#include <stdio.h>#include "msdos.h"long dir_chain[MAX_DIR_SECS];		/* chain of sectors in directory */unsigned char *dir_buf;			/* the directory buffer */int dir_dirty;				/* is the buffer dirty? */extern int dir_len, dir_start, clus_size, dir_entries, fat_error;extern unsigned int last_fat;/* * Read a directory entry, return a pointer a static structure. */struct directory *dir_read(num)int num;{	char *memcpy();	unsigned char *offset;	static struct directory dir;	offset = dir_buf + (num * MDIR_SIZE);	memcpy((char *) &dir, (char *) offset, MDIR_SIZE);	return(&dir);}/* * Fill in the global variable dir_chain[].  Argument is the starting * cluster number.  Returns -1 on error. */intfill_chain(num)unsigned int num;{	register int i, length;	unsigned int next, fat_decode();	unsigned char *offset;	char *realloc();	void perror(), exit(), disk_read(), dir_flush();	length = 0;	/* CONSTCOND */	while (1) {		dir_chain[length] = (long) (num - 2) * clus_size + dir_start + dir_len;		length++;					/* sectors, not clusters! */		for (i = 1; i < clus_size; i++) {			dir_chain[length] = dir_chain[length - 1] + 1L;			length++;		}		if (length >= MAX_DIR_SECS) {			fprintf(stderr, "fill_chain: directory too large\n");			return(-1);		}					/* get next cluster number */		next = fat_decode(num);		if (next == 1) {			fprintf(stderr, "fill_chain: FAT problem\n");			fat_error++;			return(-1);		}					/* end of cluster chain */		if (next >= last_fat)			break;		num = next;	}	if (dir_dirty)		dir_flush();					/* fill the dir_buf */	dir_buf = (unsigned char *) realloc(dir_buf, (unsigned int) length * MSECTOR_SIZE);	if (dir_buf == NULL) {		perror("fill_chain: realloc");		exit(1);	}	for (i = 0; i < length; i++) {		offset = dir_buf + (i * MSECTOR_SIZE);		disk_read(dir_chain[i], offset, MSECTOR_SIZE);	}	dir_entries = length * 16;	return(0);}/* * Reset the global variable dir_chain[] to the root directory. */voidreset_chain(code)int code;{	register int i;	char *malloc(), *realloc();	void disk_read(), dir_flush(), exit(), perror();	if (dir_dirty)		dir_flush();	for (i = 0; i < dir_len; i++)		dir_chain[i] = (long) dir_start + i;	if (code == OLD)		dir_buf = (unsigned char *) realloc(dir_buf, (unsigned int) dir_len * MSECTOR_SIZE);	else		dir_buf = (unsigned char *) malloc((unsigned int) dir_len * MSECTOR_SIZE);	if (dir_buf == NULL) {		perror("reset_chain: malloc");		exit(1);	}	disk_read((long) dir_start, dir_buf, dir_len * MSECTOR_SIZE);	dir_entries = dir_len * 16;	return;}/* * Get rid of spaces in an MSDOS 'raw' name (one that has come from the * directory structure) so that it can be used for regular expression * matching with a unix filename.  Also used to 'unfix' a name that has * been altered by dos_name().  Returns a pointer a static buffer. */char *unix_name(name, ext)unsigned char *name, *ext;{	char *s, tname[9], text[4], *strcpy(), *strcat(), *strchr();	char *strncpy();	static char ans[13];	strncpy(tname, (char *) name, 8);	tname[8] = '\0';	if (s = strchr(tname, ' '))		*s = '\0';	strncpy(text, (char *) ext, 3);	text[3] = '\0';	if (s = strchr(text, ' '))		*s = '\0';	if (*text) {		strcpy(ans, tname);		strcat(ans, ".");		strcat(ans, text);	}	else		strcpy(ans, tname);	return(ans);}