYSV */
#endif /* POSIX */

#include <ctype.h>			/* Character types */
#include <sys/types.h>			/* Needed e.g. by <stat.h> */
#include <signal.h>			/* Interrupts */
#include <setjmp.h>			/* Longjumps */
#include <sys/stat.h>			/* File exist, file size */
#include <errno.h>			/* Error symbols */
#include "gkermit.h"			/* gkermit definitions */

/* All versions of HP-UX need Xon/Xoff */

#ifdef hpux				/* HP-UX Pre-7.00 */
#ifndef __hpux
#define __hpux
#endif /* __hpux */
#endif /* hpux */

#ifdef __hpux				/* HP-UX 7.00 and later */
#ifndef SETXONXOFF
#define SETXONXOFF
#endif /* SETXONXOFF */
#endif /*  __hpux */

#ifdef NOXONXOFF			/* -DNOXONXOFF overrides */
#ifdef SETXONXOFF
#undef SETXONXOFF
#endif /* SETXONXOFF */
#endif /* NOXONXOFF */

#ifndef TINBUFSIZ			/* read() inpbut buffer */
#ifdef USE_GETCHAR
#define TINBUFSIZ 0			/* getchar() has its own */
#else
#ifdef SMALL
#define TINBUFSIZ 240
#else
#define TINBUFSIZ 4080
#endif /* SMALL */
#endif /* USE_GETCHAR */
#endif /* TINBUFSIZ */

#ifndef DUMBIO
#ifndef USE_GETCHAR
#ifndef NOFCNTL_H			/* For nonblocking buffered read() */
#ifdef SYS_FCNTL_H
#include <sys/fcntl.h>
#else
#include <fcntl.h>
#ifndef O_NDELAY
#ifdef O_NONBLOCK
#define O_NDELAY O_NONBLOCK
#endif /* O_NONBLOCK */
#endif /* O_NDELAY */
#endif /* SYS_FCNTL_H */
#endif /* NOFCNTL_H */
#endif /* USE_GETCHAR */
#endif /* DUMBIO */

#ifdef O_NDELAY				/* For System V R3 and earlier */
#ifndef EWOULDBLOCK
#ifdef EAGAIN
#define EWOULDBLOCK EAGAIN
#endif /* EAGAIN */
#endif /* EWOULDBLOCK */
#endif /* O_NDELAY */

#ifndef DUMBIO				/* To force single-char read/write */
#ifndef USE_GETCHAR
#ifndef O_NDELAY
#define DUMBIO
#endif /* O_NDELAY */
#endif /* USE_GETCHAR */
#endif /* DUMBIO */

/* Header file deficiencies section... */

#ifndef R_OK
#define R_OK 4
#endif /* R_OK */

#ifndef W_OK
#define W_OK 2
#endif /* W_OK */

#ifndef _IFMT
#ifdef S_IFMT
#define _IFMT S_IFMT
#else
#define _IFMT 0170000
#endif /* S_IFMT */
#endif /* _IFMT */

#ifndef S_ISREG
#define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
#endif /* S_ISREG */

/* External variables */

extern int literal;			/* Literal filenames */
extern int quiet;			/* No messages */
extern int keep;			/* Keep incomplete files */
extern int streamok;			/* OK to offer streaming */
extern int nomodes;			/* Don't get/set tty modes */
extern int xonxoff;			/* Set Xon/Xoff */
extern int noxonxoff;			/* Don't set Xon/Xoff */
extern FILE * db;			/* Debug log file */

/* Exported variables */

FILE *ifp, *ofp;			/* Input and output file pointers */
char zinbuf[MAXRECORD+1];		/* File input buffer */
int zincnt = 0;				/* count */
char * zinptr = NULL;			/* and pointer. */

/* Private global variables */

static int havemodes = 0;		/* Have obtained terminal modes */
static int ttflags = -1;		/* Terminal flags */
static int nonblock = 0;		/* Nonblocking i/o enabled */
static char tinbuf[TINBUFSIZ+16];	/* Communications input buffer */
static char * tinptr = NULL;		/* Pointer to current item */
static int tincnt = 0;			/* Buffer count */
static int tlast = 0;			/* Last item in buffer */
static int xparity = 0;			/* Parity in use, 0 = none */
static int raw = 0;			/* Terminal rawmode flag */
static char work[MAXPATHLEN+1];		/* Filename conversion buffer */

