xref: /netbsd-src/bin/sh/histedit.c (revision ccd9df534e375a4366c5b55f23782053c7a98d82)
1 /*	$NetBSD: histedit.c,v 1.69 2024/07/05 04:07:26 kre Exp $	*/
2 
3 /*-
4  * Copyright (c) 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Kenneth Almquist.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)histedit.c	8.2 (Berkeley) 5/4/95";
39 #else
40 __RCSID("$NetBSD: histedit.c,v 1.69 2024/07/05 04:07:26 kre Exp $");
41 #endif
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 #include <sys/stat.h>
46 #include <dirent.h>
47 #include <paths.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <unistd.h>
51 /*
52  * Editline and history functions (and glue).
53  */
54 #include "shell.h"
55 #include "parser.h"
56 #include "var.h"
57 #include "options.h"
58 #include "builtins.h"
59 #include "main.h"
60 #include "output.h"
61 #include "mystring.h"
62 #include "myhistedit.h"
63 #include "error.h"
64 #include "alias.h"
65 
66 #ifndef SMALL		/* almost all the rest of this file */
67 
68 #include "eval.h"
69 #include "memalloc.h"
70 #include "show.h"
71 
72 #define MAXHISTLOOPS	4	/* max recursions through fc */
73 #define DEFEDITOR	"ed"	/* default editor *should* be $EDITOR */
74 
75 History *hist;	/* history cookie */
76 EditLine *el;	/* editline cookie */
77 int displayhist;
78 static FILE *el_in, *el_out;
79 static int curpos;
80 
81 #ifdef DEBUG
82 extern FILE *tracefile;
83 #endif
84 
85 static const char *fc_replace(const char *, char *, char *);
86 static int not_fcnumber(const char *);
87 static int str_to_event(const char *, int);
88 static int comparator(const void *, const void *);
89 static char **sh_matches(const char *, int, int);
90 static unsigned char sh_complete(EditLine *, int);
91 
92 /*
93  * Set history and editing status.  Called whenever the status may
94  * have changed (figures out what to do).
95  */
96 void
97 histedit(void)
98 {
99 	FILE *el_err;
100 
101 #define editing (Eflag || Vflag)
102 
103 	CTRACE(DBG_HISTORY, ("histedit: %cE%cV %sinteractive\n",
104 	    Eflag ? '-' : '+',  Vflag ? '-' : '+', iflag ? "" : "not "));
105 
106 	if (iflag == 1) {
107 		if (!hist) {
108 			/*
109 			 * turn history on
110 			 */
111 			INTOFF;
112 			hist = history_init();
113 			INTON;
114 
115 			if (hist != NULL)
116 				sethistsize(histsizeval());
117 			else
118 				out2str("sh: can't initialize history\n");
119 		}
120 		if (editing && !el && isatty(0)) { /* && isatty(2) ??? */
121 			/*
122 			 * turn editing on
123 			 */
124 			char *term;
125 
126 			INTOFF;
127 			if (el_in == NULL)
128 				el_in = fdopen(0, "r");
129 			if (el_out == NULL)
130 				el_out = fdopen(2, "w");
131 			if (el_in == NULL || el_out == NULL)
132 				goto bad;
133 			el_err = el_out;
134 #if DEBUG
135 			if (tracefile)
136 				el_err = tracefile;
137 #endif
138 			/*
139 			 * This odd piece of code doesn't affect the shell
140 			 * at all, the environment modified here is the
141 			 * stuff accessed via "environ" (the incoming
142 			 * environment to the shell) which is only ever
143 			 * touched at sh startup time (long before we get
144 			 * here) and ignored thereafter.
145 			 *
146 			 * But libedit calls getenv() to discover TERM
147 			 * and that searches the "environ" environment,
148 			 * not the shell's internal variable data struct,
149 			 * so we need to make sure that TERM in there is
150 			 * correct.
151 			 *
152 			 * This sequence copies TERM from the shell into
153 			 * the old "environ" environment.
