1 /* $OpenBSD: process.c,v 1.35 2022/01/12 15:13:36 martijn Exp $ */
2
3 /*-
4 * Copyright (c) 1992 Diomidis Spinellis.
5 * Copyright (c) 1992, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Diomidis Spinellis of Imperial College, University of London.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <sys/types.h>
37 #include <sys/stat.h>
38 #include <sys/uio.h>
39
40 #include <ctype.h>
41 #include <errno.h>
42 #include <fcntl.h>
43 #include <limits.h>
44 #include <regex.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49
50 #include "defs.h"
51 #include "extern.h"
52
53 static SPACE HS, PS, SS;
54 #define pd PS.deleted
55 #define ps PS.space
56 #define psl PS.len
57 #define psanl PS.append_newline
58 #define hs HS.space
59 #define hsl HS.len
60
61 static inline int applies(struct s_command *);
62 static void flush_appends(void);
63 static void lputs(char *, size_t);
64 static inline int regexec_e(regex_t *, const char *, int, int, size_t,
65 size_t);
66 static void regsub(SPACE *, char *, char *);
67 static int substitute(struct s_command *);
68
69 struct s_appends *appends; /* Array of pointers to strings to append. */
70 static size_t appendx; /* Index into appends array. */
71 size_t appendnum; /* Size of appends array. */
72
73 static int lastaddr; /* Set by applies if last address of a range. */
74 static int sdone; /* If any substitutes since last line input. */
75 /* Iov structure for 'w' commands. */
76 static regex_t *defpreg;
77 size_t maxnsub;
78 regmatch_t *match;
79
80 #define OUT() do {\
81 fwrite(ps, 1, psl, outfile);\
82 if (psanl) fputc('\n', outfile);\
83 } while (0)
84
85 void
process(void)86 process(void)
87 {
88 struct s_command *cp;
89 SPACE tspace;
90 size_t len, oldpsl;
91 char *p;
92
93 for (linenum = 0; mf_fgets(&PS, REPLACE);) {
94 pd = 0;
95 top:
96 cp = prog;
97 redirect:
98 while (cp != NULL) {
99 if (!applies(cp)) {
100 cp = cp->next;
101 continue;
102 }
103 switch (cp->code) {
104 case '{':
105 cp = cp->u.c;
106 goto redirect;
107 case 'a':
108 if (appendx >= appendnum) {
109 appends = xreallocarray(appends,
110 appendnum,
111 2 * sizeof(struct s_appends));
112 appendnum *= 2;
113 }
114 appends[appendx].type = AP_STRING;
115 appends[appendx].s = cp->t;
116 appends[appendx].len = strlen(cp->t);
117 appendx++;
118 break;
119 case 'b':
120 cp = cp->u.c;
121 goto redirect;
122 case 'c':
123 pd = 1;
124 psl = 0;
125 if (cp->a2 == NULL || lastaddr || lastline())
126 (void)fprintf(outfile, "%s", cp->t);
127 break;
128 case 'd':
129 pd = 1;
130 goto new;
131 case 'D':
132 if (pd)
133 goto new;
134 if (psl == 0 ||
135 (p = memchr(ps, '\n', psl)) == NULL) {
136 pd = 1;
137 goto new;
138 } else {
139 psl -= (p + 1) - ps;
140 memmove(ps, p + 1, psl);
141 goto top;
142 }
143 case 'g':
144 cspace(&PS, hs, hsl, REPLACE);
145 break;
146 case 'G':
147 cspace(&PS, "\n", 1, 0);
148 cspace(&PS, hs, hsl, 0);
149 break;
150 case 'h':
151 cspace(&HS, ps, psl, REPLACE);
152 break;
153 case 'H':
154 cspace(&HS, "\n", 1, 0);
155 cspace(&HS, ps, psl, 0);
156 break;
157 case 'i':
158 (void)fprintf(outfile, "%s", cp->t);
159 break;
160 case 'l':
161 lputs(ps, psl);
162 break;
163 case 'n':
164 if (!nflag && !pd)
165 OUT();
166 flush_appends();
167 if (!mf_fgets(&PS, REPLACE))
168 exit(0);
169 pd = 0;
170 break;
171 case 'N':
172 flush_appends();
173 cspace(&PS, "\n", 1, 0);
174 if (!mf_fgets(&PS, 0))
175 exit(0);
176 break;
