parse.c revision 1.1.1.2 1 1.1 cgd /*
2 1.1.1.2 mrg * Copyright (c) 1989, 1993
3 1.1.1.2 mrg * The Regents of the University of California. All rights reserved.
4 1.1 cgd *
5 1.1 cgd * Redistribution and use in source and binary forms, with or without
6 1.1 cgd * modification, are permitted provided that the following conditions
7 1.1 cgd * are met:
8 1.1 cgd * 1. Redistributions of source code must retain the above copyright
9 1.1 cgd * notice, this list of conditions and the following disclaimer.
10 1.1 cgd * 2. Redistributions in binary form must reproduce the above copyright
11 1.1 cgd * notice, this list of conditions and the following disclaimer in the
12 1.1 cgd * documentation and/or other materials provided with the distribution.
13 1.1 cgd * 3. All advertising materials mentioning features or use of this software
14 1.1 cgd * must display the following acknowledgement:
15 1.1 cgd * This product includes software developed by the University of
16 1.1 cgd * California, Berkeley and its contributors.
17 1.1 cgd * 4. Neither the name of the University nor the names of its contributors
18 1.1 cgd * may be used to endorse or promote products derived from this software
19 1.1 cgd * without specific prior written permission.
20 1.1 cgd *
21 1.1 cgd * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 1.1 cgd * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 1.1 cgd * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 1.1 cgd * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 1.1 cgd * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 1.1 cgd * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 1.1 cgd * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 1.1 cgd * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 1.1 cgd * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 1.1 cgd * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 1.1 cgd * SUCH DAMAGE.
32 1.1 cgd */
33 1.1 cgd
34 1.1 cgd #ifndef lint
35 1.1.1.2 mrg static char sccsid[] = "@(#)parse.c 8.1 (Berkeley) 6/6/93";
36 1.1 cgd #endif /* not lint */
37 1.1 cgd
38 1.1 cgd #include <sys/types.h>
39 1.1.1.2 mrg
40 1.1.1.2 mrg #include <errno.h>
41 1.1.1.2 mrg #include <fcntl.h>
42 1.1 cgd #include <stdio.h>
43 1.1 cgd #include <stdlib.h>
44 1.1 cgd #include <ctype.h>
45 1.1 cgd #include <string.h>
46 1.1 cgd #include "hexdump.h"
47 1.1 cgd
48 1.1 cgd FU *endfu; /* format at end-of-data */
49 1.1 cgd
50 1.1.1.2 mrg void
51 1.1 cgd addfile(name)
52 1.1 cgd char *name;
53 1.1 cgd {
54 1.1 cgd register char *p;
55 1.1 cgd FILE *fp;
56 1.1 cgd int ch;
57 1.1 cgd char buf[2048 + 1];
58 1.1 cgd
59 1.1.1.2 mrg if ((fp = fopen(name, "r")) == NULL)
60 1.1.1.2 mrg err("%s: %s\n", name, strerror(errno));
61 1.1 cgd while (fgets(buf, sizeof(buf), fp)) {
62 1.1 cgd if (!(p = index(buf, '\n'))) {
63 1.1 cgd (void)fprintf(stderr, "hexdump: line too long.\n");
64 1.1 cgd while ((ch = getchar()) != '\n' && ch != EOF);
65 1.1 cgd continue;
66 1.1 cgd }
67 1.1 cgd *p = '\0';
68 1.1 cgd for (p = buf; *p && isspace(*p); ++p);
69 1.1 cgd if (!*p || *p == '#')
70 1.1 cgd continue;