/* Terminal mode structs */

#ifdef POSIX				/* POSIX */
static struct termios ttold, ttraw;
#else
#ifdef SYSV				/* System V */
static struct termio ttold = {0};
static struct termio ttraw = {0};
#else
#ifdef BSD				/* 4.2 BSD or UNIX V7 */
static struct sgttyb ttold, ttraw;
#endif /* BSD */
#endif /* SYSV */
#endif /* POSIX */

static jmp_buf jbuf;			/* Longjump buffer for timeouts */

/* Functions... */

SIGTYP
doexit(x) int x; {			/* Exit routine */
    if (x)				/* If failure */
      ttflui();				/* flush pending junk we won't read */
    ttres();				/* Reset the communication device */
#ifdef F_SETFL
    if (ttflags > -1)			/* Restore its flags */
      fcntl(0,F_SETFL,ttflags);
#endif /* F_SETFL */
    if (debug) {
	fprintf(db,"exit %d\n",x);
	fclose(db);
    }
    exit(x);
}

VOID
sysinit() {				/* To be run first thing */
#ifdef F_SETFL
    ttflags = fcntl(0,F_GETFL,0);	/* Get and save stdin flags */
#endif /* F_SETFL */
#ifdef SIGINT
    signal(SIGINT,SIG_IGN);		/* Ignore interrupts */
#endif /* SIGINT */
#ifdef SIGTSTP
    signal(SIGTSTP,SIG_IGN);
#endif /* SIGTSTP */
#ifdef SIGQUIT
    signal(SIGQUIT,SIG_IGN);
#endif /* SIGQUIT */
    signal(SIGHUP,doexit);		/* Go here on hangup */
}

/* Console Functions */

#ifdef COMMENT				/* (not used) */
VOID
tmsg(s) char *s; {			/* tmsg() */
    if (!quiet)
      fprintf(stderr,"%s",s);		/* Type message on the screen. */
}
#endif /* COMMENT */

VOID
tmsgl(s) char *s; {			/* tmsgl() */
    if (!quiet) {
	if (raw)
	  fprintf(stderr,"%s\r\n",s);	/* Type message with CRLF */
	else
	  fprintf(stderr,"%s\n",s);
    }
}

/* Debugging functions */

VOID
logerr(s) char * s; {			/* Log text and errno */
    if (!s) s = "";
    if (!debug) return;
    if (db) fprintf(db,"%s: errno = %d\n",s,errno);
}

/* Parity function */

char
#ifdef __STDC__
dopar(char ch)
#else
dopar(ch) char ch;
#endif /* __STDC__ */
{					/* Do parity */
    unsigned int a;
    if (!xparity) return(ch); else ch &= 0177;
    switch (xparity) {
      case 'm':  return(ch | 128);	/* Mark */
      case 's':  return(ch & 127);	/* Space */
      case 'o':				/* Odd (fall thru) */
      case 'e':				/* Even */
	a = (ch & 15) ^ ((ch >> 4) & 15);
	a = (a & 3) ^ ((a >> 2) & 3);
	a = (a & 1) ^ ((a >> 1) & 1);
	if (xparity == 'o') a = 1 - a;	/* Switch sense for odd */
	return(ch | (a << 7));
      default: return(ch);
    }
}

/* Communication functions */

int
ttopen(ttname) char *ttname; {		/* "Open" the communication device */
    if (debug) {			/* Vital statistics for debug log */
#ifdef __STDC__
	fprintf(db,"ttopen __STDC__\n");
#endif /* __STDC__ */
#ifdef SIG_V
	fprintf(db,"ttopen SIG_V\n");
#else
#ifdef SIG_I
	fprintf(db,"ttopen SIG_I\n");
#endif /* SIG_I */
#endif /* SIG_V */
#ifdef USE_GETCHAR
	fprintf(db,"ttopen getchar/putchar\n");
#ifdef BUFSIZ
	fprintf(db,"ttopen BUFSIZ = %d\n", BUFSIZ);
#endif /* BUFSIZ */
#else
#ifdef DUMBIO
	fprintf(db,"ttopen single-byte read/write\n");
#else
	fprintf(db,"ttopen nonblocking read/write\n");
#endif /* DUMBIO */
#endif /* USE_GETCHAR */
	fprintf(db,"ttopen TINBUFSIZ = %d\n", TINBUFSIZ);
#ifdef __hpux
	fprintf(db,"ttopen __hpux\n");
#endif /* __hpux */
#ifdef pdp11
	fprintf(db,"ttopen pdp11\n");
#endif /* pdp11 */
#ifdef SETXONXOFF
	fprintf(db,"ttopen SETXONXOFF\n");
#endif /* SETXONXOFF */
	fprintf(db,"ttopen xonxoff = %d\n",xonxoff);
	fprintf(db,"ttopen noxonxoff = %d\n",noxonxoff);
	fprintf(db,"ttopen ttflags %d\n",ttflags);
	fprintf(db,"ttopen nomodes %d\n",nomodes);
    }
    if (nomodes) {			/* If external protocol */
#ifdef SIGINT				/* exit on interrupts */
	signal(SIGINT,doexit);
#endif /* SIGINT */
#ifdef SIGTSTP
	signal(SIGTSTP,doexit);
#endif /* SIGTSTP */
#ifdef SIGQUIT
	signal(SIGQUIT,doexit);
#endif /* SIGQUIT */
	return(0);
    }

