1/*-
2 * Copyright (c) 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/param.h>
34#include <sys/stat.h>
35#include <dirent.h>
36#include <errno.h>
37#include <fcntl.h>
38#include <limits.h>
39#include <paths.h>
40#include <stdbool.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <unistd.h>
44/*
45 * Editline and history functions (and glue).
46 */
47#include "alias.h"
48#include "exec.h"
49#include "shell.h"
50#include "parser.h"
51#include "var.h"
52#include "options.h"
53#include "main.h"
54#include "output.h"
55#include "mystring.h"
56#include "builtins.h"
57#ifndef NO_HISTORY
58#include "myhistedit.h"
59#include "error.h"
60#include "eval.h"
61#include "memalloc.h"
62
63#define MAXHISTLOOPS	4	/* max recursions through fc */
64#define DEFEDITOR	"ed"	/* default editor *should* be $EDITOR */
65
66History *hist;	/* history cookie */
67EditLine *el;	/* editline cookie */
68int displayhist;
69static int savehist;
70static FILE *el_in, *el_out;
71static bool in_command_completion;
72
73static char *fc_replace(const char *, char *, char *);
74static int not_fcnumber(const char *);
75static int str_to_event(const char *, int);
76static int comparator(const void *, const void *, void *);
77static char **sh_matches(const char *, int, int);
78static const char *append_char_function(const char *);
79static unsigned char sh_complete(EditLine *, int);
80
81static const char *
82get_histfile(void)
83{
84	const char *histfile;
85
86	/* don't try to save if the history size is 0 */
87	if (hist == NULL || !strcmp(histsizeval(), "0"))
88		return (NULL);
89	histfile = expandstr("${HISTFILE-${HOME-}/.sh_history}");
90
91	if (histfile[0] == '\0')
92		return (NULL);
93	return (histfile);
94}
95
96void
97histsave(void)
98{
99	HistEvent he;
100	char *histtmpname = NULL;
101	const char *histfile;
102	int fd;
103	FILE *f;
104
105	if (!savehist || (histfile = get_histfile()) == NULL)
106		return;
107	INTOFF;
108	asprintf(&histtmpname, "%s.XXXXXXXXXX", histfile);
109	if (histtmpname == NULL) {
110		INTON;
111		return;
112	}
113	fd = mkstemp(histtmpname);
114	if (fd == -1 || (f = fdopen(fd, "w")) == NULL) {
115		free(histtmpname);
116		INTON;
117		return;
118	}
119	if (history(hist, &he, H_SAVE_FP, f) < 1 ||
120	    rename(histtmpname, histfile) == -1)
121		unlink(histtmpname);
122	fclose(f);
123	free(histtmpname);
124	INTON;
125
126}
127
128void
129histload(void)
130{
131	const char *histfile;
132	HistEvent he;
133
134	if ((histfile = get_histfile()) == NULL)
135		return;
136	errno = 0;
137	if (history(hist, &he, H_LOAD, histfile) != -1 || errno == ENOENT)
138		savehist = 1;
139}
140
141/*
142 * Set history and editing status.  Called whenever the status may
143 * have changed (figures out what to do).
144 */
145void
146histedit(void)
147{
148
149#define editing (Eflag || Vflag)
150
151	if (iflag) {
152		if (!hist) {
153			/*
154			 * turn history on
155			 */
156			INTOFF;
157			hist = history_init();
158			INTON;
159
160			if (hist != NULL)
161				sethistsize(histsizeval());
162			else
163				out2fmt_flush("sh: can't initialize history\n");
164		}
165		if (editing && !el && isatty(0)) { /* && isatty(2) ??? */
166			/*
167			 * turn editing on
168			 */
169			char *term;
170
171			INTOFF;
172			if (el_in == NULL)
173				el_in = fdopen(0, "r");
174			if (el_out == NULL)
175				el_out = fdopen(2, "w");
176			if (el_in == NULL || el_out == NULL)
177				goto bad;
178			term = lookupvar("TERM");
179			if (term)
180				setenv("TERM", term, 1);
181			else
182				unsetenv("TERM");
183			el = el_init(arg0, el_in, el_out, el_out);
184			if (el != NULL) {
185				if (hist)
186					el_set(el, EL_HIST, history, hist);
187				el_set(el, EL_PROMPT_ESC, getprompt, '\001');
188				el_set(el, EL_ADDFN, "sh-complete",