154 			 */
155 			term = lookupvar("TERM");
156 			if (term)
157 				setenv("TERM", term, 1);
158 			else
159 				unsetenv("TERM");
160 			el = el_init("sh", el_in, el_out, el_err);
161 			VTRACE(DBG_HISTORY, ("el_init() %sed\n",
162 			    el != NULL ? "succeed" : "fail"));
163 			if (el != NULL) {
164 				if (hist)
165 					el_set(el, EL_HIST, history, hist);
166 
167 				set_prompt_lit(lookupvar("PSlit"));
168 				el_set(el, EL_SIGNAL, 1);
169 				el_set(el, EL_SAFEREAD, 1);
170 				el_set(el, EL_ALIAS_TEXT, alias_text, NULL);
171 				el_set(el, EL_ADDFN, "rl-complete",
172 				    "ReadLine compatible completion function",
173 				    sh_complete);
174 			} else {
175  bad:;
176 				out2str("sh: can't initialize editing\n");
177 			}
178 			INTON;
179 		} else if (!editing && el) {
180 			INTOFF;
181 			el_end(el);
182 			el = NULL;
183 			VTRACE(DBG_HISTORY, ("line editing disabled\n"));
184 			INTON;
185 		}
186 		if (el) {
187 			INTOFF;
188 			if (Vflag)
189 				el_set(el, EL_EDITOR, "vi");
190 			else if (Eflag)
191 				el_set(el, EL_EDITOR, "emacs");
192 			VTRACE(DBG_HISTORY, ("reading $EDITRC\n"));
193 			el_source(el, lookupvar("EDITRC"));
194 			el_set(el, EL_BIND, "^I",
195 			    tabcomplete ? "rl-complete" : "ed-insert", NULL);
196 			INTON;
197 		}
198 	} else {
199 		INTOFF;
200 		if (el) {	/* no editing if not interactive */
201 			el_end(el);
202 			el = NULL;
203 		}
204 		if (hist) {
205 			history_end(hist);
206 			hist = NULL;
207 		}
208 		INTON;
209 		VTRACE(DBG_HISTORY, ("line editing & history disabled\n"));
210 	}
211 }
212 
213 void
214 set_prompt_lit(const char *lit_ch)
215 {
216 	wchar_t wc;
217 
218 	if (!(iflag && editing && el))
219 		return;
220 
221 	if (lit_ch == NULL) {
222 		el_set(el, EL_PROMPT, getprompt);
223 		return;
224 	}
225 
226 	mbtowc(&wc, NULL, 1);		/* state init */
227 
228 	INTOFF;
229 	if (mbtowc(&wc, lit_ch, strlen(lit_ch)) <= 0)
230 		el_set(el, EL_PROMPT, getprompt);
231 	else
232 		el_set(el, EL_PROMPT_ESC, getprompt, (int)wc);
233 	INTON;
234 }
235 
236 void
237 set_editrc(const char *fname)
238 {
239 	INTOFF;
240 	if (iflag && editing && el)
241 		el_source(el, fname);
242 	INTON;
243 }
244 
245 void
246 sethistsize(const char *hs)
247 {
248 	int histsize;
249 	HistEvent he;
250 
251 	if (hist != NULL) {
252 		if (hs == NULL || *hs == '\0' || !is_number(hs) ||
253 		   (histsize = number(hs)) < 0)
254 			histsize = 100;
255 		INTOFF;
256 		history(hist, &he, H_SETSIZE, histsize);
257 		history(hist, &he, H_SETUNIQUE, 1);
258 		INTON;
259 	}
260 }
261 
262 void
263 setterm(const char *term)
264 {
265 	INTOFF;
266 	if (el != NULL && term != NULL)
267 		if (el_set(el, EL_TERMINAL, term) != 0) {
268 			outfmt(out2, "sh: Can't set terminal type %s\n", term);
269 			outfmt(out2, "sh: Using dumb terminal settings.\n");
270 		}
271 	INTON;
272 }
273 
274 int
275 inputrc(int argc, char **argv)
276 {
277 	CTRACE(DBG_HISTORY, ("inputrc (%d arg%s)", argc-1, argc==2?"":"s"));
278 	if (argc != 2) {
279 		CTRACE(DBG_HISTORY, (" -- bad\n"));
280 		out2str("usage: inputrc file\n");
281 		return 1;
282 	}
283 	CTRACE(DBG_HISTORY, (" file: \"%s\"\n", argv[1]));
284 	if (el != NULL) {
285 		INTOFF;
286 		if (el_source(el, argv[1])) {
287 			INTON;
288 			out2str("inputrc: failed\n");
289 			return 1;
290 		}
291 		INTON;
292 		return 0;
293 	} else {
294 		out2str("sh: inputrc ignored, not editing\n");
295 		return 1;
296 	}
297 }
298 
299 /*
300  *  This command is provided since POSIX decided to standardize
301  *  the Korn shell fc command.  Oh well...
