/* $Id$ */
/*
* Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "config.h"
#include <sys/types.h>
#ifdef HAVE_MMAP
#include <sys/stat.h>
#include <sys/mman.h>
#endif
#include <assert.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
/*
* The read_whole_file() and resize_buf() functions are copied from
* read.c, including all dependency code.
*/
enum enc {
ENC_UTF_8, /* UTF-8 */
ENC_US_ASCII, /* US-ASCII */
ENC_LATIN_1, /* Latin-1 */
ENC__MAX
};
struct buf {
char *buf; /* binary input buffer */
size_t sz; /* size of binary buffer */
size_t offs; /* starting buffer offset */
};
struct encode {
const char *name;
int (*conv)(const struct buf *);
};
static int cue_enc(const struct buf *, size_t *, enum enc *);
static int conv_latin_1(const struct buf *);
static int conv_us_ascii(const struct buf *);
static int conv_utf_8(const struct buf *);
static int read_whole_file(const char *, int,
struct buf *, int *);
static void resize_buf(struct buf *, size_t);
static void usage(void);
static const struct encode encs[ENC__MAX] = {
{ "utf-8", conv_utf_8 }, /* ENC_UTF_8 */
{ "us-ascii", conv_us_ascii }, /* ENC_US_ASCII */
{ "latin-1", conv_latin_1 }, /* ENC_LATIN_1 */
};
static const char *progname;
static void
usage(void)
{
fprintf(stderr, "usage: %s "
"[-D enc] "
"[-e ENC] "
"[file]\n", progname);
}
static int
conv_latin_1(const struct buf *b)
{
size_t i;
unsigned char cu;
const char *cp;
cp = b->buf + (int)b->offs;
/*
* Latin-1 falls into the first 256 code-points of Unicode, so
* there's no need for any sort of translation. Just make the
* 8-bit characters use the Unicode escape.
* Note that binary values 128 < v < 160 are passed through
* unmodified to mandoc.
*/
for (i = b->offs; i < b->sz; i++) {
cu = (unsigned char)*cp++;
cu < 160U ? putchar(cu) : printf("\\[u%.4X]", cu);
}
return(1);
}
static int
conv_us_ascii(const struct buf *b)
{
/*
* US-ASCII has no conversion since it falls into the first 128
* bytes of Unicode.
*/
fwrite(b->buf, 1, b->sz, stdout);
return(1);
}
static int
conv_utf_8(const struct buf *b)
{
int state, be;
unsigned int accum;
size_t i;
unsigned char cu;
const char *cp;
const long one = 1L;
cp = b->buf + (int)b->offs;
state = 0;
accum = 0U;
be = 0;
/* Quick test for big-endian value. */
if ( ! (*((const char *)(&one))))
be = 1;
for (i = b->offs; i < b->sz; i++) {
cu = (unsigned char)*cp++;
if (state) {
if ( ! (cu & 128) || (cu & 64)) {
/* Bad sequence header. */
return(0);
}
/* Accept only legitimate bit patterns. */
if (cu > 191 || cu < 128) {
/* Bad in-sequence bits. */
return(0);
}
accum |= (cu & 63) << --state * 6;
/*
* Accum is held in little-endian order as
* stipulated by the UTF-8 sequence coding. We
* need to convert to a native big-endian if our
* architecture requires it.
*/
if (0 == state && be)
accum = (accum >> 24) |
((accum << 8) & 0x00FF0000) |
((accum >> 8) & 0x0000FF00) |
(accum << 24);
if (0 == state) {
accum < 128U ? putchar(accum) :
printf("\\[u%.4X]", accum);
accum = 0U;
}
} else if (cu & (1 << 7)) {
/*
* Entering a UTF-8 state: if we encounter a
* UTF-8 bitmask, calculate the expected UTF-8
* state from it.
*/
for (state = 0; state < 7; state++)
if ( ! (cu & (1 << (7 - state))))
break;
/* Accept only legitimate bit patterns. */
switch (state) {
case (4):
if (cu <= 244 && cu >= 240) {
accum = (cu & 7) << 18;
break;
}
/* Bad 4-sequence start bits. */
return(0);
case (3):
if (cu <= 239 && cu >= 224) {
accum = (cu & 15) << 12;
break;
}
/* Bad 3-sequence start bits. */
return(0);
case (2):
if (cu <= 223 && cu >= 194) {
accum = (cu & 31) << 6;
break;
}
/* Bad 2-sequence start bits. */
return(0);
default:
/* Bad sequence bit mask. */
return(0);
}
state--;
} else
putchar(cu);
}
if (0 != state) {
/* Bad trailing bits. */
return(0);
}
return(1);
}
static void
resize_buf(struct buf *buf, size_t initial)
{
buf->sz = buf->sz > initial / 2 ?
2 * buf->sz : initial;
buf->buf = realloc(buf->buf, buf->sz);
if (NULL == buf->buf) {
perror(NULL);
exit(EXIT_FAILURE);
}
}
static int
read_whole_file(const char *f, int fd,
struct buf *fb, int *with_mmap)
{
size_t off;
ssize_t ssz;
#ifdef HAVE_MMAP
struct stat st;
if (-1 == fstat(fd, &st)) {
perror(f);
return(0);
}
/*
* If we're a regular file, try just reading in the whole entry
* via mmap(). This is faster than reading it into blocks, and
* since each file is only a few bytes to begin with, I'm not
* concerned that this is going to tank any machines.