71 1.1 cgd add(p);
72 1.1 cgd }
73 1.1 cgd (void)fclose(fp);
74 1.1 cgd }
75 1.1 cgd
76 1.1.1.2 mrg void
77 1.1 cgd add(fmt)
78 1.1 cgd char *fmt;
79 1.1 cgd {
80 1.1 cgd register char *p;
81 1.1 cgd static FS **nextfs;
82 1.1 cgd FS *tfs;
83 1.1 cgd FU *tfu, **nextfu;
84 1.1.1.2 mrg char *savep;
85 1.1 cgd
86 1.1 cgd /* start new linked list of format units */
87 1.1.1.2 mrg tfs = emalloc(sizeof(FS));
88 1.1 cgd if (!fshead)
89 1.1 cgd fshead = tfs;
90 1.1 cgd else
91 1.1 cgd *nextfs = tfs;
92 1.1 cgd nextfs = &tfs->nextfs;
93 1.1 cgd nextfu = &tfs->nextfu;
94 1.1 cgd
95 1.1 cgd /* take the format string and break it up into format units */
96 1.1 cgd for (p = fmt;;) {
97 1.1 cgd /* skip leading white space */
98 1.1 cgd for (; isspace(*p); ++p);
99 1.1 cgd if (!*p)
100 1.1 cgd break;
101 1.1 cgd
102 1.1 cgd /* allocate a new format unit and link it in */
103 1.1.1.2 mrg tfu = emalloc(sizeof(FU));
104 1.1 cgd *nextfu = tfu;
105 1.1 cgd nextfu = &tfu->nextfu;
106 1.1 cgd tfu->reps = 1;
107 1.1 cgd
108 1.1 cgd /* if leading digit, repetition count */
109 1.1 cgd if (isdigit(*p)) {
110 1.1 cgd for (savep = p; isdigit(*p); ++p);
111 1.1 cgd if (!isspace(*p) && *p != '/')
112 1.1 cgd badfmt(fmt);
113 1.1 cgd /* may overwrite either white space or slash */
114 1.1 cgd tfu->reps = atoi(savep);
115 1.1 cgd tfu->flags = F_SETREP;
116 1.1 cgd /* skip trailing white space */
117 1.1 cgd for (++p; isspace(*p); ++p);
118 1.1 cgd }
119 1.1 cgd
120 1.1 cgd /* skip slash and trailing white space */
121 1.1 cgd if (*p == '/')
122 1.1 cgd while (isspace(*++p));
123 1.1 cgd
124 1.1 cgd /* byte count */
125 1.1 cgd if (isdigit(*p)) {
126 1.1 cgd for (savep = p; isdigit(*p); ++p);
127 1.1 cgd if (!isspace(*p))
128 1.1 cgd badfmt(fmt);
129 1.1 cgd tfu->bcnt = atoi(savep);
130 1.1 cgd /* skip trailing white space */
131 1.1 cgd for (++p; isspace(*p); ++p);
132 1.1 cgd }
133 1.1 cgd
134 1.1 cgd /* format */
135 1.1 cgd if (*p != '"')
136 1.1 cgd badfmt(fmt);
137 1.1 cgd for (savep = ++p; *p != '"';)
138 1.1 cgd if (*p++ == 0)
139 1.1 cgd badfmt(fmt);
140 1.1 cgd if (!(tfu->fmt = malloc(p - savep + 1)))
141 1.1 cgd nomem();
142 1.1 cgd (void) strncpy(tfu->fmt, savep, p - savep);
143 1.1 cgd tfu->fmt[p - savep] = '\0';
144 1.1 cgd escape(tfu->fmt);
145 1.1 cgd p++;
146 1.1 cgd }
147 1.1 cgd }
148 1.1 cgd
149 1.1 cgd static char *spec = ".#-+ 0123456789";
150 1.1.1.2 mrg
151 1.1.1.2 mrg int
152 1.1 cgd size(fs)
153 1.1 cgd FS *fs;
154 1.1 cgd {
155 1.1 cgd register FU *fu;
156 1.1 cgd register int bcnt, cursize;
157 1.1 cgd register char *fmt;
158 1.1 cgd int prec;
159 1.1 cgd
160 1.1 cgd /* figure out the data block size needed for each format unit */
161 1.1 cgd for (cursize = 0, fu = fs->nextfu; fu; fu = fu->nextfu) {
162 1.1 cgd if (fu->bcnt) {
163 1.1 cgd cursize += fu->bcnt * fu->reps;
164 1.1 cgd continue;
165 1.1 cgd }
166 1.1 cgd for (bcnt = prec = 0, fmt = fu->fmt; *fmt; ++fmt) {
167 1.1 cgd if (*fmt != '%')
168 1.1 cgd continue;
169 1.1 cgd /*
170 1.1 cgd * skip any special chars -- save precision in
171 1.1 cgd * case it's a %s format.
