/* * $Header: arcio.c,v 1.7 88/06/02 16:27:32 hyc Locked $ *//*  ARC - Archive utility - ARCIO    Version 2.50, created on 04/22/87 at 13:25:20(C) COPYRIGHT 1985,86 by System Enhancement Associates; ALL RIGHTS RESERVED    By:	 Thom Henderson    Description:	 This file contains the file I/O routines used to manipulate	 an archive.    Language:	 Computer Innovations Optimizing C86*/#include <stdio.h>#include "arc.h"#if	MTS#include <ctype.h>#endifvoid	abort();int	strlen(), free();intreadhdr(hdr, f)			/* read a header from an archive */	struct heads   *hdr;	/* storage for header */	FILE           *f;	/* archive to read header from */{#if	!MSDOS	unsigned char   dummy[28];	int             i;#endif	char            name[FNLEN];	/* filename buffer */	int             try = 0;/* retry counter */	static int      first = 1;	/* true only on first read */	if (!f)			/* if archive didn't open */		return 0;	/* then pretend it's the end */	if (feof(f))		/* if no more data */		return 0;	/* then signal end of archive */	if (fgetc(f) != ARCMARK) {	/* check archive validity */		if (warn) {			printf("An entry in %s has a bad header.", arcname);			nerrs++;		}		while (!feof(f)) {			try++;			if (fgetc(f) == ARCMARK) {				ungetc(hdrver = fgetc(f), f);				if (!(hdrver & 0x80) && hdrver <= ARCVER)					break;			}		}		if (feof(f) && first)			abort("%s is not an archive", arcname);		if (changing && warn)			abort("%s is corrupted -- changes disallowed", arcname);		if (warn)			printf("  %d bytes skipped.\n", try);		if (feof(f))			return 0;	}	hdrver = fgetc(f);	/* get header version */	if (hdrver & 0x80)	/* sign bit? negative? */		abort("Invalid header in archive %s", arcname);	if (hdrver == 0)		return 0;	/* note our end of archive marker */	if (hdrver > ARCVER) {		fread(name, sizeof(char), FNLEN, f);#if	MTS		atoe(name, strlen(name));#endif		printf("I don't know how to handle file %s in archive %s\n",		       name, arcname);		printf("I think you need a newer version of ARC.\n");		exit(1);	}	/* amount to read depends on header type */	if (hdrver == 1) {	/* old style is shorter */		fread(hdr, sizeof(struct heads) - sizeof(long int), 1, f);		hdrver = 2;	/* convert header to new format */		hdr->length = hdr->size;	/* size is same when not						 * packed */	} else#if	MSDOS		fread(hdr, sizeof(struct heads), 1, f);#else		fread(dummy, 27, 1, f);	for (i = 0; i < FNLEN; hdr->name[i] = dummy[i], i++);#if	MTS	(void) atoe(hdr->name, strlen(hdr->name));#endif	for (i = 0; i<4; hdr->size<<=8, hdr->size += dummy[16-i], i++);	hdr->date = (short) ((dummy[18] << 8) + dummy[17]);	hdr->time = (short) ((dummy[20] << 8) + dummy[19]);	hdr->crc = (short) ((dummy[22] << 8) + dummy[21]);	for (i = 0; i<4; hdr->length<<=8, hdr->length += dummy[26-i], i++);#endif	if (hdr->date > olddate	    || (hdr->date == olddate && hdr->time > oldtime)) {		olddate = hdr->date;		oldtime = hdr->time;	}	first = 0;	return 1;		/* we read something */}voidput_int(number, f)		/* write a 2 byte integer */	short           number;	FILE           *f;{	fputc((char) (number & 255), f);	fputc((char) (number >> 8), f);}voidput_long(number, f)		/* write a 4 byte integer */	long            number;	FILE           *f;{	put_int((short) (number & 0xFFFF), f);	put_int((short) (number >> 16), f);}voidwritehdr(hdr, f)		/* write a header to an archive */	struct heads   *hdr;	/* header to write */	FILE           *f;	/* archive to write to */{	fputc(ARCMARK, f);		/* write out the mark of ARC */	fputc(hdrver, f);	/* write out the header version */	if (!hdrver)		/* if that's the end */		return;		/* then write