zreadline.c

Linux下ztelnet 的rz、sz源码

/*
  zreadline.c - line reading stuff for lrzsz
  Copyright (C) until 1998 Chuck Forsberg (OMEN Technology Inc)
  Copyright (C) 1994 Matt Porter
  Copyright (C) 1996, 1997 Uwe Ohse

  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, 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.

  originally written by Chuck Forsberg
*/
/* once part of lrz.c, taken out to be useful to lsz.c too */

#include "zglobal.h"

#include <stdlib.h>
#include <stdio.h>
#include <signal.h>
#include <ctype.h>
#include <errno.h>

#include "error.h"


/* Ward Christensen / CP/M parameters - Don't change these! */
#define TIMEOUT (-2)

static size_t readline_readnum;
static int readline_fd;
static char *readline_buffer;
int readline_left=0;
char *readline_ptr;

static RETSIGTYPE
zreadline_alarm_handler(int dummy LRZSZ_ATTRIB_UNUSED)
{
	/* doesn't need to do anything */
}

/*
 * This version of readline is reasonably well suited for
 * reading many characters.
 *
 * timeout is in tenths of seconds
 */
int 
readline_internal(unsigned int timeout)
{

	if (!no_timeout)
	{
		unsigned int n;
		n = timeout/10;
		if (n < 2 && timeout!=1)
			n = 3;
		else if (n==0)
			n=1;
		if (Verbose > 5)
			vstringf("Calling read: alarm=%d  Readnum=%d ",
			  n, readline_readnum);
		signal(SIGALRM, zreadline_alarm_handler); 
		alarm(n);
	}
	else if (Verbose > 5)
		vstringf("Calling read: Readnum=%d ",
		  readline_readnum);

	readline_ptr=readline_buffer;
	readline_left=read(readline_fd, readline_ptr, readline_readnum);
	if (!no_timeout)
		alarm(0);
	if (readline_left>0 && bytes_per_error) {
		static long ct=0;
		static int mod=1;
		ct+=readline_left;
		while (ct>bytes_per_error) {
			readline_ptr[ct % bytes_per_error]^=mod;
			ct-=bytes_per_error;
			mod++;
			if (mod==256)
				mod=1;
		}
	}
	if (Verbose > 5) {
		vstringf("Read returned %d bytes\n", readline_left);
		if (readline_left==-1)
			vstringf("errno=%d:%s\n", errno,strerror(errno));
		if (Verbose > 9 && readline_left>0) {
			int i,j;
			j=readline_left > 48 ? 48 : readline_left;
			vstring("    ");
			for (i=0;i<j;i++) {
				if (i%24==0 && i)
					vstring("\n    ");
				vstringf("%02x ", readline_ptr[i] & 0377);
			}
			vstringf("\n");
		}
	}
	if (readline_left < 1)
		return TIMEOUT;
	--readline_left;
	return (*readline_ptr++ & 0377);
}



void
readline_setup(int fd, size_t readnum, size_t bufsize)
{
	readline_fd=fd;
	readline_readnum=readnum;
	readline_buffer=malloc(bufsize > readnum ? bufsize : readnum);
	if (!readline_buffer)
		error(1,0,_("out of memory"));
}

void
readline_purge(void)
{
	readline_left=0;
	return;
}