#ifndef DUMBIO
#ifndef USE_GETCHAR
#ifdef O_NDELAY
#ifdef F_SETFL
    if (ttflags != -1) {		/* Set nonbocking i/o on stdin */
	errno = 0;
	if (fcntl(0, F_SETFL,ttflags|O_NDELAY) == -1)
	  logerr("ttopen fcntl(0,F_SETFL,O_NDELAY)");
	else
	  nonblock = 1;
    }
#endif /* F_SETFL */
#endif /* O_NDELAY */
#endif /* USE_GETCHAR */
#endif /* DUMBIO */
    if (!nonblock)			/* No streaming without */
      streamok = -1;			/* nonblocking reads */

    if (debug)
      fprintf(db,"ttopen nonblock = %d\n", nonblock);
#ifdef POSIX
    tcgetattr(0,&ttold);		/* Get stdin device attributes */
    tcgetattr(0,&ttraw);
#else
#ifdef SYSV
    ioctl(0,TCGETA,&ttold);
    ioctl(0,TCGETA,&ttraw);
#else
#ifdef BSD
    gtty(0,&ttold);
    gtty(0,&ttraw);
#endif /* BSD */
#endif /* SYSV */
#endif /* POSIX */
    havemodes++;
    return(0);
}

int
ttpkt(parity) int parity; {		/* Put comm device in packet mode */
#ifdef BSD
    int x;
#endif /* BSD */
    xparity = parity;			/* Make local copy of parity */
    if (nomodes)
      return(0);

#ifdef SVORPOSIX			/* System V or POSIX section... */
    ttraw.c_iflag |= IGNPAR;
    ttraw.c_lflag &= ~(ICANON|ECHO);
    ttraw.c_lflag &= ~ISIG;
    ttraw.c_lflag |= NOFLSH;
#ifdef SETXONXOFF
    if (!noxonxoff) {
	ttraw.c_iflag |= (IXON|IXOFF);
	if (debug) fprintf(db,"ttpkt SVORPOSIX Xon/Xoff\n");
    }
#else
    if (xonxoff) {
	if (debug) fprintf(db,"ttpkt SVORPOSIX Xon/Xoff\n");
	ttraw.c_iflag |= (IXON|IXOFF);
    }
#endif /* SETXONXOFF */
#ifdef IEXTEN
    ttraw.c_lflag &= ~IEXTEN;
#endif /* IEXTEN */
#ifdef POSIX
    ttraw.c_iflag &= ~(IGNBRK|INLCR|IGNCR|ICRNL|INPCK|ISTRIP);
#else
    ttraw.c_iflag &= ~(IGNBRK|INLCR|IGNCR|ICRNL|INPCK|ISTRIP|IXANY);
#endif /* POSIX */
    ttraw.c_oflag &= ~OPOST;
    ttraw.c_cflag &= ~(CSIZE);
    ttraw.c_cflag |= (CS8|CREAD|HUPCL);
    ttraw.c_cflag &= ~(PARENB);

#ifndef VEOF
    ttraw.c_cc[4] = 1;
#else
#ifdef VMIN
    ttraw.c_cc[VMIN] = 1;
#endif /* VMIN */
#endif /* VEOF */

#ifndef VEOL
    ttraw.c_cc[5] = 0;
#else
#ifdef VTIME
    ttraw.c_cc[VTIME] = 0;
#endif /* VTIME */
#endif /* VEOL */

#ifdef VINTR
    ttraw.c_cc[VINTR] = 0;
#endif /* VINTR */

#ifdef POSIX
    if (tcsetattr(0,TCSADRAIN,&ttraw) < 0)
      return(-1);
#else
    if (ioctl(0,TCSETAW,&ttraw) < 0)
      return(-1);
#ifdef SYSV
#endif /* SYSV */
#endif /* POSIX */

