aboutsummaryrefslogtreecommitdiff
path: root/shell/cmdedit.c
blob: b3e7fd58c9f1a227dd7f2b923aafc8711c85e6da (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
/* vi: set sw=4 ts=4: */
/*
 * Termios command line History and Editting for NetBSD sh (ash)
 * Copyright (c) 1999
 *      Main code:            Adam Rogoyski <rogoyski@cs.utexas.edu> 
 *      Etc:                  Dave Cinege <dcinege@psychosis.com>
 *      Adjusted for busybox: Erik Andersen <andersee@debian.org>
 *
 * You may use this code as you wish, so long as the original author(s)
 * are attributed in any redistributions of the source code.
 * This code is 'as is' with no warranty.
 * This code may safely be consumed by a BSD or GPL license.
 *
 * v 0.5  19990328      Initial release 
 *
 * Future plans: Simple file and path name completion. (like BASH)
 *
 */

/*
   Usage and Known bugs:
   Terminal key codes are not extensive, and more will probably
   need to be added. This version was created on Debian GNU/Linux 2.x.
   Delete, Backspace, Home, End, and the arrow keys were tested
   to work in an Xterm and console. Ctrl-A also works as Home.
   Ctrl-E also works as End. The binary size increase is <3K.

   Editting will not display correctly for lines greater then the 
   terminal width. (more then one line.) However, history will.
 */

#include "internal.h"
#ifdef BB_FEATURE_SH_COMMAND_EDITING

#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <termio.h>
#include <ctype.h>
#include <signal.h>


#define  MAX_HISTORY   15		/* Maximum length of the linked list for the command line history */

#define ESC	27
#define DEL	127
#define member(c, s) ((c) ? ((char *)strchr ((s), (c)) != (char *)NULL) : 0)
#define whitespace(c) (((c) == ' ') || ((c) == '\t'))

static struct history *his_front = NULL;	/* First element in command line list */
static struct history *his_end = NULL;	/* Last element in command line list */
static struct termio old_term, new_term;	/* Current termio and the previous termio before starting ash */

static int history_counter = 0;	/* Number of commands in history list */
static int reset_term = 0;		/* Set to true if the terminal needs to be reset upon exit */
char *parsenextc;				/* copy of parsefile->nextc */

struct history {
	char *s;
	struct history *p;
	struct history *n;
};


/* Version of write which resumes after a signal is caught.  */
int xwrite(int fd, char *buf, int nbytes)
{
	int ntry;
	int i;
	int n;

	n = nbytes;
	ntry = 0;
	for (;;) {
		i = write(fd, buf, n);
		if (i > 0) {
			if ((n -= i) <= 0)
				return nbytes;
			buf += i;
			ntry = 0;
		} else if (i == 0) {
			if (++ntry > 10)
				return nbytes - n;
		} else if (errno != EINTR) {
			return -1;
		}
	}
}


/* Version of ioctl that retries after a signal is caught.  */
int xioctl(int fd, unsigned long request, char *arg)
{
	int i;

	while ((i = ioctl(fd, request, arg)) == -1 && errno == EINTR);
	return i;
}


void cmdedit_reset_term(void)
{
	if (reset_term)
		xioctl(fileno(stdin), TCSETA, (void *) &old_term);
}

void prepareToDie(int sig)
{
	cmdedit_reset_term();
	fprintf(stdout, "\n");
	exit(TRUE);
}

void input_home(int outputFd, int *cursor)
{								/* Command line input routines */
	while (*cursor > 0) {
		xwrite(outputFd, "\b", 1);
		--*cursor;
	}
}


void input_delete(int outputFd, int cursor)
{
	int j = 0;

	memmove(parsenextc + cursor, parsenextc + cursor + 1,
			BUFSIZ - cursor - 1);
	for (j = cursor; j < (BUFSIZ - 1); j++) {
		if (!*(parsenextc + j))
			break;
		else
			xwrite(outputFd, (parsenextc + j), 1);
	}

	xwrite(outputFd, " \b", 2);

	while (j-- > cursor)
		xwrite(outputFd, "\b", 1);
}


void input_end(int outputFd, int *cursor, int len)
{
	while (*cursor < len) {
		xwrite(outputFd, "\033[C", 3);
		++*cursor;
	}
}


void input_backspace(int outputFd, int *cursor, int *len)
{
	int j = 0;

	if (*cursor > 0) {
		xwrite(outputFd, "\b \b", 3);
		--*cursor;
		memmove(parsenextc + *cursor, parsenextc + *cursor + 1,
				BUFSIZ - *cursor + 1);

		for (j = *cursor; j < (BUFSIZ - 1); j++) {
			if (!*(parsenextc + j))
				break;
			else
				xwrite(outputFd, (parsenextc + j), 1);
		}

		xwrite(outputFd, " \b", 2);

		while (j-- > *cursor)
			xwrite(outputFd, "\b", 1);