172 1.1 cgd */
173 1.1 cgd while (index(spec + 1, *++fmt));
174 1.1 cgd if (*fmt == '.' && isdigit(*++fmt)) {
175 1.1 cgd prec = atoi(fmt);
176 1.1 cgd while (isdigit(*++fmt));
177 1.1 cgd }
178 1.1 cgd switch(*fmt) {
179 1.1 cgd case 'c':
180 1.1 cgd bcnt += 1;
181 1.1 cgd break;
182 1.1 cgd case 'd': case 'i': case 'o': case 'u':
183 1.1 cgd case 'x': case 'X':
184 1.1 cgd bcnt += 4;
185 1.1 cgd break;
186 1.1 cgd case 'e': case 'E': case 'f': case 'g': case 'G':
187 1.1 cgd bcnt += 8;
188 1.1 cgd break;
189 1.1 cgd case 's':
190 1.1 cgd bcnt += prec;
191 1.1 cgd break;
192 1.1 cgd case '_':
193 1.1 cgd switch(*++fmt) {
194 1.1 cgd case 'c': case 'p': case 'u':
195 1.1 cgd bcnt += 1;
196 1.1 cgd break;
197 1.1 cgd }
198 1.1 cgd }
199 1.1 cgd }
200 1.1 cgd cursize += bcnt * fu->reps;
201 1.1 cgd }
202 1.1.1.2 mrg return (cursize);
203 1.1 cgd }
204 1.1 cgd
205 1.1.1.2 mrg void
206 1.1 cgd rewrite(fs)
207 1.1 cgd FS *fs;
208 1.1 cgd {
209 1.1 cgd enum { NOTOKAY, USEBCNT, USEPREC } sokay;
210 1.1 cgd register PR *pr, **nextpr;
211 1.1 cgd register FU *fu;
212 1.1 cgd register char *p1, *p2;
213 1.1.1.2 mrg char savech, *fmtp, cs[3];
214 1.1 cgd int nconv, prec;
215 1.1 cgd
216 1.1 cgd for (fu = fs->nextfu; fu; fu = fu->nextfu) {
217 1.1 cgd /*
218 1.1.1.2 mrg * Break each format unit into print units; each conversion
219 1.1.1.2 mrg * character gets its own.
220 1.1 cgd */
221 1.1 cgd for (nconv = 0, fmtp = fu->fmt; *fmtp; nextpr = &pr->nextpr) {
222 1.1.1.2 mrg pr = emalloc(sizeof(PR));
223 1.1 cgd if (!fu->nextpr)
224 1.1 cgd fu->nextpr = pr;
225 1.1 cgd else
226 1.1 cgd *nextpr = pr;
227 1.1 cgd
228 1.1.1.2 mrg /* Skip preceding text and up to the next % sign. */
229 1.1 cgd for (p1 = fmtp; *p1 && *p1 != '%'; ++p1);
230 1.1 cgd
231 1.1.1.2 mrg /* Only text in the string. */
232 1.1 cgd if (!*p1) {
233 1.1 cgd pr->fmt = fmtp;
234 1.1 cgd pr->flags = F_TEXT;
235 1.1 cgd break;
236 1.1 cgd }
237 1.1 cgd
238 1.1 cgd /*
239 1.1.1.2 mrg * Get precision for %s -- if have a byte count, don't
240 1.1 cgd * need it.