189				    "Filename completion",
190				    sh_complete);
191			} else {
192bad:
193				out2fmt_flush("sh: can't initialize editing\n");
194			}
195			INTON;
196		} else if (!editing && el) {
197			INTOFF;
198			el_end(el);
199			el = NULL;
200			INTON;
201		}
202		if (el) {
203			if (Vflag)
204				el_set(el, EL_EDITOR, "vi");
205			else if (Eflag) {
206				el_set(el, EL_EDITOR, "emacs");
207			}
208			el_set(el, EL_BIND, "^I", "sh-complete", NULL);
209			el_source(el, NULL);
210		}
211	} else {
212		INTOFF;
213		if (el) {	/* no editing if not interactive */
214			el_end(el);
215			el = NULL;
216		}
217		if (hist) {
218			history_end(hist);
219			hist = NULL;
220		}
221		INTON;
222	}
223}
224
225
226void
227sethistsize(const char *hs)
228{
229	int histsize;
230	HistEvent he;
231
232	if (hist != NULL) {
233		if (hs == NULL || !is_number(hs))
234			histsize = 100;
235		else
236			histsize = atoi(hs);
237		history(hist, &he, H_SETSIZE, histsize);
238		history(hist, &he, H_SETUNIQUE, 1);
239	}
240}
241
242void
243setterm(const char *term)
244{
245	if (rootshell && el != NULL && term != NULL)
246		el_set(el, EL_TERMINAL, term);
247}
248
249int
250histcmd(int argc, char **argv __unused)
251{
252	const char *editor = NULL;
253	HistEvent he;
254	int lflg = 0, nflg = 0, rflg = 0, sflg = 0;
255	int i, retval;
256	const char *firststr, *laststr;
257	int first, last, direction;
258	char *pat = NULL, *repl = NULL;
259	static int active = 0;
260	struct jmploc jmploc;
261	struct jmploc *savehandler;
262	char editfilestr[PATH_MAX];
263	char *volatile editfile;
264	FILE *efp = NULL;
265	int oldhistnum;
266
267	if (hist == NULL)
268		error("history not active");
269
270	if (argc == 1)
271		error("missing history argument");
272
273	while (not_fcnumber(*argptr))
274		do {
275			switch (nextopt("e:lnrs")) {
276			case 'e':
277				editor = shoptarg;
278				break;
279			case 'l':
280				lflg = 1;
281				break;
282			case 'n':
283				nflg = 1;
284				break;
285			case 'r':
286				rflg = 1;
287				break;
288			case 's':
289				sflg = 1;
290				break;
291			case '\0':
292				goto operands;
293			}
294		} while (nextopt_optptr != NULL);
295operands:
296	savehandler = handler;
297	/*
298	 * If executing...
299	 */
300	if (lflg == 0 || editor || sflg) {
301		lflg = 0;	/* ignore */
302		editfile = NULL;
303		/*
304		 * Catch interrupts to reset active counter and
305		 * cleanup temp files.
306		 */
307		if (setjmp(jmploc.loc)) {
308			active = 0;
309			if (editfile)
310				unlink(editfile);
311			handler = savehandler;
312			longjmp(handler->loc, 1);
313		}
314		handler = &jmploc;
315		if (++active > MAXHISTLOOPS) {
316			active = 0;
317			displayhist = 0;
318			error("called recursively too many times");
319		}
320		/*
321		 * Set editor.
322		 */
323		if (sflg == 0) {
324			if (editor == NULL &&
325			    (editor = bltinlookup("FCEDIT", 1)) == NULL &&
326			    (editor = bltinlookup("EDITOR", 1)) == NULL)
327				editor = DEFEDITOR;
328			if (editor[0] == '-' && editor[1] == '\0') {
329				sflg = 1;	/* no edit */
330				editor = NULL;
331			}
332		}
333	}
334
335	/*
336	 * If executing, parse [old=new] now
337	 */
338	if (lflg == 0 && *argptr != NULL &&
339	     ((repl = strchr(*argptr, '=')) != NULL)) {
340		pat = *argptr;
341		*repl++ = '\0';
342		argptr++;
343	}
344	/*
345	 * determine [first] and [last]
346	 */
347	if (*argptr == NULL) {
348		firststr = lflg ? "-16" : "-1";
349		laststr = "-1";
350	} else if (argptr[1] == NULL) {
351		firststr = argptr[0];
352		laststr = lflg ? "-1" : argptr[0];
353	} else if (argptr[2] == NULL) {
354		firststr = argptr[0];
355		laststr = argptr[1];
356	} else
357		error("too many arguments");
358	/*
359	 * Turn into event numbers.