		--*len;
	}
}

char** username_completion_matches(char* command, int *num_matches)
{
	char **matches = (char **) NULL;
	*num_matches=0;
	fprintf(stderr, "\nin username_completion_matches\n");
	return (matches);
}

#include <dirent.h>
char** find_path_executable_n_cwd_matches(char* command, int *num_matches)
{
	char *dirName;
	char **matches = (char **) NULL;
	DIR *dir;
	struct dirent *next;
			
	matches = malloc( sizeof(char*)*50);

	/* Stick a wildcard onto the command, for later use */
	strcat( command, "*");

	/* Now wall the current directory */
	dirName = get_current_dir_name();
	dir = opendir(dirName);
	if (!dir) {
		/* Don't print an error, just shut up and return */
		*num_matches=0;
		return (matches);
	}
	while ((next = readdir(dir)) != NULL) {

		/* Some quick sanity checks */
		if ((strcmp(next->d_name, "..") == 0)
			|| (strcmp(next->d_name, ".") == 0)) {
			continue;
		} 
		/* See if this matches */
		if (check_wildcard_match(next->d_name, command) == TRUE) {
			/* Cool, found a match.  Add it to the list */
			matches[*num_matches] = malloc(strlen(next->d_name)+1);
			strcpy( matches[*num_matches], next->d_name);
			++*num_matches;
			//matches = realloc( matches, sizeof(char*)*(*num_matches));
		}
	}

	return (matches);
}

/*
 * This function is used to grab a character buffer
 * from the input file descriptor and allows you to
 * a string with full command editing (sortof like
 * a mini readline).
 *
 * The following standard commands are not implemented:
 * ESC-b -- Move back one word
 * ESC-f -- Move forward one word
 * ESC-d -- Delete back one word
 * ESC-h -- Delete forward one word
 * CTL-t -- Transpose two characters
 *
 * Furthermore, the "vi" command editing keys are not implemented.
 *
 * TODO: implement TAB command completion. :)
 *
 */
extern int cmdedit_read_input(char* prompt, int inputFd, int outputFd,
							  char command[BUFSIZ])
{

	int nr = 0;
	int len = 0;
	int j = 0;
	int cursor = 0;
	int break_out = 0;
	int ret = 0;
	int lastWasTab = FALSE;
	char c = 0;
	struct history *hp = his_end;

	memset(command, 0, sizeof(command));
	parsenextc = command;
	if (!reset_term) {
		xioctl(inputFd, TCGETA, (void *) &old_term);
		memcpy(&new_term, &old_term, sizeof(struct termio));

		new_term.c_cc[VMIN] = 1;
		new_term.c_cc[VTIME] = 0;
		new_term.c_lflag &= ~ICANON;	/* unbuffered input */
		new_term.c_lflag &= ~ECHO;
		xioctl(inputFd, TCSETA, (void *) &new_term);
		reset_term = 1;
	} else {
		xioctl(inputFd, TCSETA, (void *) &new_term);
	}

	memset(parsenextc, 0, BUFSIZ);

	while (1) {

		if ((ret = read(inputFd, &c, 1)) < 1)
			return ret;

		switch (c) {
		case 1:
			/* Control-a -- Beginning of line */
			input_home(outputFd, &cursor);
		case 5:
			/* Control-e -- End of line */
			input_end(outputFd, &cursor, len);
			break;
		case 2:
			/* Control-b -- Move back one character */
			if (cursor > 0) {
				xwrite(outputFd, "\033[D", 3);
				cursor--;
			}
			break;
		case 6:
			/* Control-f -- Move forward one character */
			if (cursor < len) {
				xwrite(outputFd, "\033[C", 3);
				cursor++;
			}
			break;
		case 4:
			/* Control-d -- Delete one character */
			if (cursor != len) {
				input_delete(outputFd, cursor);
				len--;
			} else if (len == 0) {
				prepareToDie(0);
				exit(0);
			}
			break;
		case 14:
			/* Control-n -- Get next command */
			if (hp && hp->n && hp->n->s) {
				free(hp->s);
				hp->s = strdup(parsenextc);
				hp = hp->n;
				goto hop;
			}
			break;
		case 16:
			/* Control-p -- Get previous command */
			if (hp && hp->p) {
				free(hp->s);
				hp->s = strdup(parsenextc);
				hp = hp->p;
				goto hop;
			}
			break;
		case '\t':
			{
				/* Do TAB completion */
				static int num_matches=0;
				static char **matches = (char **) NULL;
				int pos = cursor;
				

				if (lastWasTab == FALSE) {
					char *tmp, *tmp1, *matchBuf;

