lhproc.c

汇编大全 中国矿业大学计算机学院 汇编实验5

/* LHPROC.C -- Test/List/Extract routine for LHX
 *
 * version 1.0 by Mark Armbrust, 15 April 1985   (IRS? Just say NO!)
 *
 * The code in this module is public domain -- do whatever you want with it */

#include <stdio.h>
#include <string.h>
#include <dos.h>
#include <conio.h>
#include <ctype.h>

#include "lhx.h"

/* private functions */

PRIVATE int  	ProcessData (FILE *, unsigned long, unsigned int, FILE *);
PRIVATE int  	ProcessCompData (FILE *, unsigned long, unsigned long,
								 unsigned int, FILE *);

/* private data */

PRIVATE char month[16][4] = {"0??","Jan","Feb","Mar","Apr","May","Jun","Jul",
							 "Aug","Sep","Oct","Nov","Dec","13?","14?","15?"};


PUBLIC int	Process	(arcfile, filenames)

FILE			*	arcfile;
struct fname	*	filenames;
{
struct lzhdir		header;
unsigned char		sum;
char				temp[100];
unsigned			errors, i;
unsigned long		next_hdr;
FILE			*	file;
char			*	p;
char			*	q;


switch (mode & MODES) {
	case TEST:
		printf ("\nTesting archive %s\n", name);
		break;
	case LIST:
		printf ("\nListing archive %s\n", name);
		break;
	case EXTRACT:
		printf ("\nExtracting archive %s\n", name);
		break;
	}

errors = 0;

if (header_start != -1)
	fseek (arcfile, header_start, SEEK_SET);

while ( ! feof (arcfile) ) {
	header.header_len = (char) fgetc (arcfile);
	if (feof (arcfile) )
		break;
	if ( header_start == -1 && header.header_len == 0)
		continue;

	if ( header_start == -1 && (header.header_len < 21 || header.header_len > 98)) {
		printf ("  invalid file header -- skipping remainder of file\n");
		++errors;
		break;
		}

	if (header.header_len > 98)
		header.header_len = 98;

	if ( ! fread (&header.header_sum, header.header_len + 1, 1, arcfile) &&
			 header_start == -1) {
		printf ("  unexpected eof\n");
		++errors;
		break;
		}

	i = header.name_len;
	if (i > header.header_len - 22)
		i = header.header_len - 22;
	strncpy (temp, header.filename, i);
	temp[i] = '\0';

	next_hdr = ftell (arcfile) + header.data_size;

	if (file_name[0] || MatchAny (temp, filenames)) {

		for (sum=0, i=0; i<header.header_len; ++i)
			sum += ((char *)&header)[i+2];

		header.file_CRC = *((int *)&header.filename[header.name_len]);

		if (mode & LIST) {
			printf ("%c %c%cr%c%c%8ld /%8ld  %2d %3s %.2d  %.2d:%.2d:%.2d   %s\n",
					(header.header_sum == sum) ? ' ' : '?',
					(header.file_attr & _A_SYSTEM) ? 's' : '-',
					(header.file_attr & _A_HIDDEN) ? 'h' : '-',
					(header.file_attr & _A_RDONLY) ? '-' : 'w',
					(header.file_attr & _A_ARCH) ? '-' : 'a',
					header.file_size,
					header.data_size,
					header.file_date & 0x001F,
					month[(header.file_date & 0x01E0) >> 5],
					(((header.file_date & 0xFE00) >> 9) + 80) % 100,
					(header.file_time & 0xF800) >> 11,
					(header.file_time & 0x07E0) >> 5,
					(header.file_time & 0x001F) << 1,
					temp);
			}
		else {
			if (file_name[0])
				printf ("  %s -- ", file_name);
			else
				printf ("  %s -- ", temp);

			if ((mode & TEST) && header.header_sum != sum) {
				printf ("bad file header, ");
				++errors;
				}

			if (mode & TEST)
				file = 0;
			else {
				p = temp;
				if (q = strrchr (p, '\\')) p = q + 1;
				if (q = strrchr (p, '/')) p = q + 1;

				if (file_name[0])
					p = file_name;

				if ( file = fopen (p, "r")) {
					fclose (file);
					do {
						fprintf (stderr, "\nfile exists; overwrite (y/n)? \007");
						i = getche();
						fprintf (stderr, "\n");
						if ( (i=toupper(i)) == 'N')
							goto NEXT_FILE;
						}
					while (i != 'Y');
					}

				if ( ! (file = fopen (p, "wb")) ) {
					printf ("could not create file '%s'\n", p);
					goto NEXT_FILE;
					}
				}

			if (file_start != -1)
				fseek (arcfile, file_start, SEEK_SET);
			if (file_size != -1)
				header.data_size = header.file_size = file_size;

			if (file_type == 0 || strncmp (header.method, "-lh0-", 5) == 0)
				errors += ProcessData (arcfile, header.file_size, header.file_CRC, file);
			else if (file_type == 1 || strncmp (header.method, "-lh1-", 5) == 0)
				errors += ProcessCompData (arcfile, header.data_size, header.file_size,
										header.file_CRC, file);
			else {
				printf ("unknown compression method -- file skipped\n");
				++errors;
				}
			if (file)
				fclose (file);
			}
		}
NEXT_FILE:
	if (file_start != -1)				/* if we had to tell it where the data starts,	*/
		fseek (arcfile, -1L, SEEK_CUR);	/* assume the next header immediatly follows.	*/
	else
		fseek (arcfile, next_hdr, SEEK_SET);

	header_start = -1;
	file_start = -1;
	file_size = -1;
	file_type = -1;

	if (file_name[0])
		break;
	}
if ((mode & TEST) || errors)
	printf ("%d error%s detected\n", errors, (errors==1)?"":"s");
return (errors);
}



PRIVATE int  	ProcessData (arcfile, data_size, file_CRC, file)

FILE			*	arcfile;
unsigned long		data_size;
unsigned int  		file_CRC;
FILE			*	file;
{
int  	count;

crccode = 0;
while (data_size) {
	if (data_size < BUFF_LEN)
		count = (int) data_size;
	else
		count = BUFF_LEN;

	if ( ! fread (buffer, count, 1, arcfile) ) {
		printf ("unexpected eof\n");
		return 1;
		}

	addbfcrc (buffer, count);

	if (file)
		if ( ! fwrite (buffer, count, 1, file) ) {
			printf ("write error; disk full?\n");
			return 1;
			}

	data_size -= count;
	}

if (crccode == file_CRC) {
	printf ("%s OK\n", (mode&TEST) ? "data" : "extracted");
	return 0;
	}
printf ("%s CRC error\n", (mode&TEST) ? "data" : "extracted with");
return 1;
}



PRIVATE int  	ProcessCompData (arcfile, data_size, file_size, file_CRC, file)

FILE			*	arcfile;
unsigned long		data_size;
unsigned long 		file_size;
unsigned int  		file_CRC;
FILE			*	file;
{

crccode = 0;
textsize = file_size;
infile = arcfile;
outfile = file;

Decode ();

if (crccode == file_CRC) {
	printf ("%s OK\n", (mode&TEST) ? "data" : "extracted");
	return 0;
	}
printf ("%s CRC error\n", (mode&TEST) ? "data" : "extracted with");
return 1;
}