177 case 'p':
178 if (pd)
179 break;
180 OUT();
181 break;
182 case 'P':
183 if (pd)
184 break;
185 if ((p = memchr(ps, '\n', psl)) != NULL) {
186 oldpsl = psl;
187 psl = p - ps;
188 psanl = 1;
189 OUT();
190 psl = oldpsl;
191 } else {
192 OUT();
193 }
194 break;
195 case 'q':
196 if (!nflag && !pd)
197 OUT();
198 flush_appends();
199 finish_file();
200 exit(0);
201 case 'r':
202 if (appendx >= appendnum) {
203 appends = xreallocarray(appends,
204 appendnum,
205 2 * sizeof(struct s_appends));
206 appendnum *= 2;
207 }
208 appends[appendx].type = AP_FILE;
209 appends[appendx].s = cp->t;
210 appends[appendx].len = strlen(cp->t);
211 appendx++;
212 break;
213 case 's':
214 sdone |= substitute(cp);
215 break;
216 case 't':
217 if (sdone) {
218 sdone = 0;
219 cp = cp->u.c;
220 goto redirect;
221 }
222 break;
223 case 'w':
224 if (pd)
225 break;
226 if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
227 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
228 DEFFILEMODE)) == -1)
229 error(FATAL, "%s: %s",
230 cp->t, strerror(errno));
231 if ((size_t)write(cp->u.fd, ps, psl) != psl ||
232 write(cp->u.fd, "\n", 1) != 1)
233 error(FATAL, "%s: %s",
234 cp->t, strerror(errno));
235 break;
236 case 'x':
237 if (hs == NULL)
238 cspace(&HS, "", 0, REPLACE);
239 tspace = PS;
240 PS = HS;
241 psanl = tspace.append_newline;
242 HS = tspace;
243 break;
244 case 'y':
245 if (pd || psl == 0)
246 break;
247 for (p = ps, len = psl; len--; ++p)
248 *p = cp->u.y[(unsigned char)*p];
249 break;
250 case ':':
251 case '}':
252 break;
253 case '=':
254 (void)fprintf(outfile, "%lu\n", linenum);
255 }
256 cp = cp->next;
257 } /* for all cp */
258
259 new: if (!nflag && !pd)
260 OUT();
261 flush_appends();
262 } /* for all lines */
263 }
264
265 /*
266 * TRUE if the address passed matches the current program state
267 * (lastline, linenumber, ps).
268 */
269 #define MATCH(a) \
270 (a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, 0, psl) : \
271 (a)->type == AT_LINE ? linenum == (a)->u.l : lastline()
272
273 /*
274 * Return TRUE if the command applies to the current line. Sets the inrange
275 * flag to process ranges. Interprets the non-select (``!'') flag.
276 */
277 static inline int
applies(struct s_command * cp)278 applies(struct s_command *cp)
279 {
280 int r;
281
282 lastaddr = 0;
283 if (cp->a1 == NULL && cp->a2 == NULL)
284 r = 1;
285 else if (cp->a2)
286 if (cp->inrange) {
287 if (MATCH(cp->a2)) {
288 cp->inrange = 0;
289 lastaddr = 1;
290 }
291 r = 1;
292 } else if (MATCH(cp->a1)) {
293 /*
294 * If the second address is a number less than or
295 * equal to the line number first selected, only
296 * one line shall be selected.
297 * -- POSIX 1003.2
298 */
299 if (cp->a2->type == AT_LINE &&
300 linenum >= cp->a2->u.l)
301 lastaddr = 1;
302 else
303 cp->inrange = 1;
304 r = 1;
305 } else
306 r = 0;
307 else
308 r = MATCH(cp->a1);
309 return (cp->nonsel ? !r : r);
310 }
311
312 /*
313 * Reset all inrange markers.
314 */
315 void
resetstate(void)316 resetstate(void)
317 {
318 struct s_command *cp;
319
320 free(HS.back);
321 memset(&HS, 0, sizeof(HS));
322
323 for (cp = prog; cp; cp = cp->code == '{' ? cp->u.c : cp->next)
324 if (cp->a2)
325 cp->inrange = 0;
326 }
327
328 /*
329 * substitute --
330 * Do substitutions in the pattern space. Currently, we build a
331 * copy of the new pattern space in the substitute space structure
332 * and then swap them.