					/* For now, we will not bother with trying to distinguish
					 * whether the cursor is in/at a command extression -- we
					 * will always try all possable matches.  If you don't like
					 * that then feel free to fix it.
					 */
					
					/* Make a local copy of the string -- up 
					 * to the position of the cursor */
					matchBuf = (char *) calloc(BUFSIZ, sizeof(char));
					strncpy(matchBuf, parsenextc, cursor);
					tmp=matchBuf;

					/* skip past any command seperator tokens */
					while (*tmp && (tmp1=strpbrk(tmp, ";|&{(`")) != NULL) {
						tmp=++tmp1;
						/* skip any leading white space */
						while (*tmp && isspace(*tmp)) 
							++tmp;
					}

					/* skip any leading white space */
					while (*tmp && isspace(*tmp)) 
						++tmp;

					/* Free up any memory already allocated */
					if (matches) {
						free(matches);
						matches = (char **) NULL;
					}

					/* If the word starts with `~' and there is no slash in the word, 
					 * then try completing this word as a username. */

					/* FIXME -- this check is broken! */
					if (*tmp == '~' && !strchr(tmp, '/'))
						matches = username_completion_matches(tmp, &num_matches);

					/* Try to match any executable in our path and everything 
					 * in the current working directory that matches.  */
					if (!matches)
						matches = find_path_executable_n_cwd_matches(tmp, &num_matches);

					/* Don't leak memory */
					free( matchBuf);

					/* Did we find exactly one match? */
					if (matches && num_matches==1) {
						/* write out the matched command */
						strncpy(parsenextc+pos, matches[0]+pos, strlen(matches[0])-pos);
						len=strlen(parsenextc);
						cursor=len;
						xwrite(outputFd, matches[0]+pos, strlen(matches[0])-pos);
						break;
					}
				} else {
					/* Ok -- the last char was a TAB.  Since they
					 * just hit TAB again, print a list of all the
					 * available choices... */
					if ( matches && num_matches>0 ) {
						int i, col;
						
						/* Go to the next line */
						xwrite(outputFd, "\n", 1);
						/* Print the list of matches */
						for (i=0,col=0; i<num_matches; i++) {
							char foo[17];
							sprintf(foo, "%-14s  ", matches[i]);
							col += xwrite(outputFd, foo, strlen(foo));
							if (col > 60 && matches[i+1] != NULL) {
								xwrite(outputFd, "\n", 1);
								col = 0;
							}
						}
						/* Go to the next line */
						xwrite(outputFd, "\n", 1);
						/* Rewrite the prompt */
						xwrite(outputFd, prompt, strlen(prompt));
						/* Rewrite the command */
						xwrite(outputFd, parsenextc, len);
						/* Put the cursor back to where it used to be */
						for (cursor=len; cursor > pos; cursor--)
							xwrite(outputFd, "\b", 1);
					}
				}
				break;
			}
		case '\b':
		case DEL:
			/* Backspace */
			input_backspace(outputFd, &cursor, &len);
			break;
		case '\n':
			/* Enter */
			*(parsenextc + len++ + 1) = c;
			xwrite(outputFd, &c, 1);
			break_out = 1;
			break;
		case ESC:{
				/* escape sequence follows */
				if ((ret = read(inputFd, &c, 1)) < 1)
					return ret;

				if (c == '[') {	/* 91 */
					if ((ret = read(inputFd, &c, 1)) < 1)
						return ret;

					switch (c) {
					case 'A':
						/* Up Arrow -- Get previous command */
						if (hp && hp->p) {
							free(hp->s);
							hp->s = strdup(parsenextc);
							hp = hp->p;
							goto hop;
						}
						break;
					case 'B':
						/* Down Arrow -- Get next command */
						if (hp && hp->n && hp->n->s) {
							free(hp->s);
							hp->s = strdup(parsenextc);
							hp = hp->n;
							goto hop;
						}
						break;