360	 */
361	first = str_to_event(firststr, 0);
362	last = str_to_event(laststr, 1);
363
364	if (rflg) {
365		i = last;
366		last = first;
367		first = i;
368	}
369	/*
370	 * XXX - this should not depend on the event numbers
371	 * always increasing.  Add sequence numbers or offset
372	 * to the history element in next (diskbased) release.
373	 */
374	direction = first < last ? H_PREV : H_NEXT;
375
376	/*
377	 * If editing, grab a temp file.
378	 */
379	if (editor) {
380		int fd;
381		INTOFF;		/* easier */
382		sprintf(editfilestr, "%s/_shXXXXXX", _PATH_TMP);
383		if ((fd = mkstemp(editfilestr)) < 0)
384			error("can't create temporary file %s", editfile);
385		editfile = editfilestr;
386		if ((efp = fdopen(fd, "w")) == NULL) {
387			close(fd);
388			error("Out of space");
389		}
390	}
391
392	/*
393	 * Loop through selected history events.  If listing or executing,
394	 * do it now.  Otherwise, put into temp file and call the editor
395	 * after.
396	 *
397	 * The history interface needs rethinking, as the following
398	 * convolutions will demonstrate.
399	 */
400	history(hist, &he, H_FIRST);
401	retval = history(hist, &he, H_NEXT_EVENT, first);
402	for (;retval != -1; retval = history(hist, &he, direction)) {
403		if (lflg) {
404			if (!nflg)
405				out1fmt("%5d ", he.num);
406			out1str(he.str);
407		} else {
408			const char *s = pat ?
409			   fc_replace(he.str, pat, repl) : he.str;
410
411			if (sflg) {
412				if (displayhist) {
413					out2str(s);
414					flushout(out2);
415				}
416				evalstring(s, 0);
417				if (displayhist && hist) {
418					/*
419					 *  XXX what about recursive and
420					 *  relative histnums.
421					 */
422					oldhistnum = he.num;
423					history(hist, &he, H_ENTER, s);
424					/*
425					 * XXX H_ENTER moves the internal
426					 * cursor, set it back to the current
427					 * entry.
428					 */
429					history(hist, &he,
430					    H_NEXT_EVENT, oldhistnum);
431				}
432			} else
433				fputs(s, efp);
434		}
435		/*
436		 * At end?  (if we were to lose last, we'd sure be
437		 * messed up).
438		 */
439		if (he.num == last)
440			break;
441	}
442	if (editor) {
443		char *editcmd;
444
445		fclose(efp);
446		INTON;
447		editcmd = stalloc(strlen(editor) + strlen(editfile) + 2);
448		sprintf(editcmd, "%s %s", editor, editfile);
449		evalstring(editcmd, 0);	/* XXX - should use no JC command */
450		readcmdfile(editfile, 0 /* verify */);	/* XXX - should read back - quick tst */
451		unlink(editfile);
452	}
453
454	if (lflg == 0 && active > 0)
455		--active;
456	if (displayhist)
457		displayhist = 0;
458	handler = savehandler;
459	return 0;
460}
461
462static char *
463fc_replace(const char *s, char *p, char *r)
464{
465	char *dest;
466	int plen = strlen(p);
467
468	STARTSTACKSTR(dest);
469	while (*s) {
470		if (*s == *p && strncmp(s, p, plen) == 0) {
471			STPUTS(r, dest);
472			s += plen;
473			*p = '\0';	/* so no more matches */
474		} else
475			STPUTC(*s++, dest);
476	}
477	STPUTC('\0', dest);
478	dest = grabstackstr(dest);
479
480	return (dest);
481}
482
483static int
484not_fcnumber(const char *s)
485{
486	if (s == NULL)
487		return (0);
488	if (*s == '-')
489		s++;
490	return (!is_number(s));
491}
492
493static int
494str_to_event(const char *str, int last)
495{
496	HistEvent he;
497	const char *s = str;
498	int relative = 0;
499	int i, retval;
500
501	retval = history(hist, &he, H_FIRST);
502	switch (*s) {
503	case '-':
504		relative = 1;
505		/*FALLTHROUGH*/
506	case '+':
507		s++;
508	}
509	if (is_number(s)) {
510		i = atoi(s);
511		if (relative) {
512			while (retval != -1 && i--) {
513				retval = history(hist, &he, H_NEXT);
514			}
515			if (retval == -1)
516				retval = history(hist, &he, H_LAST);
517		} else {
518			retval = history(hist, &he, H_NEXT_EVENT, i);
519			if (retval == -1) {