241 1.1 cgd */
242 1.1 cgd if (fu->bcnt) {
243 1.1 cgd sokay = USEBCNT;
244 1.1.1.2 mrg /* Skip to conversion character. */
245 1.1 cgd for (++p1; index(spec, *p1); ++p1);
246 1.1 cgd } else {
247 1.1.1.2 mrg /* Skip any special chars, field width. */
248 1.1 cgd while (index(spec + 1, *++p1));
249 1.1 cgd if (*p1 == '.' && isdigit(*++p1)) {
250 1.1 cgd sokay = USEPREC;
251 1.1 cgd prec = atoi(p1);
252 1.1 cgd while (isdigit(*++p1));
253 1.1.1.2 mrg } else
254 1.1 cgd sokay = NOTOKAY;
255 1.1 cgd }
256 1.1 cgd
257 1.1.1.2 mrg p2 = p1 + 1; /* Set end pointer. */
258 1.1.1.2 mrg cs[0] = *p1; /* Set conversion string. */
259 1.1.1.2 mrg cs[1] = '\0';
260 1.1 cgd
261 1.1 cgd /*
262 1.1.1.2 mrg * Figure out the byte count for each conversion;
263 1.1 cgd * rewrite the format as necessary, set up blank-
264 1.1 cgd * padding for end of data.
265 1.1 cgd */
266 1.1.1.2 mrg switch(cs[0]) {
267 1.1 cgd case 'c':
268 1.1 cgd pr->flags = F_CHAR;
269 1.1 cgd switch(fu->bcnt) {
270 1.1 cgd case 0: case 1:
271 1.1 cgd pr->bcnt = 1;
272 1.1 cgd break;
273 1.1 cgd default:
274 1.1 cgd p1[1] = '\0';
275 1.1 cgd badcnt(p1);
276 1.1 cgd }
277 1.1 cgd break;
278 1.1 cgd case 'd': case 'i':
279 1.1 cgd pr->flags = F_INT;
280 1.1.1.2 mrg goto isint;
281 1.1 cgd case 'o': case 'u': case 'x': case 'X':
282 1.1 cgd pr->flags = F_UINT;
283 1.1.1.2 mrg isint: cs[2] = '\0';
284 1.1.1.2 mrg cs[1] = cs[0];
285 1.1.1.2 mrg cs[0] = 'q';
286 1.1.1.2 mrg switch(fu->bcnt) {
287 1.1 cgd case 0: case 4:
288 1.1 cgd pr->bcnt = 4;
289 1.1 cgd break;
290 1.1 cgd case 1:
291 1.1 cgd pr->bcnt = 1;
292 1.1 cgd break;
293 1.1 cgd case 2:
294 1.1 cgd pr->bcnt = 2;
295 1.1 cgd break;
296 1.1 cgd default:
297 1.1 cgd p1[1] = '\0';
298 1.1 cgd badcnt(p1);
299 1.1 cgd }
300 1.1 cgd break;
301 1.1 cgd case 'e': case 'E': case 'f': case 'g': case 'G':
302 1.1 cgd pr->flags = F_DBL;
303 1.1 cgd switch(fu->bcnt) {
304 1.1 cgd case 0: case 8:
305 1.1 cgd pr->bcnt = 8;
306 1.1 cgd break;
307 1.1 cgd case 4:
308 1.1 cgd pr->bcnt = 4;
309 1.1 cgd break;
310 1.1 cgd default:
311 1.1 cgd p1[1] = '\0';
312 1.1 cgd badcnt(p1);
313 1.1 cgd }
314 1.1 cgd break;
315 1.1 cgd case 's':
316 1.1 cgd pr->flags = F_STR;
317 1.1 cgd switch(sokay) {
318 1.1 cgd case NOTOKAY:
319 1.1 cgd badsfmt();
320 1.1 cgd case USEBCNT:
321 1.1 cgd pr->bcnt = fu->bcnt;
322 1.1 cgd break;
323 1.1 cgd case USEPREC:
324 1.1 cgd pr->bcnt = prec;
325 1.1 cgd break;
326 1.1 cgd }
327 1.1 cgd break;
328 1.1 cgd case '_':
329 1.1 cgd ++p2;
330 1.1 cgd switch(p1[1]) {
331 1.1 cgd case 'A':
332 1.1 cgd endfu = fu;