#else  /* Not SVORPOSIX */

#ifdef BSD
    ttraw.sg_flags |= RAW;		/* BSD/V7 raw (binary) mode */
#ifdef SETXONXOFF
    if (!noxonxoff) {
	ttraw.sg_flags |= TANDEM;
	if (debug) fprintf(db,"ttpkt BSD Xon/Xoff\n");
    }
#else
    if (xonxoff) {
	ttraw.sg_flags |= TANDEM;
	if (debug) fprintf(db,"ttpkt BSD Xon/Xoff\n");
    }
#endif /* SETXONXOFF */
    ttraw.sg_flags &= ~(ECHO|CRMOD);    /* No echo, etc */
    if (stty(0,&ttraw) < 0) return(-1); /* Set modes */
#else
    system("stty raw -echo");
#endif /* BSD */
#endif /* SVORPOSIX */
    raw = 1;				/* Flag we're now in raw mode */
    return(0);
}

int
ttres() {				/* Reset terminal */
    int dummy = 0;                      /* Suppress warning about write() */
    int x = 0;                          /* API return codes */
    if (havemodes) {			/* Restore old modes */
#ifdef POSIX
	x = tcsetattr(0,TCSADRAIN,&ttold);
#else
#ifdef SYSV
	sleep(1);			/* Let output finish */
	x = ioctl(0,TCSETAW,&ttold);
#else
#ifdef BSD
	sleep(1);			/* Let output finish */
	x = stty(0,&ttold);
#else
	x = system("stty -raw echo");
#endif /* BSD */
#endif /* SYSV */
#endif /* POSIX */
    }
    dummy = (int) write(1,"\015\012",2);
    raw = 0;
    return(x);
}

int
ttchk() {				/* Check if input ready */
    int x = 0;
    if (nonblock) {			/* Try to read */
	errno = 0;
	x = read(0,&tinbuf[tlast],TINBUFSIZ-tlast);
#ifdef EXTRADEBUG
	fprintf(db,"ttchk read %d errno = %d\n",x,errno);
#endif /* EXTRADEBUG */
#ifdef EWOULDBLOCK
	if (x < 0 && errno == EWOULDBLOCK) /* Nothing to read */
	  x = 0;
#endif /* EWOULDBLOCK */
	if (x < 0)			/* Fatal i/o error */
	  return(-1);
    }
    tincnt += x;			/* Buffer bookkeeping */
    tlast  += x;
    return(x + tincnt);			/* How much is waiting to be read */
}

int
ttflui() {				/* Flush comm device input buffer */
#ifdef BSD
    long n = 1;				/* Specify read queue */
#endif /* BSD */
    int x;
    tincnt = 0;				/* Our own buffer */
    tlast = 0;
    tinptr = tinbuf;
    errno = 0;
#ifdef POSIX
    x = tcflush(0,TCIFLUSH);		/* kernel/driver buffers */
#else
#ifdef SYSV
    x = ioctl(0,TCFLSH,0);
#else
#ifdef BSD
    x = ioctl(0,TIOCFLUSH,&n);
#endif /* BSD */
#endif /* SYSV */
#endif /* POSIX */
    if (debug) fprintf(db,"ttflui = %d, errno = %d\n",x,errno);
    return(x);
}

SIGTYP
timerh(dummy) int dummy; {		/* Timeout handler */
    longjmp(jbuf,1);
    SIGRETURN;
}

/*
 ttinl() - Read a raw packet.

 Call with:
   dest - where to put it
   max  - maximum length
   timo - timeout (seconds, 0 = none)
   eol  - packet terminator
   turn - half-duplex line turnaround character to wait for, 0 = none

 Returns length obtained, or -1 if error or timeout, -2 on disconnection.
*/
#ifndef DEBUGWRAP
#define DEBUGWRAP 48
#endif /* DEBUGWRAP */

int
#ifdef __STDC__
ttinl(char * dest, int max, int timo, char eol, char soh, int turn)
#else
ttinl(dest,max,timo,eol,soh,turn) int max, timo, turn; char eol, soh, *dest;
#endif /* __STDC__ */
{
    int n = 0, x = 0, flag = 0, rc = 0, ccn = 0; /* Local variables */
    char c = NUL;
    int havelen = 0, pktlen = 0, lplen = 0;