302  */
303 int
304 histcmd(volatile int argc, char ** volatile argv)
305 {
306 	int ch;
307 	const char * volatile editor = NULL;
308 	HistEvent he;
309 	volatile int lflg = 0, nflg = 0, rflg = 0, sflg = 0;
310 	int i, retval;
311 	const char *firststr, *laststr;
312 	int first, last, direction;
313 
314 	char * volatile pat = NULL;	/* ksh "fc old=new" crap */
315 	char * volatile repl;
316 
317 	static int active = 0;
318 	struct jmploc jmploc;
319 	struct jmploc *volatile savehandler;
320 	char editfile[MAXPATHLEN + 1];
321 	FILE * volatile efp;
322 
323 #ifdef __GNUC__
324 	repl = NULL;	/* XXX gcc4 */
325 	efp = NULL;	/* XXX gcc4 */
326 #endif
327 
328 	if (hist == NULL)
329 		error("history not active");
330 
331 	CTRACE(DBG_HISTORY, ("histcmd (fc) %d arg%s\n", argc, argc==1?"":"s"));
332 	if (argc == 1)
333 		error("missing history argument");
334 
335 	optreset = 1; optind = 1; /* initialize getopt */
336 	while (not_fcnumber(argv[optind]) &&
337 	      (ch = getopt(argc, argv, ":e:lnrs")) != -1)
338 		switch ((char)ch) {
339 		case 'e':
340 			editor = optarg;
341 			VTRACE(DBG_HISTORY, ("histcmd -e %s\n", editor));
342 			break;
343 		case 'l':
344 			lflg = 1;
345 			VTRACE(DBG_HISTORY, ("histcmd -l\n"));
346 			break;
347 		case 'n':
348 			nflg = 1;
349 			VTRACE(DBG_HISTORY, ("histcmd -n\n"));
350 			break;
351 		case 'r':
352 			rflg = 1;
353 			VTRACE(DBG_HISTORY, ("histcmd -r\n"));
354 			break;
355 		case 's':
356 			sflg = 1;
357 			VTRACE(DBG_HISTORY, ("histcmd -s\n"));
358 			break;
359 		case ':':
360 			error("option -%c expects argument", optopt);
361 			/* NOTREACHED */
362 		case '?':
363 		default:
364 			error("unknown option: -%c", optopt);
365 			/* NOTREACHED */
366 		}
367 	argc -= optind, argv += optind;
368 
369 	/*
370 	 * If executing...
371 	 */
372 	if (lflg == 0 || editor || sflg) {
373 		lflg = 0;	/* ignore */
374 		editfile[0] = '\0';
375 		/*
376 		 * Catch interrupts to reset active counter and
377 		 * cleanup temp files.
378 		 */
379 		savehandler = handler;
380 		if (setjmp(jmploc.loc)) {
381 			active = 0;
382 			if (*editfile) {
383 				VTRACE(DBG_HISTORY,
384 				    ("histcmd err jump unlink temp \"%s\"\n",
385 				    editfile));
386 				unlink(editfile);
387 			}
388 			handler = savehandler;
389 			longjmp(handler->loc, 1);
390 		}
391 		handler = &jmploc;
392 		VTRACE(DBG_HISTORY, ("histcmd is active %d(++)\n", active));
393 		if (++active > MAXHISTLOOPS) {
394 			active = 0;
395 			displayhist = 0;
396 			error("called recursively too many times");
397 		}
398 		/*
399 		 * Set editor.
