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#include <stdio.h>
#include <stdlib.h>
#include <f65.h>
#include "unalf.h"
#include "addrs.h"
static int headers_read = 0;
static void die_arc(void) {
fprintf(stderr, "%s: this is an ARC file, not ALF\n", self);
exit(1);
}
static void die_not_alf(void) {
fprintf(stderr, "%s: not an ALF file\n", self);
exit(1);
}
static void eof_junk(void) {
fprintf(stderr, "%s: junk at EOF (ignoring)\n", self);
}
static void check_hdr_size(const char *name, unsigned long size) {
const char *desc;
/* fits on a double-density disk? */
if(size < 184320)
return;
/* >= 16MB files are impossible because the decrunch algorithm
ignores the high byte of the 4-byte length. */
if(size >= 16777216L)
desc = "impossibly large (>=16MB)";
/* >1MB files are possible (e.g. with a hard drive on SpartaDOS X)
but exceedingly rare in the Atari world. */
else if(size > 1048576L)
desc = "suspiciously large (>1MB)";
else
desc = "too large for a floppy disk (>180KB)";
fprintf(stderr, "%s: header #%d %s size is %s.\n",
self, headers_read, name, desc);
}
static void sanity_check_header(void) {
check_hdr_size("original", getquad(alf_hdr_origsize0));
check_hdr_size("compressed", getquad(alf_hdr_compsize0));
}
/* return 1 if a header is read, 0 if not */
int read_alf_header(void) {
u8 h1, h2;
int bytes;
bytes = fread(mem + alf_header, 1, 29, in_file);
if(!bytes) {
if(headers_read)
return 0;
else
die_not_alf();
} else if(bytes < 29) {
if(headers_read) {
eof_junk();
return 0;
} else {
die_not_alf();
}
}
h1 = mem[alf_header];
h2 = mem[alf_hdr_sig];
if(h1 == 0x1a) {
if(h2 < 0x0f) die_arc();
if(h2 == 0x0f) {
headers_read++;
sanity_check_header();
return 1; /* signature matches */
}
}
if(headers_read)
eof_junk();
else
die_not_alf();
return 0;
}
/* read buf_len_l/h bytes into buf_adr_l/h, then store the number
of bytes actually read in buf_len_l/h. TODO: what about EOF? */
void readblock(void) {
int bytes, len, bufadr;
u8 *buf;
bufadr = dpeek(buf_adr_l);
buf = mem + bufadr;
len = dpeek(buf_len_l);
// fprintf(stderr, "readblock, bufadr = $%04x, len = $%04x\n", bufadr, len);
bytes = fread(buf, 1, len, in_file);
dpoke(buf_len_l, bytes);
}
int is_text_file(char *fn) {
if(globmatch("*.txt", fn)) return 1;
if(globmatch("*.doc", fn)) return 1;
if(globmatch("*.lst", fn)) return 1;
return 0;
}
/* mirror of readblock() */
void writeblock(void) {
int i, bytes, len, bufadr;
u8 *buf;
extern char *out_filename;
bufadr = dpeek(buf_adr_l);
buf = mem + bufadr;
len = dpeek(buf_len_l);
if(opts.txtconv) {
if(opts.txtconv > 1 || is_text_file(out_filename))
for(i = 0; i < len; i++)
if(buf[i] == 0x9b) buf[i] = '\n';
}
// fprintf(stderr, "writeblock, bufadr = $%04x, len = $%04x\n", bufadr, len);
bytes = fwrite(buf, 1, len, out_file);
dpoke(buf_len_l, bytes);
}
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