333 */
334 static int
substitute(struct s_command * cp)335 substitute(struct s_command *cp)
336 {
337 SPACE tspace;
338 regex_t *re;
339 regoff_t slen;
340 int n, lastempty;
341 regoff_t le = 0;
342 char *s;
343
344 s = ps;
345 re = cp->u.s->re;
346 if (re == NULL) {
347 if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
348 linenum = cp->u.s->linenum;
349 error(COMPILE, "\\%d not defined in the RE",
350 cp->u.s->maxbref);
351 }
352 }
353 if (!regexec_e(re, ps, 0, 0, 0, psl))
354 return (0);
355
356 SS.len = 0; /* Clean substitute space. */
357 slen = psl;
358 n = cp->u.s->n;
359 lastempty = 1;
360
361 do {
362 /* Copy the leading retained string. */
363 if (n <= 1 && (match[0].rm_so > le))
364 cspace(&SS, s, match[0].rm_so - le, APPEND);
365
366 /* Skip zero-length matches right after other matches. */
367 if (lastempty || (match[0].rm_so - le) ||
368 match[0].rm_so != match[0].rm_eo) {
369 if (n <= 1) {
370 /* Want this match: append replacement. */
371 regsub(&SS, ps, cp->u.s->new);
372 if (n == 1)
373 n = -1;
374 } else {
375 /* Want a later match: append original. */
376 if (match[0].rm_eo - le)
377 cspace(&SS, s, match[0].rm_eo - le,
378 APPEND);
379 n--;
380 }
381 }
382
383 /* Move past this match. */
384 s = ps + match[0].rm_eo;
385 slen = psl - match[0].rm_eo;
386 le = match[0].rm_eo;
387
388 /*
389 * After a zero-length match, advance one byte,
390 * and at the end of the line, terminate.
391 */
392 if (match[0].rm_so == match[0].rm_eo) {
393 if (*s == '\0' || *s == '\n')
394 slen = -1;
395 else
396 slen--;
397 if (*s != '\0') {
398 cspace(&SS, s++, 1, APPEND);
399 le++;
400 }
401 lastempty = 1;
402 } else
403 lastempty = 0;
404
405 } while (n >= 0 && slen >= 0 &&
406 regexec_e(re, ps, REG_NOTBOL, 0, le, psl));
407
408 /* Did not find the requested number of matches. */
409 if (n > 0)
410 return (0);
411
412 /* Copy the trailing retained string. */
413 if (slen > 0)
414 cspace(&SS, s, slen, APPEND);
415
416 /*
417 * Swap the substitute space and the pattern space, and make sure
418 * that any leftover pointers into stdio memory get lost.
419 */
420 tspace = PS;
421 PS = SS;
422 psanl = tspace.append_newline;
423 SS = tspace;
424 SS.space = SS.back;
425
426 /* Handle the 'p' flag. */
427 if (cp->u.s->p)
428 OUT();
429
430 /* Handle the 'w' flag. */
431 if (cp->u.s->wfile && !pd) {
432 if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
433 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
434 error(FATAL, "%s: %s", cp->u.s->wfile, strerror(errno));
435 if ((size_t)write(cp->u.s->wfd, ps, psl) != psl ||
436 write(cp->u.s->wfd, "\n", 1) != 1)
437 error(FATAL, "%s: %s", cp->u.s->wfile, strerror(errno));
438 }
439 return (1);
440 }
441
442 /*
443 * Flush append requests. Always called before reading a line,
444 * therefore it also resets the substitution done (sdone) flag.
445 */
446 static void
flush_appends(void)447 flush_appends(void)
448 {
449 FILE *f;
450 size_t count, idx;
451 char buf[8 * 1024];
452
453 for (idx = 0; idx < appendx; idx++)
454 switch (appends[idx].type) {
455 case AP_STRING:
456 fwrite(appends[idx].s, sizeof(char), appends[idx].len,
457 outfile);
458 break;
459 case AP_FILE:
460 /*
461 * Read files probably shouldn't be cached. Since
462 * it's not an error to read a non-existent file,
463 * it's possible that another program is interacting
464 * with the sed script through the file system. It
465 * would be truly bizarre, but possible. It's probably
466 * not that big a performance win, anyhow.