#ifdef USE_GETCHAR
    if (debug) fprintf(db,"ttinl getchar timo = %d\n",timo);
#else
    if (debug) fprintf(db,"ttinl read timo = %d\n",timo);
#endif /* USE_GETCHAR */
    *dest = NUL;			/* Clear destination buffer */
    if (timo) {
	signal(SIGALRM,timerh);		/* Enable timer interrupt */
	alarm(timo);			/* Set it. */
    }
    if (setjmp(jbuf)) {			/* Timer went off? */
	if (debug) fprintf(db,"ttinl timeout\n");
        rc = -1;			/* Yes, set this return code. */
    } else {				/* Otherwise... */
	while (1) {			/* Read until we have a packet */
#ifdef DUMBIO
	    x = read(0,&c,1);		/* Dumb blocking read byte loop */
	    if (x < 0) {
		logerr("ttinl XX read 1");
		rc = -2;
	    }
#else
#ifdef USE_GETCHAR
	    errno = 0;
	    x = getchar();		/* Buffered read with getchar() */
	    if (x == EOF) {
		if (errno == EINTR)
		  continue;
		logerr("ttinl getchar");
		rc = -2;
	    }
	    c = x;
#else  /* USE_GETCHAR */
#ifdef O_NDELAY
	    if (nonblock) {		/* Buffered nonblocking read() */
		int x;
		if (tincnt < 1) {	/* Need to fill our buffer */
		    errno = 0;
		    tincnt = read(0,tinbuf,TINBUFSIZ);
		    if (tincnt > -1) tlast = tincnt;
		    if (debug)
		      fprintf(db,"ttinl nonblock tincnt=%d errno=%d\n",
			      tincnt,errno);
		    if (tincnt == 0 || errno == EWOULDBLOCK) {
#ifdef F_SETFL
			/* Go back to blocking and wait for 1 char */
			if (ttflags != -1) {
			    errno = 0;
			    x = fcntl(0, F_SETFL, ttflags  & ~O_NDELAY);
			    if (x == -1 || errno)
			      logerr("ttinl fcntl O_NDELAY off");
			    errno = 0;
			    tincnt = read(0,tinbuf,1);
			    if (tincnt < 1 || errno)
			      logerr("ttinl BL read");
			    errno = 0;
			    fcntl(0, F_SETFL, ttflags | O_NDELAY);
			    if (x == -1 || errno)
			      logerr("ttinl fcntl O_NDELAY on");
			}
			if (tincnt == 0) { /* Check results */
			    continue;
			}
			if (tincnt < 0) { /* I/O error */
			    rc = -2;
			    goto xttinl;
			}
			if (debug)
			  fprintf(db,"ttinl blocking read %d\n",tincnt);
#else
			/* No other form of sleeping is portable */
			sleep(1);
			continue;
#endif /* F_SETFL */
		    } else if (tincnt < 0) {
			rc = -2;
			goto xttinl;
		    }
		    tinptr = tinbuf;
		}
		c = *tinptr++;
		tincnt--;
	    } else {
#endif /* O_NDELAY */
		x = read(0,&c,1);	/* Dumb read byte loop */
		if (x < 0) {
		    logerr("ttinl XX read 1");
		    rc = -2;
		}
#ifdef O_NDELAY
	    }
#endif /* O_NDELAY */
#endif /* USE_GETCHAR */
#endif /* DUMBIO */
	    if (rc < 0)
	      break;
	    if (xparity)		/* Strip parity */
	      c &= 0x7f;
#ifdef COMMENT
	    /* Only uncomment in emergencies */
	    if (debug)
	      fprintf(db,"ttinl char=%c flag=%d tincnt=%d\n",c,flag,tincnt);
#endif /* COMMENT */
	    if (c == '\03') {		/* Got ^C, count it. */
	    	if (++ccn > 2) {	/* If more than 2, let them out */
		    fprintf(stderr,"^C...");
		    ttres();
		    if (debug) fprintf(db,"ttinl interrupted\n");
		    dest[n = 0] = NUL;
		    rc = -9;
		    goto xttinl;
		}
	    } else			/* Not ^C so reset counter*/
	      ccn = 0;

	    if (!flag && (c != soh))	/* Look for SOH */
	      continue;			/* Skip stuff between packets */
	    flag = 1;			/* Have SOH */

	    if (n >= max) {
		if (debug) fprintf(db,"ttinl overflow\n");
		rc = -2;
		goto xttinl;
	    }
	    dest[n++] = c;		/* Store the character */
#ifdef USE_EOL
	    /* Use EOL to determine end of packet */
	    if (c == eol) {
		dest[n] = NUL;
		break;
	    }
#else
	    /* Use length field for framing */
	    if (!havelen) {
		if (n == 2) {
		    pktlen = xunchar(dest[1] & 0x7f);
		    if (pktlen > 1) {
			if (debug) fprintf(db,"ttinl length = %d\n",pktlen);
			havelen = 1;
		    }
		} else if (n == 5 && pktlen == 0) {
		    lplen = xunchar(dest[4] & 0x7f);
		} else if (n == 6 && pktlen == 0) {
		    pktlen = lplen * 95 + xunchar(dest[5] & 0x7f) + 5;
		    if (debug) fprintf(db,"ttinl length = %d\n",pktlen);
		    havelen = 1;
		}
	    }
	    if (havelen && (n > pktlen+1)) {
		if (turn && c != turn)	/* Wait for turnaround char */
		  continue;
		dest[n] = NUL;		/* Null-terminate whatever we got */
		break;
	    }
#endif /* USE_EOL */
	}
    }
  xttinl:				/* Common exit point */
    if (timo) {
	alarm(0);			/* Turn off the alarm */
	signal(SIGALRM,SIG_IGN);	/* and associated interrupt */
    }
    if (debug && n > 0) {		/* Log packet */
#ifndef FULLPACKETS
	if (n > DEBUGWRAP) {		/* Truncate if it would wrap */
	    dest[n] = NUL;		/* in case of interruption */
	    c = dest[DEBUGWRAP];
	    dest[DEBUGWRAP] = NUL;
	    fprintf(db,"PKT<-[^A%s...](%d) rc=%d\n",&dest[1],n,rc);
	    dest[DEBUGWRAP] = c;

