2 * Copyright (c) Ian F. Darwin 1986-1995.
3 * Software written by Ian F. Darwin and others;
4 * maintained 1995-present by Christos Zoulas and others.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice immediately at the beginning of the file, without modification,
11 * this list of conditions, and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * ASCII magic -- try to detect text encoding.
31 * Extensively modified by Eric Fischer <enf@pobox.com> in July, 2000,
32 * to handle character codes other than ASCII on a unified basis.
38 FILE_RCSID("@(#)$File: ascmagic.c,v 1.104 2019/05/07 02:27:11 christos Exp $")
50 #define MAXLINELEN 300 /* longest sane line length */
51 #define ISSPC(x) ((x) == ' ' || (x) == '\t' || (x) == '\r' || (x) == '\n' \
52 || (x) == 0x85 || (x) == '\f')
54 private unsigned char *encode_utf8(unsigned char *, size_t, unichar *, size_t);
55 private size_t trim_nuls(const unsigned char *, size_t);
58 * Undo the NUL-termination kindly provided by process()
59 * but leave at least one byte to look at
62 trim_nuls(const unsigned char *buf, size_t nbytes)
64 while (nbytes > 1 && buf[nbytes - 1] == '\0')
71 file_ascmagic(struct magic_set *ms, const struct buffer *b, int text)
78 const char *code = NULL;
79 const char *code_mime = NULL;
80 const char *type = NULL;
83 bb.flen = trim_nuls(CAST(const unsigned char *, b->fbuf), b->flen);
85 * Avoid trimming at an odd byte if the original buffer was evenly
86 * sized; this avoids losing the last character on UTF-16 LE text
88 if ((bb.flen & 1) && !(b->flen & 1))
91 /* If file doesn't look like any sort of text, give up. */
92 if (file_encoding(ms, &bb, &ubuf, &ulen, &code, &code_mime,
96 rv = file_ascmagic_with_encoding(ms, &bb,
97 ubuf, ulen, code, type, text);
105 file_ascmagic_with_encoding(struct magic_set *ms,
106 const struct buffer *b, unichar *ubuf, size_t ulen, const char *code,
107 const char *type, int text)
110 const unsigned char *buf = CAST(const unsigned char *, b->fbuf);
111 size_t nbytes = b->flen;
112 unsigned char *utf8_buf = NULL, *utf8_end;
115 int mime = ms->flags & MAGIC_MIME;
116 int need_separator = 0;
118 const char *subtype = NULL;
119 const char *subtype_mime = NULL;
122 int has_backspace = 0;
131 size_t last_line_end = CAST(size_t, -1);
132 int has_long_lines = 0;
134 nbytes = trim_nuls(buf, nbytes);
136 /* If we have fewer than 2 bytes, give up. */
142 if (ulen > 0 && (ms->flags & MAGIC_NO_CHECK_SOFT) == 0) {
143 /* Convert ubuf to UTF-8 and try text soft magic */
144 /* malloc size is a conservative overestimate; could be
145 improved, or at least realloced after conversion. */
147 if ((utf8_buf = CAST(unsigned char *, malloc(mlen))) == NULL) {
148 file_oomem(ms, mlen);
151 if ((utf8_end = encode_utf8(utf8_buf, mlen, ubuf, ulen))
154 buffer_init(&bb, b->fd, &b->st, utf8_buf,
155 CAST(size_t, utf8_end - utf8_buf));
157 if ((rv = file_softmagic(ms, &bb, NULL, NULL,
158 TEXTTEST, text)) == 0)
163 if ((ms->flags & (MAGIC_APPLE|MAGIC_EXTENSION))) {
164 rv = rv == -1 ? 0 : 1;
168 if ((ms->flags & (MAGIC_APPLE|MAGIC_EXTENSION)))
171 /* Now try to discover other details about the file. */
172 for (i = 0; i < ulen; i++) {
173 if (ubuf[i] == '\n') {
182 seen_cr = (ubuf[i] == '\r');
186 if (ubuf[i] == 0x85) { /* X3.64/ECMA-43 "next line" character */
191 /* If this line is _longer_ than MAXLINELEN, remember it. */
192 if (i > last_line_end + MAXLINELEN)
195 if (ubuf[i] == '\033')
201 /* Beware, if the data has been truncated, the final CR could have
202 been followed by a LF. If we have ms->bytes_max bytes, it indicates
203 that the data might have been truncated, probably even before
204 this function was called. */
205 if (seen_cr && nbytes < ms->bytes_max)
208 if (strcmp(type, "binary") == 0) {
212 len = file_printedlen(ms);
214 if ((mime & MAGIC_MIME_TYPE) != 0) {
217 * Softmagic printed something, we
218 * are either done, or we need a separator
220 if ((ms->flags & MAGIC_CONTINUE) == 0) {
224 if (need_separator && file_separator(ms) == -1)
228 if (file_printf(ms, "%s", subtype_mime) == -1)
231 if (file_printf(ms, "text/plain") == -1)
237 switch (file_replace(ms, " text$", ", ")) {
239 switch (file_replace(ms, " text executable$",
242 if (file_printf(ms, ", ") == -1)
259 if (file_printf(ms, "%s", code) == -1)
263 if (file_printf(ms, " %s", subtype) == -1)
267 if (file_printf(ms, " %s", type) == -1)
271 if (file_printf(ms, " executable") == -1)
275 if (file_printf(ms, ", with very long lines") == -1)
279 * Only report line terminators if we find one other than LF,
280 * or if we find none at all.