no more */#if	MSDOS	fwrite(hdr, sizeof(struct heads), 1, f);#else	/* byte/word ordering hassles... */#if	MTS	etoa(hdr->name, strlen(hdr->name));#endif	fwrite(hdr->name, 1, FNLEN, f);	put_long(hdr->size, f);	put_int(hdr->date, f);	put_int(hdr->time, f);	put_int(hdr->crc, f);	put_long(hdr->length, f);#endif	/* note the newest file for updating the archive timestamp */	if (hdr->date > arcdate	    || (hdr->date == arcdate && hdr->time > arctime)) {		arcdate = hdr->date;		arctime = hdr->time;	}}voidputc_tst(c, t)			/* put a character, with tests */	char            c;	/* character to output */	FILE           *t;	/* file to write to */{	c &= 0xff;	if (t)#if	UNIX		fputc(c, t);#else		if (fputc(c, t) == EOF)			abort("Write fail (disk full?)");#endif}/* * NOTE:  The filecopy() function is used to move large numbers of bytes from * one file to another.  This particular version has been modified to improve * performance in Computer Innovations C86 version 2.3 in the small memory * model.  It may not work as expected with other compilers or libraries, or * indeed with different versions of the CI-C86 compiler and library, or with * the same version in a different memory model. *  * The following is a functional equivalent to the filecopy() routine that * should work properly on any system using any compiler, albeit at the cost * of reduced performance: *  * filecopy(f,t,size)  *      FILE *f, *t; long size;  * {  *      while(size--) *              putc_tst(fgetc(f),t);  * } */#if	MSDOS#include <fileio2.h>filecopy(f, t, size)		/* bulk file copier */	FILE           *f, *t;	/* files from and to */	long            size;	/* bytes to copy */{	char           *buf;	/* buffer pointer */	char           *alloc();/* buffer allocator */	unsigned int    bufl;	/* buffer length */	unsigned int    coreleft();	/* space available reporter */	unsigned int    cpy;	/* bytes being copied */	long            floc, tloc, fseek();	/* file pointers, setter */	struct regval   reg;	/* registers for DOS calls */	if ((bufl = coreleft()) < 1000)	/* see how much space we have */		abort("Out of memory");	bufl -= 1000;		/* fudge factor for overhead */	if (bufl > 60000)		bufl = 60000;	/* avoid choking alloc() */	if (bufl > size)		bufl = size;	/* avoid wasting space */	buf = alloc(bufl);	/* allocate our buffer */	floc = fseek(f, 0L, 1);	/* reset I/O system */	tloc = fseek(t, 0L, 1);	segread(&reg.si);	/* set segment registers for DOS */	while (size > 0) {	/* while more to copy */		reg.ax = 0x3F00;/* read from handle */		reg.bx = filehand(f);		reg.cx = bufl < size ? bufl : size;	/* amount to read */		reg.dx = buf;		if (sysint21(&reg, &reg) & 1)			abort("Read fail");		cpy = reg.ax;	/* amount actually read */		reg.ax = 0x4000;/* write to handle */		reg.bx = filehand(t);		reg.cx = cpy;		reg.dx = buf;		sysint21(&reg, &reg);		if (reg.ax != cpy)			abort("Write fail (disk full?)");		size -= (long) cpy;	}	free(buf);		/* all done with buffer */}#elsevoidfilecopy(f, t, size)		/* bulk file copier */	FILE           *f, *t;	/* files from and to */	long            size;	/* bytes to copy */{	char           *buf;	/* buffer pointer */	char           *malloc();	/* buffer allocator */	unsigned int    bufl;	/* buffer length */	unsigned int    cpy;	/* bytes being copied */	bufl = 32760;	if (bufl > size)		bufl = size;	/* don't waste space */	buf = malloc(bufl);	while (size > 0) {		cpy = fread(buf, sizeof(char),			bufl < size ? bufl : (unsigned short) size, f);		if (fwrite(buf, sizeof(char), cpy, t) != cpy)			abort("Write fail (no space?)");		size -= cpy;	}	free(buf);}#endif