*/
if (S_ISREG(st.st_mode) && st.st_size >= (1U << 31)) {
fprintf(stderr, "%s: input too large\n", f);
return(0);
}
if (S_ISREG(st.st_mode)) {
*with_mmap = 1;
fb->sz = (size_t)st.st_size;
fb->buf = mmap(NULL, fb->sz, PROT_READ, MAP_SHARED, fd, 0);
if (fb->buf != MAP_FAILED)
return(1);
}
#endif
/*
* If this isn't a regular file (like, say, stdin), then we must
* go the old way and just read things in bit by bit.
*/
*with_mmap = 0;
off = 0;
fb->sz = 0;
fb->buf = NULL;
for (;;) {
if (off == fb->sz && fb->sz == (1U << 31)) {
fprintf(stderr, "%s: input too large\n", f);
break;
}
if (off == fb->sz)
resize_buf(fb, 65536);
ssz = read(fd, fb->buf + (int)off, fb->sz - off);
if (ssz == 0) {
fb->sz = off;
return(1);
}
if (ssz == -1) {
perror(f);
break;
}
off += (size_t)ssz;
}
free(fb->buf);
fb->buf = NULL;
return(0);
}
static int
cue_enc(const struct buf *b, size_t *offs, enum enc *enc)
{
const char *ln, *eoln, *eoph;
size_t sz, phsz, nsz;
int i;
ln = b->buf + (int)*offs;
sz = b->sz - *offs;
/* Look for the end-of-line. */
if (NULL == (eoln = memchr(ln, '\n', sz)))
return(-1);
/* Set next-line marker. */
*offs = (size_t)((eoln + 1) - b->buf);
/* Check if we have the correct header/trailer. */
if ((sz = (size_t)(eoln - ln)) < 10 ||
memcmp(ln, ".\\\" -*-", 7) ||
memcmp(eoln - 3, "-*-", 3))
return(0);
/* Move after the header and adjust for the trailer. */
ln += 7;
sz -= 10;
while (sz > 0) {
while (sz > 0 && ' ' == *ln) {
ln++;
sz--;
}
if (0 == sz)
break;
/* Find the end-of-phrase marker (or eoln). */
if (NULL == (eoph = memchr(ln, ';', sz)))
eoph = eoln - 3;
else
eoph++;
/* Only account for the "coding" phrase. */
if ((phsz = (size_t)(eoph - ln)) < 7 ||
strncasecmp(ln, "coding:", 7)) {
sz -= phsz;
ln += phsz;
continue;
}
sz -= 7;
ln += 7;
while (sz > 0 && ' ' == *ln) {
ln++;
sz--;
}
if (0 == sz)
break;
/* Check us against known encodings. */
for (i = 0; i < (int)ENC__MAX; i++) {
nsz = strlen(encs[i].name);
if (phsz < nsz)
continue;
if (strncasecmp(ln, encs[i].name, nsz))
continue;
*enc = (enum enc)i;
return(1);
}
/* Unknown encoding. */
*enc = ENC__MAX;
return(1);
}
return(0);
}
int
main(int argc, char *argv[])
{
int i, ch, map, fd, rc;
struct buf b;
const char *fn;
enum enc enc, def;
unsigned char bom[3] = { 0xEF, 0xBB, 0xBF };
size_t offs;
extern int optind;
extern char *optarg;
progname = strrchr(argv[0], '/');
if (progname == NULL)
progname = argv[0];
else
++progname;
fn = "<stdin>";
fd = STDIN_FILENO;
rc = EXIT_FAILURE;
enc = def = ENC__MAX;
map = 0;
memset(&b, 0, sizeof(struct buf));
while (-1 != (ch = getopt(argc, argv, "D:e:rdvh")))
switch (ch) {
case ('D'):
/* FALLTHROUGH */
case ('e'):
for (i = 0; i < (int)ENC__MAX; i++) {
if (strcasecmp(optarg, encs[i].name))
continue;
break;
}
if (i < (int)ENC__MAX) {
if ('D' == ch)
def = (enum enc)i;
else
enc = (enum enc)i;
break;
}
fprintf(stderr, "%s: Bad encoding\n", optarg);
return(EXIT_FAILURE);
case ('r'):
/* FALLTHROUGH */
case ('d'):
/* FALLTHROUGH */
case ('v'):
/* Compatibility with GNU preconv. */
break;
case ('h'):
/* Compatibility with GNU preconv. */
/* FALLTHROUGH */
default:
usage();
return(EXIT_FAILURE);
}
argc -= optind;
argv += optind;
/*
* Open and read the first argument on the command-line.
* If we don't have one, we default to stdin.
*/
if (argc > 0) {
fn = *argv;
fd = open(fn, O_RDONLY, 0);
if (-1 == fd) {
perror(fn);
return(EXIT_FAILURE);
}
}
if ( ! read_whole_file(fn, fd, &b, &map))
goto out;
/* Try to read the UTF-8 BOM. */
if (ENC__MAX == enc)
if (b.sz > 3 && 0 == memcmp(b.buf, bom, 3)) {
b.offs = 3;
enc = ENC_UTF_8;
}
/* Try reading from the "-*-" cue. */
if (ENC__MAX == enc) {
offs = b.offs;
ch = cue_enc(&b, &offs, &enc);
if (0 == ch)
ch = cue_enc(&b, &offs, &enc);
}
/*
* No encoding has been detected.
* Thus, we either fall into our default encoder, if specified,
* or use Latin-1 if all else fails.
*/
if (ENC__MAX == enc)
enc = ENC__MAX == def ? ENC_LATIN_1 : def;
if ( ! (*encs[(int)enc].conv)(&b)) {
fprintf(stderr, "%s: Bad encoding\n", fn);
goto out;
}
rc = EXIT_SUCCESS;
out:
#ifdef HAVE_MMAP
if (map)
munmap(b.buf, b.sz);
else
#endif
free(b.buf);
if (fd > STDIN_FILENO)
close(fd);
return(rc);
}