520				/*
521				 * the notion of first and last is
522				 * backwards to that of the history package
523				 */
524				retval = history(hist, &he, last ? H_FIRST : H_LAST);
525			}
526		}
527		if (retval == -1)
528			error("history number %s not found (internal error)",
529			       str);
530	} else {
531		/*
532		 * pattern
533		 */
534		retval = history(hist, &he, H_PREV_STR, str);
535		if (retval == -1)
536			error("history pattern not found: %s", str);
537	}
538	return (he.num);
539}
540
541int
542bindcmd(int argc, char **argv)
543{
544	int ret;
545	FILE *old;
546	FILE *out;
547
548	if (el == NULL)
549		error("line editing is disabled");
550
551	INTOFF;
552
553	out = out1fp();
554	if (out == NULL)
555		error("Out of space");
556
557	el_get(el, EL_GETFP, 1, &old);
558	el_set(el, EL_SETFP, 1, out);
559
560	ret = el_parse(el, argc, __DECONST(const char **, argv));
561
562	el_set(el, EL_SETFP, 1, old);
563
564	fclose(out);
565
566	if (argc > 1 && argv[1][0] == '-' &&
567	    memchr("ve", argv[1][1], 2) != NULL) {
568		Vflag = argv[1][1] == 'v';
569		Eflag = !Vflag;
570		histedit();
571	}
572
573	INTON;
574
575	return ret;
576}
577
578/*
579 * Comparator function for qsort(). The use of curpos here is to skip
580 * characters that we already know to compare equal (common prefix).
581 */
582static int
583comparator(const void *a, const void *b, void *thunk)
584{
585	size_t curpos = (intptr_t)thunk;
586
587	return (strcmp(*(char *const *)a + curpos,
588		*(char *const *)b + curpos));
589}
590
591static char
592**add_match(char **matches, size_t i, size_t *size, char *match_copy)
593{
594	if (match_copy == NULL)
595		return (NULL);
596	matches[i] = match_copy;
597	if (i >= *size - 1) {
598		*size *= 2;
599		matches = reallocarray(matches, *size, sizeof(matches[0]));
600	}
601
602	return (matches);
603}
604
605/*
606 * This function is passed to libedit's fn_complete2(). The library will use
607 * it instead of its standard function that finds matching files in current
608 * directory. If we're at the start of the line, we want to look for
609 * available commands from all paths in $PATH.
610 */
611static char
612**sh_matches(const char *text, int start, int end)
613{
614	char *free_path = NULL, *path;
615	const char *dirname;
616	char **matches = NULL, **rmatches;
617	size_t i = 0, size = 16, uniq;
618	size_t curpos = end - start, lcstring = -1;
619	struct cmdentry e;
620
621	in_command_completion = false;
622	if (start > 0 || memchr("/.~", text[0], 3) != NULL)
623		return (NULL);
624	in_command_completion = true;
625	if ((free_path = path = strdup(pathval())) == NULL)
626		goto out;
627	if ((matches = malloc(size * sizeof(matches[0]))) == NULL)
628		goto out;
629	while ((dirname = strsep(&path, ":")) != NULL) {
630		struct dirent *entry;
631		DIR *dir;
632		int dfd;
633
634		dir = opendir(dirname[0] == '\0' ? "." : dirname);
635		if (dir == NULL)
636			continue;
637		if ((dfd = dirfd(dir)) == -1) {
638			closedir(dir);
639			continue;
640		}
641		while ((entry = readdir(dir)) != NULL) {
642			struct stat statb;
643
644			if (strncmp(entry->d_name, text, curpos) != 0)
645				continue;
646			if (entry->d_type == DT_UNKNOWN || entry->d_type == DT_LNK) {
647				if (fstatat(dfd, entry->d_name, &statb, 0) == -1)
648					continue;
649				if (!S_ISREG(statb.st_mode))
650					continue;
651			} else if (entry->d_type != DT_REG)
652				continue;
653			rmatches = add_match(matches, ++i, &size,
654				strdup(entry->d_name));
655			if (rmatches == NULL) {
656				closedir(dir);
657				goto out;
658			}
659			matches = rmatches;
660		}
661		closedir(dir);
662	}
663	for (const unsigned char *bp = builtincmd; *bp != 0; bp += 2 + bp[0]) {
664		if (curpos > bp[0] || memcmp(bp + 2, text, curpos) != 0)
665			continue;
666		rmatches = add_match(matches, ++i, &size, strndup(bp + 2, bp[0]));