400 		 */
401 		if (sflg == 0) {
402 			if (editor == NULL &&
403 			    (editor = bltinlookup("FCEDIT", 1)) == NULL &&
404 			    (editor = bltinlookup("EDITOR", 1)) == NULL)
405 				editor = DEFEDITOR;
406 			if (editor[0] == '-' && editor[1] == '\0') {
407 				sflg = 1;	/* no edit */
408 				editor = NULL;
409 			}
410 			VTRACE(DBG_HISTORY, ("histcmd using %s as editor\n",
411 			    editor == NULL ? "-nothing-" : editor));
412 		}
413 	}
414 
415 	/*
416 	 * If executing, parse [old=new] now
417 	 */
418 	if (lflg == 0 && argc > 0 &&
419 	     ((repl = strchr(argv[0], '=')) != NULL)) {
420 		pat = argv[0];
421 		*repl++ = '\0';
422 		argc--, argv++;
423 		VTRACE(DBG_HISTORY, ("histcmd replace old=\"%s\" new=\"%s\""
424 		    " (%d args)\n", pat, repl, argc));
425 	}
426 
427 	/*
428 	 * If -s is specified, accept only one operand
429 	 */
430 	if (sflg && argc >= 2)
431 		error("too many args");
432 
433 	/*
434 	 * determine [first] and [last]
435 	 */
436 	switch (argc) {
437 	case 0:
438 		if (lflg) {
439 			firststr = "-16";
440 			laststr = "-1";
441 		} else
442 			firststr = laststr = "-1";
443 		break;
444 	case 1:
445 		firststr = argv[0];
446 		laststr = lflg ? "-1" : argv[0];
447 		break;
448 	case 2:
449 		firststr = argv[0];
450 		laststr = argv[1];
451 		break;
452 	default:
453 		error("too many args");
454 		/* NOTREACHED */
455 	}
456 	/*
457 	 * Turn into event numbers.
458 	 */
459 	first = str_to_event(firststr, 0);
460 	last = str_to_event(laststr, 1);
461 
462 	if (first == -1 || last == -1) {
463 		if (lflg)   /* no history exists, that's OK */
464 			return 0;
465 		if (first == -1 && last == -1) {
466 			if (firststr != laststr)
467 				error("history events %s to %s do not exist",
468 				    firststr, laststr);
469 			else
470 				error("history event %s does not exist",
471 				    firststr);
472 		} else {
473 			error("history event %s does not exist",
474 			    first == -1 ? firststr : laststr);
475 		}
476 	}
477 
478 	if (rflg) {
479 		i = last;
480 		last = first;
481 		first = i;
482 	}
483 	VTRACE(DBG_HISTORY, ("histcmd%s first=\"%s\" (#%d) last=\"%s\" (#%d)\n",
484 	    rflg ? " reversed" : "", rflg ? laststr : firststr, first,
485 	    rflg ? firststr : laststr, last));
486 
487 	/*
488 	 * XXX - this should not depend on the event numbers
489 	 * always increasing.  Add sequence numbers or offset
490 	 * to the history element in next (diskbased) release.
491 	 */
492 	direction = first < last ? H_PREV : H_NEXT;
493 
494 	/*
495 	 * If editing, grab a temp file.
496 	 */
497 	if (editor) {
498 		int fd;
499 
500 		INTOFF;		/* easier */
501 		snprintf(editfile, sizeof(editfile),
502 		    "%s_shXXXXXX", _PATH_TMP);
503 		if ((fd = mkstemp(editfile)) < 0)
504 			error("can't create temporary file %s", editfile);
505 		if ((efp = fdopen(fd, "w")) == NULL) {
506 			close(fd);
507 			error("can't allocate stdio buffer for temp");
508 		}
509 		VTRACE(DBG_HISTORY, ("histcmd created \"%s\" for edit buffer"
510 		    " fd=%d\n", editfile, fd));
511 	}
512 
513 	/*
514 	 * Loop through selected history events.  If listing or executing,
515 	 * do it now.  Otherwise, put into temp file and call the editor
516 	 * after.
517 	 *
518 	 * The history interface needs rethinking, as the following
519 	 * convolutions will demonstrate.
520 	 */
521 	history(hist, &he, H_FIRST);
522 	retval = history(hist, &he, H_NEXT_EVENT, first);
523 	for ( ; retval != -1; retval = history(hist, &he, direction)) {
524 		if (lflg) {
525 			if (!nflg)
526 				out1fmt("%5d ", he.num);
527 			out1str(he.str);
528 		} else {
529 			const char *s = pat ?