282 if ((n_crlf == 0 && n_cr == 0 && n_nel == 0 && n_lf == 0) ||
283 (n_crlf != 0 || n_cr != 0 || n_nel != 0)) {
284 if (file_printf(ms, ", with") == -1)
287 if (n_crlf == 0 && n_cr == 0 && n_nel == 0 && n_lf == 0) {
288 if (file_printf(ms, " no") == -1)
292 if (file_printf(ms, " CRLF") == -1)
294 if (n_cr || n_lf || n_nel)
295 if (file_printf(ms, ",") == -1)
299 if (file_printf(ms, " CR") == -1)
302 if (file_printf(ms, ",") == -1)
306 if (file_printf(ms, " LF") == -1)
309 if (file_printf(ms, ",") == -1)
313 if (file_printf(ms, " NEL") == -1)
317 if (file_printf(ms, " line terminators") == -1)
322 if (file_printf(ms, ", with escape sequences") == -1)
325 if (file_printf(ms, ", with overstriking") == -1)
336 * Encode Unicode string as UTF-8, returning pointer to character
337 * after end of string, or NULL if an invalid character is found.
339 private unsigned char *
340 encode_utf8(unsigned char *buf, size_t len, unichar *ubuf, size_t ulen)
343 unsigned char *end = buf + len;
345 for (i = 0; i < ulen; i++) {
346 if (ubuf[i] <= 0x7f) {
349 *buf++ = CAST(unsigned char, ubuf[i]);
350 } else if (ubuf[i] <= 0x7ff) {
353 *buf++ = CAST(unsigned char, (ubuf[i] >> 6) + 0xc0);
354 *buf++ = CAST(unsigned char, (ubuf[i] & 0x3f) + 0x80);
355 } else if (ubuf[i] <= 0xffff) {
358 *buf++ = CAST(unsigned char, (ubuf[i] >> 12) + 0xe0);
359 *buf++ = CAST(unsigned char, ((ubuf[i] >> 6) & 0x3f) + 0x80);
360 *buf++ = CAST(unsigned char, (ubuf[i] & 0x3f) + 0x80);
361 } else if (ubuf[i] <= 0x1fffff) {
364 *buf++ = CAST(unsigned char, (ubuf[i] >> 18) + 0xf0);
365 *buf++ = CAST(unsigned char, ((ubuf[i] >> 12) & 0x3f) + 0x80);
366 *buf++ = CAST(unsigned char, ((ubuf[i] >> 6) & 0x3f) + 0x80);
367 *buf++ = CAST(unsigned char, (ubuf[i] & 0x3f) + 0x80);
368 } else if (ubuf[i] <= 0x3ffffff) {
371 *buf++ = CAST(unsigned char, (ubuf[i] >> 24) + 0xf8);
372 *buf++ = CAST(unsigned char, ((ubuf[i] >> 18) & 0x3f) + 0x80);
373 *buf++ = CAST(unsigned char, ((ubuf[i] >> 12) & 0x3f) + 0x80);
374 *buf++ = CAST(unsigned char, ((ubuf[i] >> 6) & 0x3f) + 0x80);
375 *buf++ = CAST(unsigned char, (ubuf[i] & 0x3f) + 0x80);
376 } else if (ubuf[i] <= 0x7fffffff) {
379 *buf++ = CAST(unsigned char, (ubuf[i] >> 30) + 0xfc);
380 *buf++ = CAST(unsigned char, ((ubuf[i] >> 24) & 0x3f) + 0x80);
381 *buf++ = CAST(unsigned char, ((ubuf[i] >> 18) & 0x3f) + 0x80);
382 *buf++ = CAST(unsigned char, ((ubuf[i] >> 12) & 0x3f) + 0x80);
383 *buf++ = CAST(unsigned char, ((ubuf[i] >> 6) & 0x3f) + 0x80);
384 *buf++ = CAST(unsigned char, (ubuf[i] & 0x3f) + 0x80);
385 } else /* Invalid character */