	} else
#endif /* FULLPACKETS */
	    fprintf(db,"PKT<-[^A%s](%d) rc=%d\n",&dest[1],n,rc);
    }
    if (rc == -9)			/* Interrupted by user */
      doexit(1);
    else if (rc > -1)
      rc = n;
    return(rc);				/* Return length, or failure. */
}

int
ttol(s,len) int len; char *s; {		/* Output string s of given length  */
    register int i = 0, n = 0, m = 0;
    int partial = 0;

    n = len;
    if (n < 0) {
	if (debug) fprintf(db,"ttol len = %d\n",n);
	return(-1);
    }
    if (xparity) {			/* Add parity if requested */
	for (i = 0; i < n; i++)
	  s[i] = dopar(s[i]);
    }
    if (debug) {			/* Log the packet if requested */
	char c;
#ifndef FULLPACKETS
	if (n > DEBUGWRAP) {
	    c = s[DEBUGWRAP];
	    s[DEBUGWRAP] = NUL;
	    fprintf(db,"PKT->[^A%s...](%d)\n",&s[1],n);
	    s[DEBUGWRAP] = c;
	} else {
#endif /* FULLPACKETS */
	    c = s[n-1];
	    s[n-1] = NUL;
	    fprintf(db,"PKT->[^A%s](%d)\n",&s[1],n);
	    s[n-1] = c;
#ifndef FULLPACKETS
	}
#endif /* FULLPACKETS */
    }
#ifdef USE_GETCHAR
    {					/* Send the packet with putchar() */
	register CHAR c; register int i;
	for (i = 0; i < n; i++) {
	    c = *s++;
	    if (putchar(c) == EOF) {
		logerr("ttol putchar");
		return(-1);
	    }
	}
    }
    fflush(stdout);			/* Push it out */
    return(n);
#else
    while (n > 0) {			/* Send the packet with write() */
	i = write(1,&s[m],n);		/* Allowing for partial results */
	if (i < 0) {
	    if (errno == EWOULDBLOCK)	/* and even no results at all.. */
	      continue;
	    logerr("ttol write");
	    return(-1);
	}
	if (i == n)
	  break;
	partial++;
	m += i;
	if (debug) fprintf(db,"ttol partial write %d (%d/%d)\n",i,m,len);
	n -= i;
    }
    if (partial) {
	m += i;
	if (debug) fprintf(db,"ttol partial write %d (%d/%d)\n",i,m,len);
	if (m != len) {
	    if (debug) fprintf(db,"ttol foulup %d != %d\n",m,len);
	    return(-1);
	}
    }
    return(len);
#endif /* USE_GETCHAR */
}

/* File Functions */

char ofile[MAXPATHLEN];			/* Output filename */
long filelength = -1L;

long
zchki(fn) char * fn; {			/* Check if file is readable */
    struct stat buf;
    if (!fn) return(-1);
    if (stat(fn,&buf) < 0)
      return(-1);
    errno = 0;
    if (access(fn,R_OK) < 0) {
	if (debug)
	  fprintf(db,"zchki access %s errno = %d\n",fn,errno);
	return(-1);
    }
    if (!S_ISREG(buf.st_mode)) {
	if (debug)
	  fprintf(db,"zchki %s is a directory",fn);
	return(-2);
    }
    return(buf.st_size);
}

int
zchko(fn) char *fn; {			/* Check write access */
    int i, x;
    char * s;

    if (!fn)				/* Defend against empty name */
      fn = "";
    if (!*fn)
      return(-1);
    if (!strcmp(fn,"/dev/null"))	/* Null device is OK. */
      return(0);
    if ((x = zchki(fn)) == -2)		/* An existing directory? */
      return(-1);
    s = fn;
    if (x < 0) {			/* If file does not exist */
	strncpy(work,fn,MAXPATHLEN);
	work[MAXPATHLEN] = NUL;
	s = work;
	for (i = (int)strlen(s); i > 0; i--) { /* Strip filename from right */
	    if (s[i-1] == '/') {	/* and check its directory */
		s[i-1] = NUL;
		break;
	    }
	}
	if (i == 0)
	  s = ".";
    }
    errno = 0;
    x = access(s,W_OK);			/* Check access of path. */
    if (debug) fprintf(db,"zchko(%s) x = %d errno = %d\n",s,x,errno);
    return((x < 0) ? -1 : 0);           /* and return. */
}