530 			   fc_replace(he.str, pat, repl) : he.str;
531 
532 			if (sflg) {
533 				VTRACE(DBG_HISTORY, ("histcmd -s \"%s\"\n", s));
534 				if (displayhist) {
535 					out2str(s);
536 				}
537 
538 				evalstring(strcpy(stalloc(strlen(s)+1), s), 0);
539 				if (displayhist && hist) {
540 					/*
541 					 *  XXX what about recursive and
542 					 *  relative histnums.
543 					 */
544 					history(hist, &he, H_ENTER, s);
545 				}
546 
547 				break;
548 			} else
549 				fputs(s, efp);
550 		}
551 		/*
552 		 * At end?  (if we were to lose last, we'd sure be
553 		 * messed up).
554 		 */
555 		if (he.num == last)
556 			break;
557 	}
558 	if (editor) {
559 		char *editcmd;
560 		size_t cmdlen;
561 
562 		fclose(efp);
563 		cmdlen = strlen(editor) + strlen(editfile) + 2;
564 		editcmd = stalloc(cmdlen);
565 		snprintf(editcmd, cmdlen, "%s %s", editor, editfile);
566 		VTRACE(DBG_HISTORY, ("histcmd editing: \"%s\"\n", editcmd));
567 		evalstring(editcmd, 0);	/* XXX - should use no JC command */
568 		stunalloc(editcmd);
569 		VTRACE(DBG_HISTORY, ("histcmd read cmds from %s\n", editfile));
570 		readcmdfile(editfile);	/* XXX - should read back - quick tst */
571 		VTRACE(DBG_HISTORY, ("histcmd unlink %s\n", editfile));
572 		unlink(editfile);
573 		editfile[0] = '\0';
574 		INTON;
575 	}
576 
577 	if (lflg == 0 && active > 0)
578 		--active;
579 	if (displayhist)
580 		displayhist = 0;
581 	return 0;
582 }
583 
584 static const char *
585 fc_replace(const char *s, char *p, char *r)
586 {
587 	char *dest;
588 	int plen = strlen(p);
589 
590 	VTRACE(DBG_HISTORY, ("histcmd s/%s/%s/ in \"%s\" -> ", p, r, s));
591 	STARTSTACKSTR(dest);
592 	while (*s) {
593 		if (*s == *p && strncmp(s, p, plen) == 0) {
594 			while (*r)
595 				STPUTC(*r++, dest);
596 			s += plen;
597 			*p = '\0';	/* so no more matches */
598 		} else
599 			STPUTC(*s++, dest);
600 	}
601 	STACKSTRNUL(dest);
602 	dest = grabstackstr(dest);
603 	VTRACE(DBG_HISTORY, ("\"%s\"\n", dest));
604 
605 	return dest;
606 }
607 
608 
609 /*
610  * Comparator function for qsort(). The use of curpos here is to skip
611  * characters that we already know to compare equal (common prefix).
612  */
613 static int
614 comparator(const void *a, const void *b)
615 {
616 	return strcmp(*(char *const *)a + curpos,
617 		*(char *const *)b + curpos);
618 }
619 
620 /*
621  * This function is passed to libedit's fn_complete(). The library will
622  * use it instead of its standard function to find matches, which
623  * searches for files in current directory. If we're at the start of the
624  * line, we want to look for available commands from all paths in $PATH.