667		if (rmatches == NULL)
668			goto out;
669		matches = rmatches;
670	}
671	for (const struct alias *ap = NULL; (ap = iteralias(ap)) != NULL;) {
672		if (strncmp(ap->name, text, curpos) != 0)
673			continue;
674		rmatches = add_match(matches, ++i, &size, strdup(ap->name));
675		if (rmatches == NULL)
676			goto out;
677		matches = rmatches;
678	}
679	for (const void *a = NULL; (a = itercmd(a, &e)) != NULL;) {
680		if (e.cmdtype != CMDFUNCTION)
681			continue;
682		if (strncmp(e.cmdname, text, curpos) != 0)
683			continue;
684		rmatches = add_match(matches, ++i, &size, strdup(e.cmdname));
685		if (rmatches == NULL)
686			goto out;
687		matches = rmatches;
688	}
689out:
690	free(free_path);
691	if (i == 0) {
692		free(matches);
693		return (NULL);
694	}
695	uniq = 1;
696	if (i > 1) {
697		qsort_s(matches + 1, i, sizeof(matches[0]), comparator,
698			(void *)(intptr_t)curpos);
699		for (size_t k = 2; k <= i; k++) {
700			const char *l = matches[uniq] + curpos;
701			const char *r = matches[k] + curpos;
702			size_t common = 0;
703
704			while (*l != '\0' && *r != '\0' && *l == *r)
705				(void)l++, r++, common++;
706			if (common < lcstring)
707				lcstring = common;
708			if (*l == *r)
709				free(matches[k]);
710			else
711				matches[++uniq] = matches[k];
712		}
713	}
714	matches[uniq + 1] = NULL;
715	/*
716	 * matches[0] is special: it's not a real matching file name but
717	 * a common prefix for all matching names. It can't be null, unlike
718	 * any other element of the array. When strings matches[0] and
719	 * matches[1] compare equal and matches[2] is null that means to
720	 * libedit that there is only a single match. It will then replace
721	 * user input with possibly escaped string in matches[0] which is the
722	 * reason to copy the full name of the only match.
723	 */
724	if (uniq == 1)
725		matches[0] = strdup(matches[1]);
726	else if (lcstring != (size_t)-1)
727		matches[0] = strndup(matches[1], curpos + lcstring);
728	else
729		matches[0] = strdup(text);
730	if (matches[0] == NULL) {
731		for (size_t k = 1; k <= uniq; k++)
732			free(matches[k]);
733		free(matches);
734		return (NULL);
735	}
736	return (matches);
737}
738
739/*
740 * If we don't specify this function as app_func in the call to fn_complete2,
741 * libedit will use the default one, which adds a " " to plain files and
742 * a "/" to directories regardless of whether it's a command name or a plain
743 * path (relative or absolute). We never want to add "/" to commands.
744 *
745 * For example, after I did "mkdir rmdir", "rmdi" would be autocompleted to
746 * "rmdir/" instead of "rmdir ".
747 */
748static const char *
749append_char_function(const char *name)
750{
751	struct stat stbuf;
752	char *expname = name[0] == '~' ? fn_tilde_expand(name) : NULL;
753	const char *rs;
754
755	if (!in_command_completion &&
756	    stat(expname ? expname : name, &stbuf) == 0 &&
757	    S_ISDIR(stbuf.st_mode))
758		rs = "/";
759	else
760		rs = " ";
761	free(expname);
762	return (rs);
763}
764
765/*
766 * This is passed to el_set(el, EL_ADDFN, ...) so that it's possible to
767 * bind a key (tab by default) to execute the function.
768 */
769unsigned char
770sh_complete(EditLine *sel, int ch __unused)
771{
772	return (unsigned char)fn_complete2(sel, NULL, sh_matches,
773		L" \t\n\"\\'`@$><=;|&{(", NULL, append_char_function,
774		(size_t)100, NULL, &((int) {0}), NULL, NULL, FN_QUOTE_MATCH);
775}
776
777#else
778#include "error.h"
779
780int
781histcmd(int argc __unused, char **argv __unused)
782{
783
784	error("not compiled with history support");
785	/*NOTREACHED*/
786	return (0);
787}
788
789int
790bindcmd(int argc __unused, char **argv __unused)
791{
792
793	error("not compiled with line editing support");
794	return (0);
795}
796#endif
797