mpw-tools/OverlayIIgs.c

237 lines
3.1 KiB
C
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2013-07-29 06:02:50 +00:00
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include "OverlayIIgs-flags.h"
int tox(char c)
{
c |= 0x20;
if (c >='0' && c <= '9') return c - '0';
if (c >= 'a' && c <= 'f') return c - 'a' + 10;
return 0;
}
off_t hex(const char *in)
{
off_t rv = 0;
int i;
for (i = 0; ; ++i)
{
off_t tmp;
char c;
c = *in++;
if (!c) break;
if (!isxdigit(c)) return -1;
tmp = rv;
rv <<= 4;
rv |= tox(c);
// numver too large.
if (rv < tmp)
{
return -1;
}
}
if (i == 0) return -1;
return rv;
}
off_t dec(const char *in)
{
off_t rv = 0;
int i;
for (i = 0; ; ++i)
{
off_t tmp;
char c;
c = *in++;
if (!c) break;
if (!isdigit(c)) return -1;
tmp = rv;
rv = rv * 10;
rv += c - '0';
// numver too large.
if (rv < tmp)
{
return -1;
}
}
if (i == 0) return -1;
return rv;
}
off_t getnum(const char *cp)
{
if (!cp) return -1;
if (cp[0] == '$')
{
return hex(cp + 1);
}
if (cp[0] == '0' && cp[1] == 'x')
{
return hex(cp + 2);
}
return dec(cp);
}
int seek_to(int fd, off_t address)
{
// posix lseek(2) will seek past the eof and zero-fill
// when a write occurs.
// mpw lseek will fail (ENXIO) in such situations.
// SetEOF will not zero-fill.
// to compensate, manually zero-fill to the address
// if address > eof.
off_t eof;
eof = lseek(fd, 0, SEEK_END);
if (eof < 0)
return -1;
while (eof < address)
{
static char buffer[512] = { 0 };
off_t size = address - eof;
if (size > 512) size = 512;
size = write(fd, buffer, size);
if (size < 0) return -1;
eof += size;
}
eof = lseek(fd, address, SEEK_SET);
if (eof < 0)
return -1;
return 0;
}
int main(int argc, char **argv)
{
char *src;
char *dest;
int srcFD, destFD;
off_t address;
int rv;
argc = FlagsParse(argc, argv);
if (argc != 3)
{
FlagsHelp();
return 1;
}
if (!flags._a)
{
FlagsHelp();
return 1;
}
address = getnum(flags._a);
if (address == -1)
{
fprintf(stderr, "Invalid address: %s\n", flags._a);
return 1;
}
src = argv[1];
dest = argv[2];
srcFD = open(src, O_RDONLY | O_BINARY);
if (srcFD < 0)
{
fprintf(stderr, "Unable to open input file %s: %s",
src, strerror(errno));
return 1;
}
destFD = open(dest, O_WRONLY | O_CREAT | O_BINARY);
if (destFD < 0)
{
fprintf(stderr, "Unable to open input file %s: %s",
dest, strerror(errno));
close(srcFD);
return 1;
}
//if (lseek(destFD, address, SEEK_SET) < 0)
if (seek_to(destFD, address) < 0)
{
fprintf(stderr, "Error seeking %s: %s",
dest, strerror(errno));
close(srcFD);
close(destFD);
return 1;
}
// copy it
rv = 0;
for (;;)
{
unsigned char buffer[4096];
ssize_t rsize;
ssize_t wsize;
rsize = read(srcFD, buffer, 4096);
if (rsize == 0) break;
if (rsize < 0)
{
fprintf(stderr, "Error reading %s: %s\n",
src, strerror(errno));
rv = 1;
break;
}
wsize = write(destFD, buffer, rsize);
if (wsize < 0 || wsize != rsize)
{
fprintf(stderr, "Error writing %s: %s\n",
dest, strerror(errno));
rv = 1;
break;
}
}
close(srcFD);
close(destFD);
return rv;
}