int
zopeni(name) char *name; {		/* Open existing file for input */
    ifp = fopen(name,"r");
    if (debug) fprintf(db,"zopeni %s: %d\n",name, ifp ? 0 : errno);
    filelength = zchki(name);
    if (filelength < 0)
      return((int)filelength);
    zincnt = 0;
    zinptr = zinbuf;
    return((ifp == NULL) ? -1 : 0);
}

int
zopeno(name) char *name; {		/* Open new file for output */
    errno = 0;
    ofp = fopen(name,"w");
    if (debug) fprintf(db,"zopeno %s: %d\n",name, ofp ? 0 : errno);
    if (ofp) {
	strncpy(ofile,name,MAXPATHLEN);
	ofile[MAXPATHLEN-1] = NUL;
	return(0);
    } else
      return(-1);
}

VOID					/* Local to remote file name */
zltor(lclnam,pktnam,maxlen) char *lclnam, *pktnam; int maxlen; {
    char *p, *np = NULL, *cp, *pp, c;
    char *dotp = NULL;
    char *dirp = NULL;
    int n = 0;

    if (debug)
      fprintf(db,"zltor %s: maxlen = %d, literal = %d\n",
	      lclnam,maxlen,literal);
    if (literal) {
	p = lclnam;
	dirp = p;
	while (*p) {
	    if (*p == '/') dirp = p+1;
	    p++;
	}
	strncpy(pktnam,dirp,maxlen);
    } else {
	for (p = lclnam; *p; p++) {	/* Point to name part */
	    if (*p == '/')
	      np = p;
	}
	if (np) {
	    np++;
	    if (!*np) np = lclnam;
	} else
	  np = lclnam;

	if (debug)
	  fprintf(db,"zltor np %s\n",np);

	pp = work;			/* Output buffer */
	for (cp = np, n = 0; *cp && n < maxlen; cp++,n++) {
	    c = *cp;
	    if (islower(c))		/* Uppercase letters */
	      *pp++ = toupper(c);	/* Change tilde to hyphen */
	    else if (c == '~')
	      *pp++ = '-';
	    else if (c == '#')		/* Change number sign to 'X' */
	      *pp++ = 'X';
	    else if (c == '*' || c == '?') /* Change wildcard chars to 'X' */
	      *pp++ = 'X';
	    else if (c == ' ')		/* Change space to underscore */
	      *pp++ = '_';
	    else if (c < ' ')		/* Change space and controls to 'X' */
	      *pp++ = 'X';
	    else if (c == '.') {	/* Change dot to underscore */
		dotp = pp;		/* Remember where we last did this */
		*pp++ = '_';
	    } else {
		if (c == '/')
		  dirp = pp;
		*pp++ = c;
	    }
	}
	*pp = NUL;			/* Tie it off. */
	if (dotp > dirp) *dotp = '.';	/* Restore last dot in file name */
	cp = pktnam;			/* If nothing before dot, */
	if (*work == '.') *cp++ = 'X';	/* insert 'X' */
	strncpy(cp,work,maxlen);
	cp[maxlen-1] = NUL;
    }
    if (debug)
      fprintf(db,"zltor result: %s\n",pktnam);
}

int
zbackup(fn) char * fn; {		/* Back up existing file */
    struct stat buf;
    int i, j, k, x, state, flag;
    char *p, newname[MAXPATHLEN+12];

    if (!fn)				/* Watch out for null pointers. */
      return(-1);
    if (!*fn)				/* And empty names. */
      return(-1);
    if (stat(fn,&buf) < 0)		/* If file doesn't exist */
      return(0);			/* no need to back it up. */

    i = strlen(fn);			/* Get length */
    if (i > MAXPATHLEN)			/* Guard buffer */
      i = MAXPATHLEN;
    if (debug)
      fprintf(db,"zbackup A %s: %d\n", fn, i);

    strncpy(work,fn,MAXPATHLEN);	/* Make pokeable copy of name */
    work[MAXPATHLEN] = NUL;
    p = work;				/* Strip any backup prefix */