						/* This is where we rewrite the line 
						 * using the selected history item */
					  hop:
						len = strlen(parsenextc);

						/* return to begining of line */
						for (; cursor > 0; cursor--)
							xwrite(outputFd, "\b", 1);

						/* erase old command */
						for (j = 0; j < len; j++)
							xwrite(outputFd, " ", 1);

						/* return to begining of line */
						for (j = len; j > 0; j--)
							xwrite(outputFd, "\b", 1);

						memset(parsenextc, 0, BUFSIZ);
						len = strlen(parsenextc);
						/* write new command */
						strcpy(parsenextc, hp->s);
						len = strlen(hp->s);
						xwrite(outputFd, parsenextc, len);
						cursor = len;
						break;
					case 'C':
						/* Right Arrow -- Move forward one character */
						if (cursor < len) {
							xwrite(outputFd, "\033[C", 3);
							cursor++;
						}
						break;
					case 'D':
						/* Left Arrow -- Move back one character */
						if (cursor > 0) {
							xwrite(outputFd, "\033[D", 3);
							cursor--;
						}
						break;
					case '3':
						/* Delete */
						if (cursor != len) {
							input_delete(outputFd, cursor);
							len--;
						}
						break;
					case '1':
						/* Home (Ctrl-A) */
						input_home(outputFd, &cursor);
						break;
					case '4':
						/* End (Ctrl-E) */
						input_end(outputFd, &cursor, len);
						break;
					}
					if (c == '1' || c == '3' || c == '4')
						if ((ret = read(inputFd, &c, 1)) < 1)
							return ret;	/* read 126 (~) */
				}
				if (c == 'O') {
					/* 79 */
					if ((ret = read(inputFd, &c, 1)) < 1)
						return ret;
					switch (c) {
					case 'H':
						/* Home (xterm) */
						input_home(outputFd, &cursor);
						break;
					case 'F':
						/* End (xterm) */
						input_end(outputFd, &cursor, len);
						break;
					}
				}
				c = 0;
				break;
			}

		default:				/* If it's regular input, do the normal thing */

			if (!isprint(c))	/* Skip non-printable characters */
				break;

			if (len >= (BUFSIZ - 2))	/* Need to leave space for enter */
				break;

			len++;

			if (cursor == (len - 1)) {	/* Append if at the end of the line */
				*(parsenextc + cursor) = c;
			} else {			/* Insert otherwise */
				memmove(parsenextc + cursor + 1, parsenextc + cursor,
						len - cursor - 1);

				*(parsenextc + cursor) = c;

				for (j = cursor; j < len; j++)
					xwrite(outputFd, parsenextc + j, 1);
				for (; j > cursor; j--)
					xwrite(outputFd, "\033[D", 3);
			}

			cursor++;
			xwrite(outputFd, &c, 1);
			break;
		}
		if (c == '\t')
			lastWasTab = TRUE;
		else
			lastWasTab = FALSE;

		if (break_out)			/* Enter is the command terminator, no more input. */
			break;
	}

	nr = len + 1;
	xioctl(inputFd, TCSETA, (void *) &old_term);
	reset_term = 0;


	/* Handle command history log */
	if (*(parsenextc)) {

		struct history *h = his_end;

		if (!h) {
			/* No previous history */
			h = his_front = malloc(sizeof(struct history));
			h->n = malloc(sizeof(struct history));

			h->p = NULL;
			h->s = strdup(parsenextc);
			h->n->p = h;
			h->n->n = NULL;
			h->n->s = NULL;
			his_end = h->n;
			history_counter++;
		} else {
			/* Add a new history command */
			h->n = malloc(sizeof(struct history));

			h->n->p = h;
			h->n->n = NULL;
			h->n->s = NULL;
			h->s = strdup(parsenextc);
			his_end = h->n;

			/* After max history, remove the oldest command */
			if (history_counter >= MAX_HISTORY) {

				struct history *p = his_front->n;

				p->p = NULL;
				free(his_front->s);
				free(his_front);
				his_front = p;
			} else {
				history_counter++;
			}
		}
	}

	return nr;
}

extern void cmdedit_init(void)
{
	atexit(cmdedit_reset_term);
	signal(SIGINT, prepareToDie);
	signal(SIGQUIT, prepareToDie);
	signal(SIGTERM, prepareToDie);
}
#endif							/* BB_FEATURE_SH_COMMAND_EDITING */