333 1.1 cgd fu->flags |= F_IGNORE;
334 1.1 cgd /* FALLTHROUGH */
335 1.1 cgd case 'a':
336 1.1 cgd pr->flags = F_ADDRESS;
337 1.1 cgd ++p2;
338 1.1 cgd switch(p1[2]) {
339 1.1 cgd case 'd': case 'o': case'x':
340 1.1.1.2 mrg cs[0] = 'q';
341 1.1.1.2 mrg cs[1] = p1[2];
342 1.1.1.2 mrg cs[2] = '\0';
343 1.1 cgd break;
344 1.1 cgd default:
345 1.1 cgd p1[3] = '\0';
346 1.1 cgd badconv(p1);
347 1.1 cgd }
348 1.1 cgd break;
349 1.1 cgd case 'c':
350 1.1 cgd pr->flags = F_C;
351 1.1.1.2 mrg /* cs[0] = 'c'; set in conv_c */
352 1.1.1.2 mrg goto isint2;
353 1.1 cgd case 'p':
354 1.1 cgd pr->flags = F_P;
355 1.1.1.2 mrg cs[0] = 'c';
356 1.1.1.2 mrg goto isint2;
357 1.1 cgd case 'u':
358 1.1 cgd pr->flags = F_U;
359 1.1.1.2 mrg /* cs[0] = 'c'; set in conv_u */
360 1.1.1.2 mrg isint2: switch(fu->bcnt) {
361 1.1 cgd case 0: case 1:
362 1.1 cgd pr->bcnt = 1;
363 1.1 cgd break;
364 1.1 cgd default:
365 1.1 cgd p1[2] = '\0';
366 1.1 cgd badcnt(p1);
367 1.1 cgd }
368 1.1 cgd break;
369 1.1 cgd default:
370 1.1 cgd p1[2] = '\0';
371 1.1 cgd badconv(p1);
372 1.1 cgd }
373 1.1 cgd break;
374 1.1 cgd default:
375 1.1 cgd p1[1] = '\0';
376 1.1 cgd badconv(p1);
377 1.1 cgd }
378 1.1 cgd
379 1.1 cgd /*
380 1.1.1.2 mrg * Copy to PR format string, set conversion character
381 1.1 cgd * pointer, update original.
382 1.1 cgd */
383 1.1 cgd savech = *p2;
384 1.1.1.2 mrg p1[0] = '\0';
385 1.1.1.2 mrg pr->fmt = emalloc(strlen(fmtp) + 2);
386 1.1.1.2 mrg (void)strcpy(pr->fmt, fmtp);
387 1.1.1.2 mrg (void)strcat(pr->fmt, cs);
388 1.1 cgd *p2 = savech;
389 1.1 cgd pr->cchar = pr->fmt + (p1 - fmtp);
390 1.1 cgd fmtp = p2;
391 1.1 cgd
392 1.1.1.2 mrg /* Only one conversion character if byte count. */
393 1.1.1.2 mrg if (!(pr->flags&F_ADDRESS) && fu->bcnt && nconv++)
394 1.1.1.2 mrg err("byte count with multiple conversion characters");
395 1.1 cgd }
396 1.1 cgd /*
397 1.1.1.2 mrg * If format unit byte count not specified, figure it out
398 1.1 cgd * so can adjust rep count later.
399 1.1 cgd */
400 1.1 cgd if (!fu->bcnt)
401 1.1 cgd for (pr = fu->nextpr; pr; pr = pr->nextpr)
402 1.1 cgd fu->bcnt += pr->bcnt;
403 1.1 cgd }
404 1.1 cgd /*
405 1.1.1.2 mrg * If the format string interprets any data at all, and it's
406 1.1 cgd * not the same as the blocksize, and its last format unit
407 1.1 cgd * interprets any data at all, and has no iteration count,
408 1.1 cgd * repeat it as necessary.
409 1.1 cgd *
410 1.1.1.2 mrg * If, rep count is greater than 1, no trailing whitespace
411 1.1 cgd * gets output from the last iteration of the format unit.