    i--;
    for (flag = state = 0; (!flag && (i > 0)); i--) {
	switch (state) {
	  case 0:			/* State 0 - final char */
	    if (p[i] == '~')		/* Is tilde */
	      state = 1;		/* Switch to next state */
	    else			/* Otherwise */
	      flag = 1;			/* Quit - no backup suffix. */
	    break;
	  case 1:			/* State 1 - digits */
	    if (p[i] == '~'  && p[i-1] == '.') { /* Have suffix */
		p[i-1] = NUL;		/* Trim it */
		flag = 1;		/* done */
	    } else if (p[i] >= '0' && p[i] <= '9') { /* In number part */
		continue;		/* Keep going */
	    } else {			/* Something else */
		flag = 1;		/* Not a backup suffix - quit. */
	    }
	    break;
	}
    }
    if (debug)
      fprintf(db,"zbackup B %s\n", p);
    if (!p[0])
      p = fn;
    j = strlen(p);
    strncpy(newname,p,MAXPATHLEN);
    for (i = 1; i < 1000; i++) {	/* Search from 1 to 999 */
	if (i < 10)			/* Length of numeric part of suffix */
	  k = 1;
	else if (i < 100)
	  k = 2;
	else
	  k = 3;
	x = j;				/* Where to write suffix */
	if ((x + k + 3) > MAXPATHLEN)
	  x = MAXPATHLEN - k - 3;
	sprintf(&newname[x],".~%d~",i); /* Make a backup name */
	if (stat(newname,&buf) < 0) {	/* If it doesn't exist */
	    errno = 0;
	    if (link(fn,newname) <  0) { /* Rename old file to backup name */
		if (debug)
		  fprintf(db,"zbackup failed: link(%s): %d\n",newname,errno);
		return(-1);
	    } else if (unlink(fn) < 0) {
		if (debug)
		  fprintf(db,"zbackup failed: unlink(%s): %d\n",fn,errno);
		return(-1);
	    } else {
		if (debug)
		  fprintf(db,"zbackup %s: OK\n",newname);
		return(0);
	    }
	}
    }
    if (debug)
      fprintf(db,"zbackup failed: all numbers used\n");
    return(-1);
}

int					/* Remote to local filename */
zrtol(pktnam,lclnam,warn,maxlen) char *pktnam, *lclnam; int warn, maxlen; {
    int acase = 0, flag = 0, n = 0;
    char * p;

    if (literal) {
	strncpy(lclnam,pktnam,maxlen);
    } else {
	for (p = lclnam; *pktnam != '\0' && n < maxlen; pktnam++) {
	    if (*pktnam > SP) flag = 1;	/* Strip leading blanks and controls */
	    if (flag == 0 && *pktnam < '!')
	      continue;
	    if (isupper(*pktnam))	/* Check for mixed case */
	      acase |= 1;
	    else if (islower(*pktnam))
	      acase |= 2;
	    *p++ = *pktnam;
	    n++;
	}
	*p-- = NUL;			/* Terminate */
	while (*p < '!' && p > lclnam)	/* Strip trailing blanks & controls */
	  *p-- = '\0';

	if (!*lclnam) {			/* Nothing left? */
	    strncpy(lclnam,"NONAME",maxlen); /* do this... */
	} else if (acase == 1) {	/* All uppercase? */
	    p = lclnam;			/* So convert all letters to lower */
	    while (*p) {
		if (isupper(*p))
		  *p = tolower(*p);
		p++;
	    }
	}
    }
    if (warn) {
	if (zbackup(lclnam) < 0)
	  return(-1);
    }
    return(0);
}

int
zclosi() {				/* Close input file */
    int rc;
    rc = (fclose(ifp) == EOF) ? -1 : 0;
    ifp = NULL;
    return(rc);
}

int
zcloso(cx) int cx; {			/* Close output file */
    int rc;
    rc = (fclose(ofp) == EOF) ? -1 : 0;
    if (debug) fprintf(db,"zcloso(%s) cx = %d keep = %d\n", ofile, cx, keep);
    if (cx && !keep ) unlink(ofile);	/* Delete if incomplete */
    ofp = NULL;
    return(rc);
}

int
zfillbuf(text) int text; {		/* Refill input file buffer */
    if (zincnt < 1) {			/* Nothing in buffer - must refill */
	if (text) {			/* Text mode needs LF/CRLF handling */
	    int c;			/* Current character */
	    for (zincnt = 0;		/* Read a line */
		 zincnt < MAXRECORD - 1 && (c = getc(ifp)) != EOF && c != '\n';
		 zincnt++
		 ) {
		zinbuf[zincnt] = c;
	    }
	    if (c == '\n') {		/* Have newline. */
		zinbuf[zincnt++] = '\r'; /* Substitute CRLF */
		zinbuf[zincnt++] = c;
	    }
	} else {			/* Binary - just read raw buffers */
	    zincnt = fread(zinbuf, sizeof(char), MAXRECORD, ifp);
	}
	zinbuf[zincnt] = NUL;		/* Terminate. */
	if (zincnt == 0)		/* Check for EOF */
	  return(-1);
	zinptr = zinbuf;		/* Not EOF - reset pointer */
    }
#ifdef EXTRADEBUG				/* Voluminous debugging */
    if (debug) fprintf(db,"zfillbuf (%s) zincnt = %d\n",
		       text ? "text" : "binary",
		       zincnt
		       );
#endif /* EXTRADEBUG */
    zincnt--;				/* Return first byte. */
    return(*zinptr++ & 0xff);
}