625  */
626 static char **
627 sh_matches(const char *text, int start, int end)
628 {
629 	char *free_path = NULL, *dirname, *path;
630 	char **matches = NULL;
631 	size_t i = 0, size = 16;
632 
633 	if (start > 0)
634 		return NULL;
635 	curpos = end - start;
636 	if ((free_path = path = strdup(pathval())) == NULL)
637 		goto out;
638 	if ((matches = malloc(size * sizeof(matches[0]))) == NULL)
639 		goto out;
640 	while ((dirname = strsep(&path, ":")) != NULL) {
641 		struct dirent *entry;
642 		DIR *dir;
643 		int dfd;
644 
645 		if ((dir = opendir(dirname)) == NULL)
646 			continue;
647 		if ((dfd = dirfd(dir)) == -1)
648 			continue;
649 		while ((entry = readdir(dir)) != NULL) {
650 			struct stat statb;
651 
652 			if (strncmp(entry->d_name, text, curpos) != 0)
653 				continue;
654 			if (entry->d_type == DT_UNKNOWN ||
655 			    entry->d_type == DT_LNK) {
656 				if (fstatat(dfd, entry->d_name, &statb, 0)
657 				    == -1)
658 					continue;
659 				if (!S_ISREG(statb.st_mode))
660 					continue;
661 			} else if (entry->d_type != DT_REG)
662 				continue;
663 			if (++i >= size - 1) {
664 				size *= 2;
665 				if (reallocarr(&matches, size,
666 				    sizeof(*matches)))
667 				{
668 					closedir(dir);
669 					goto out;
670 				}
671 			}
672 			matches[i] = strdup(entry->d_name);
673 		}
674 		closedir(dir);
675 	}
676  out:;
677 	free(free_path);
678 	if (i == 0) {
679 		free(matches);
680 		return NULL;
681 	}
682 	if (i == 1) {
683 		matches[0] = strdup(matches[1]);
684 		matches[i + 1] = NULL;
685 	} else {
686 		size_t j, k;
687 
688 		qsort(matches + 1, i, sizeof(matches[0]), comparator);
689 		for (j = 1, k = 2; k <= i; k++)
690 			if (strcmp(matches[j] + curpos, matches[k] + curpos)
691 			    == 0)
692 				free(matches[k]);
693 			else
694 				matches[++j] = matches[k];
695 		matches[0] = strdup(text);
696 		matches[j + 1] = NULL;
697 	}
698 	return matches;
699 }
700 
701 /*
702  * This is passed to el_set(el, EL_ADDFN, ...) so that it's possible to
703  * bind a key (tab by default) to execute the function.
704  */
705 unsigned char
706 sh_complete(EditLine *sel, int ch __unused)
707 {
708 	return (unsigned char)fn_complete2(sel, NULL, sh_matches,
709 		L" \t\n\"\\'`@$><=;|&{(", NULL, NULL, (size_t)100,
710 		NULL, &((int) {0}), NULL, NULL, FN_QUOTE_MATCH);
711 }
712 
713 static int
714 not_fcnumber(const char *s)
715 {
716 	if (s == NULL)
717 		return 0;
718 	if (*s == '-')
719 		s++;
720 	return !is_number(s);
721 }
722 
723 static int
724 str_to_event(const char *str, int last)
725 {
726 	HistEvent he;
727 	const char *s = str;
728 	int relative = 0;
729 	int i, retval;
730 
731 	retval = history(hist, &he, H_FIRST);
732 	switch (*s) {
733 	case '-':
734 		relative = 1;
735 		/*FALLTHROUGH*/
736 	case '+':
737 		s++;
738 	}
739 	if (is_number(s)) {
740 		i = number(s);
741 		if (relative) {
742 			while (retval != -1 && i--) {
743 				retval = history(hist, &he, H_NEXT);
744 			}
745 			if (retval == -1)
746 				retval = history(hist, &he, H_LAST);
747 		} else {
748 			retval = history(hist, &he, H_NEXT_EVENT, i);
749 			if (retval == -1) {
750 				/*
751 				 * the notion of first and last is
752 				 * backwards to that of the history package
753 				 */
754 				retval = history(hist, &he,
755 						last ? H_FIRST : H_LAST);
756 			}
757 		}
758 		if (retval == -1)
759 			return -1;
760 	} else {
761 		/*
762 		 * pattern
763 		 */
764 		retval = history(hist, &he, H_PREV_STR, str);
765 		if (retval == -1)
766 			error("history pattern not found: %s", str);
767 	}
768 	return he.num;
769 }
770 
771 #else	/* defined(SMALL) */
772 
773 int
774 histcmd(int argc, char **argv)
775 {
776 	error("not compiled with history support");
777 	/* NOTREACHED */
778 }
779 
780 int
781 inputrc(int argc, char **argv)
782 {
783 	error("not compiled with history support");
784 	/* NOTREACHED */
785 }
786 
787 #endif	/* SMALL */
788