412 1.1 cgd */
413 1.1 cgd for (fu = fs->nextfu;; fu = fu->nextfu) {
414 1.1 cgd if (!fu->nextfu && fs->bcnt < blocksize &&
415 1.1 cgd !(fu->flags&F_SETREP) && fu->bcnt)
416 1.1 cgd fu->reps += (blocksize - fs->bcnt) / fu->bcnt;
417 1.1 cgd if (fu->reps > 1) {
418 1.1 cgd for (pr = fu->nextpr;; pr = pr->nextpr)
419 1.1 cgd if (!pr->nextpr)
420 1.1 cgd break;
421 1.1 cgd for (p1 = pr->fmt, p2 = NULL; *p1; ++p1)
422 1.1 cgd p2 = isspace(*p1) ? p1 : NULL;
423 1.1 cgd if (p2)
424 1.1 cgd pr->nospace = p2;
425 1.1 cgd }
426 1.1 cgd if (!fu->nextfu)
427 1.1 cgd break;
428 1.1 cgd }
429 1.1.1.2 mrg #ifdef DEBUG
430 1.1.1.2 mrg for (fu = fs->nextfu; fu; fu = fu->nextfu) {
431 1.1.1.2 mrg (void)printf("fmt:");
432 1.1.1.2 mrg for (pr = fu->nextpr; pr; pr = pr->nextpr)
433 1.1.1.2 mrg (void)printf(" {%s}", pr->fmt);
434 1.1.1.2 mrg (void)printf("\n");
435 1.1.1.2 mrg }
436 1.1.1.2 mrg #endif
437 1.1 cgd }
438 1.1 cgd
439 1.1.1.2 mrg void
440 1.1 cgd escape(p1)
441 1.1 cgd register char *p1;
442 1.1 cgd {
443 1.1 cgd register char *p2;
444 1.1 cgd
445 1.1 cgd /* alphabetic escape sequences have to be done in place */
446 1.1 cgd for (p2 = p1;; ++p1, ++p2) {
447 1.1 cgd if (!*p1) {
448 1.1 cgd *p2 = *p1;
449 1.1 cgd break;
450 1.1 cgd }
451 1.1 cgd if (*p1 == '\\')
452 1.1 cgd switch(*++p1) {
453 1.1 cgd case 'a':
454 1.1 cgd /* *p2 = '\a'; */
455 1.1 cgd *p2 = '\007';
456 1.1 cgd break;
457 1.1 cgd case 'b':
458 1.1 cgd *p2 = '\b';
459 1.1 cgd break;
460 1.1 cgd case 'f':
461 1.1 cgd *p2 = '\f';
462 1.1 cgd break;
463 1.1 cgd case 'n':
464 1.1 cgd *p2 = '\n';
465 1.1 cgd break;
466 1.1 cgd case 'r':
467 1.1 cgd *p2 = '\r';
468 1.1 cgd break;
469 1.1 cgd case 't':
470 1.1 cgd *p2 = '\t';
471 1.1 cgd break;
472 1.1 cgd case 'v':
473 1.1 cgd *p2 = '\v';
474 1.1 cgd break;
475 1.1 cgd default:
476 1.1 cgd *p2 = *p1;
477 1.1 cgd break;
478 1.1 cgd }
479 1.1 cgd }
480 1.1 cgd }
481 1.1 cgd
482 1.1.1.2 mrg void
483 1.1 cgd badcnt(s)
484 1.1 cgd char *s;
485 1.1 cgd {
486 1.1.1.2 mrg err("%s: bad byte count", s);
487 1.1 cgd }
488 1.1 cgd
489 1.1.1.2 mrg void
490 1.1 cgd badsfmt()
491 1.1 cgd {
492 1.1.1.2 mrg err("%%s: requires a precision or a byte count\n");
493 1.1 cgd }
494 1.1 cgd
495 1.1.1.2 mrg void
496 1.1 cgd badfmt(fmt)
497 1.1 cgd char *fmt;
498 1.1 cgd {
499 1.1.1.2 mrg err("\"%s\": bad format\n", fmt);
500 1.1 cgd }
501 1.1 cgd
502 1.1.1.2 mrg void
503 1.1 cgd badconv(ch)
504 1.1 cgd char *ch;
505 1.1 cgd {
506 1.1.1.2 mrg err("%%%s: bad conversion character\n", ch);
507 1.1 cgd }
508