467 */
468 if ((f = fopen(appends[idx].s, "r")) == NULL)
469 break;
470 while ((count = fread(buf, sizeof(char), sizeof(buf), f)))
471 (void)fwrite(buf, sizeof(char), count, outfile);
472 (void)fclose(f);
473 break;
474 }
475 if (ferror(outfile))
476 error(FATAL, "%s: %s", outfname, strerror(errno ? errno : EIO));
477 appendx = sdone = 0;
478 }
479
480 static void
lputs(char * s,size_t len)481 lputs(char *s, size_t len)
482 {
483 int count;
484 extern int termwidth;
485 const char *escapes;
486 char *p;
487
488 for (count = 0; len > 0; len--, s++) {
489 if (count >= termwidth) {
490 (void)fprintf(outfile, "\\\n");
491 count = 0;
492 }
493 if (isascii((unsigned char)*s) && isprint((unsigned char)*s)
494 && *s != '\\') {
495 (void)fputc(*s, outfile);
496 count++;
497 } else if (*s == '\n') {
498 (void)fputc('$', outfile);
499 (void)fputc('\n', outfile);
500 count = 0;
501 } else {
502 escapes = "\\\a\b\f\r\t\v";
503 (void)fputc('\\', outfile);
504 if ((p = strchr(escapes, *s)) && *s != '\0') {
505 (void)fputc("\\abfrtv"[p - escapes], outfile);
506 count += 2;
507 } else {
508 (void)fprintf(outfile, "%03o", *(u_char *)s);
509 count += 4;
510 }
511 }
512 }
513 (void)fputc('$', outfile);
514 (void)fputc('\n', outfile);
515 if (ferror(outfile))
516 error(FATAL, "%s: %s", outfname, strerror(errno ? errno : EIO));
517 }
518
519 static inline int
regexec_e(regex_t * preg,const char * string,int eflags,int nomatch,size_t start,size_t stop)520 regexec_e(regex_t *preg, const char *string, int eflags,
521 int nomatch, size_t start, size_t stop)
522 {
523 int eval;
524
525 if (preg == NULL) {
526 if (defpreg == NULL)
527 error(FATAL, "first RE may not be empty");
528 } else
529 defpreg = preg;
530
531 /* Set anchors */
532 match[0].rm_so = start;
533 match[0].rm_eo = stop;
534
535 eval = regexec(defpreg, string,
536 nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
537 switch (eval) {
538 case 0:
539 return (1);
540 case REG_NOMATCH:
541 return (0);
542 }
543 error(FATAL, "RE error: %s", strregerror(eval, defpreg));
544 }
545
546 /*
547 * regsub - perform substitutions after a regexp match
548 * Based on a routine by Henry Spencer
549 */
550 static void
regsub(SPACE * sp,char * string,char * src)551 regsub(SPACE *sp, char *string, char *src)
552 {
553 int len, no;
554 char c, *dst;
555
556 #define NEEDSP(reqlen) \
557 if (sp->len + (reqlen) + 1 >= sp->blen) { \
558 size_t newlen = sp->blen + (reqlen) + 1024; \
559 sp->space = sp->back = xrealloc(sp->back, newlen); \
560 sp->blen = newlen; \
561 dst = sp->space + sp->len; \
562 }
563
564 dst = sp->space + sp->len;
565 while ((c = *src++) != '\0') {
566 if (c == '&')
567 no = 0;
568 else if (c == '\\' && isdigit((unsigned char)*src))
569 no = *src++ - '0';
570 else
571 no = -1;
572 if (no < 0) { /* Ordinary character. */
573 if (c == '\\' && (*src == '\\' || *src == '&'))
574 c = *src++;
575 NEEDSP(1);
576 *dst++ = c;
577 ++sp->len;
578 } else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
579 len = match[no].rm_eo - match[no].rm_so;
580 NEEDSP(len);
581 memmove(dst, string + match[no].rm_so, len);
582 dst += len;
583 sp->len += len;
584 }
585 }
586 NEEDSP(1);
587 *dst = '\0';
588 }
589
590 /*
591 * aspace --
592 * Append the source space to the destination space, allocating new
593 * space as necessary.
594 */
595 void
cspace(SPACE * sp,const char * p,size_t len,enum e_spflag spflag)596 cspace(SPACE *sp, const char *p, size_t len, enum e_spflag spflag)
597 {
598 size_t tlen;
599
600 /* Make sure SPACE has enough memory and ramp up quickly. */
601 tlen = sp->len + len + 1;
602 if (tlen > sp->blen) {
603 size_t newlen = tlen + 1024;
604 sp->space = sp->back = xrealloc(sp->back, newlen);
605 sp->blen = newlen;
606 }
607
608 if (spflag == REPLACE)
609 sp->len = 0;
610
611 memmove(sp->space + sp->len, p, len);
612
613 sp->space[sp->len += len] = '\0';
614 }
615
616 /*
617 * Close all cached opened files and report any errors
618 */
619 void
cfclose(struct s_command * cp,struct s_command * end)620 cfclose(struct s_command *cp, struct s_command *end)
621 {
622
623 for (; cp != end; cp = cp->next)
624 switch (cp->code) {
625 case 's':
626 if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
627 error(FATAL,
628 "%s: %s", cp->u.s->wfile, strerror(errno));
629 cp->u.s->wfd = -1;
630 break;
631 case 'w':
632 if (cp->u.fd != -1 && close(cp->u.fd))
633 error(FATAL, "%s: %s", cp->t, strerror(errno));
634 cp->u.fd = -1;
635 break;
636 case '{':
637 cfclose(cp->u.c, cp->next);
638 break;
639 }
640 }
641