dos_ls.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>

#include "bootsect.h"
#include "bpb.h"
#include "direntry.h"
#include "fat.h"
#include "dos.h"


void print_indent(int indent)
{
  int i;
  for (i = 0; i < indent; i++)
    printf(" ");
}

void follow_dir(uint16_t cluster, int indent,
		uint8_t *image_buf, struct bpb33* bpb)
{
    struct direntry *dirent;
    int d, i;
    dirent = (struct direntry*)cluster_to_addr(cluster, image_buf, bpb);
    while (1) {
	for (d = 0; d < bpb->bpbBytesPerSec * bpb->bpbSecPerClust; 
	     d += sizeof(struct direntry)) {
	    char name[9];
	    char extension[4];
	    uint32_t size;
	    uint16_t file_cluster;
	    name[8] = ' ';
	    extension[3] = ' ';
	    memcpy(name, &(dirent->deName[0]), 8);
	    memcpy(extension, dirent->deExtension, 3);
	    if (name[0] == SLOT_EMPTY)
		return;

	    /* skip over deleted entries */
	    if (((uint8_t)name[0]) == SLOT_DELETED)
		continue;

	    /* names are space padded - remove the spaces */
	    for (i = 8; i > 0; i--) {
		if (name[i] == ' ') 
		    name[i] = '\0';
		else 
		    break;
	    }

	    /* remove the spaces from extensions */
	    for (i = 3; i > 0; i--) {
		if (extension[i] == ' ') 
		    extension[i] = '\0';
		else 
		    break;
	    }

	    /* don't print "." or ".." directories */
	    if (strcmp(name, ".")==0) {
		dirent++;
		continue;
	    }
	    if (strcmp(name, "..")==0) {
		dirent++;
		continue;
	    }

	    if ((dirent->deAttributes & ATTR_VOLUME) != 0) {
		printf("Volume: %s\n", name);
	    } else if ((dirent->deAttributes & ATTR_DIRECTORY) != 0) {
	        print_indent(indent);
		printf("%s (directory)\n", name);
		file_cluster = getushort(dirent->deStartCluster);
		follow_dir(file_cluster, indent+2, image_buf, bpb);
	    } else {
		size = getulong(dirent->deFileSize);
	        print_indent(indent);
		printf("%s.%s (%u bytes)\n", 
		       name, extension, size);
	    }
	    dirent++;
	}
	if (cluster == 0) {
	    // root dir is special
	    dirent++;
	} else {
	    cluster = get_fat_entry(cluster, image_buf, bpb);
	    dirent = (struct direntry*)cluster_to_addr(cluster, 
						       image_buf, bpb);
	}
    }
}

void usage()
{
    fprintf(stderr, "Usage: dos_ls <imagename>\n");
    exit(1);
}

int main(int argc, char** argv)
{
    uint8_t *image_buf;
    int fd;
    struct bpb33* bpb;
    if (argc < 2 || argc > 2) {
	usage();
    }

    image_buf = mmap_file(argv[1], &fd);
    bpb = check_bootsector(image_buf);
    follow_dir(0, 0, image_buf, bpb);
    close(fd);
    exit(0);
}