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Fix a bug that allowed a tracing process (e.g. gdb) to write
[FreeBSD/releng/9.1.git] / lib / libedit / read.c
1 /*-
2  * Copyright (c) 1992, 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  * Christos Zoulas of Cornell University.
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  *      $NetBSD: read.c,v 1.52 2009/07/22 15:57:00 christos Exp $
33  */
34
35 #if !defined(lint) && !defined(SCCSID)
36 static char sccsid[] = "@(#)read.c      8.1 (Berkeley) 6/4/93";
37 #endif /* not lint && not SCCSID */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 /*
42  * read.c: Clean this junk up! This is horrible code.
43  *         Terminal read functions
44  */
45 #include "sys.h"
46 #include <errno.h>
47 #include <fcntl.h>
48 #include <unistd.h>
49 #include <stdlib.h>
50 #include "el.h"
51
52 #define OKCMD   -1
53
54 private int     read__fixio(int, int);
55 private int     read_preread(EditLine *);
56 private int     read_char(EditLine *, char *);
57 private int     read_getcmd(EditLine *, el_action_t *, char *);
58 private void    read_pop(c_macro_t *);
59
60 /* read_init():
61  *      Initialize the read stuff
62  */
63 protected int
64 read_init(EditLine *el)
65 {
66         /* builtin read_char */
67         el->el_read.read_char = read_char;
68         return 0;
69 }
70
71
72 /* el_read_setfn():
73  *      Set the read char function to the one provided.
74  *      If it is set to EL_BUILTIN_GETCFN, then reset to the builtin one.
75  */
76 protected int
77 el_read_setfn(EditLine *el, el_rfunc_t rc)
78 {
79         el->el_read.read_char = (rc == EL_BUILTIN_GETCFN) ? read_char : rc;
80         return 0;
81 }
82
83
84 /* el_read_getfn():
85  *      return the current read char function, or EL_BUILTIN_GETCFN
86  *      if it is the default one
87  */
88 protected el_rfunc_t
89 el_read_getfn(EditLine *el)
90 {
91        return (el->el_read.read_char == read_char) ?
92             EL_BUILTIN_GETCFN : el->el_read.read_char;
93 }
94
95
96 #ifndef MIN
97 #define MIN(A,B) ((A) < (B) ? (A) : (B))
98 #endif
99
100 #ifdef DEBUG_EDIT
101 private void
102 read_debug(EditLine *el)
103 {
104
105         if (el->el_line.cursor > el->el_line.lastchar)
106                 (void) fprintf(el->el_errfile, "cursor > lastchar\r\n");
107         if (el->el_line.cursor < el->el_line.buffer)
108                 (void) fprintf(el->el_errfile, "cursor < buffer\r\n");
109         if (el->el_line.cursor > el->el_line.limit)
110                 (void) fprintf(el->el_errfile, "cursor > limit\r\n");
111         if (el->el_line.lastchar > el->el_line.limit)
112                 (void) fprintf(el->el_errfile, "lastchar > limit\r\n");
113         if (el->el_line.limit != &el->el_line.buffer[EL_BUFSIZ - 2])
114                 (void) fprintf(el->el_errfile, "limit != &buffer[EL_BUFSIZ-2]\r\n");
115 }
116 #endif /* DEBUG_EDIT */
117
118
119 /* read__fixio():
120  *      Try to recover from a read error
121  */
122 /* ARGSUSED */
123 private int
124 read__fixio(int fd __unused, int e)
125 {
126
127         switch (e) {
128         case -1:                /* Make sure that the code is reachable */
129
130 #ifdef EWOULDBLOCK
131         case EWOULDBLOCK:
132 #ifndef TRY_AGAIN
133 #define TRY_AGAIN
134 #endif
135 #endif /* EWOULDBLOCK */
136
137 #if defined(POSIX) && defined(EAGAIN)
138 #if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
139         case EAGAIN:
140 #ifndef TRY_AGAIN
141 #define TRY_AGAIN
142 #endif
143 #endif /* EWOULDBLOCK && EWOULDBLOCK != EAGAIN */
144 #endif /* POSIX && EAGAIN */
145
146                 e = 0;
147 #ifdef TRY_AGAIN
148 #if defined(F_SETFL) && defined(O_NDELAY)
149                 if ((e = fcntl(fd, F_GETFL, 0)) == -1)
150                         return (-1);
151
152                 if (fcntl(fd, F_SETFL, e & ~O_NDELAY) == -1)
153                         return (-1);
154                 else
155                         e = 1;
156 #endif /* F_SETFL && O_NDELAY */
157
158 #ifdef FIONBIO
159                 {
160                         int zero = 0;
161
162                         if (ioctl(fd, FIONBIO, (ioctl_t) & zero) == -1)
163                                 return (-1);
164                         else
165                                 e = 1;
166                 }
167 #endif /* FIONBIO */
168
169 #endif /* TRY_AGAIN */
170                 return (e ? 0 : -1);
171
172         case EINTR:
173                 return (0);
174
175         default:
176                 return (-1);
177         }
178 }
179
180
181 /* read_preread():
182  *      Try to read the stuff in the input queue;
183  */
184 private int
185 read_preread(EditLine *el)
186 {
187         int chrs = 0;
188
189         if (el->el_tty.t_mode == ED_IO)
190                 return (0);
191
192 #ifdef FIONREAD
193         (void) ioctl(el->el_infd, FIONREAD, (ioctl_t) & chrs);
194         if (chrs > 0) {
195                 char buf[EL_BUFSIZ];
196
197                 chrs = read(el->el_infd, buf,
198                     (size_t) MIN(chrs, EL_BUFSIZ - 1));
199                 if (chrs > 0) {
200                         buf[chrs] = '\0';
201                         el_push(el, buf);
202                 }
203         }
204 #endif /* FIONREAD */
205
206         return (chrs > 0);
207 }
208
209
210 /* el_push():
211  *      Push a macro
212  */
213 public void
214 el_push(EditLine *el, const char *str)
215 {
216         c_macro_t *ma = &el->el_chared.c_macro;
217
218         if (str != NULL && ma->level + 1 < EL_MAXMACRO) {
219                 ma->level++;
220                 if ((ma->macro[ma->level] = el_strdup(str)) != NULL)
221                         return;
222                 ma->level--;
223         }
224         term_beep(el);
225         term__flush(el);
226 }
227
228
229 /* read_getcmd():
230  *      Return next command from the input stream.
231  */
232 private int
233 read_getcmd(EditLine *el, el_action_t *cmdnum, char *ch)
234 {
235         el_action_t cmd;
236         int num;
237
238         do {
239                 if ((num = el_getc(el, ch)) != 1)       /* if EOF or error */
240                         return (num);
241
242 #ifdef  KANJI
243                 if ((*ch & 0200)) {
244                         el->el_state.metanext = 0;
245                         cmd = CcViMap[' '];
246                         break;
247                 } else
248 #endif /* KANJI */
249
250                 if (el->el_state.metanext) {
251                         el->el_state.metanext = 0;
252                         *ch |= 0200;
253                 }
254                 cmd = el->el_map.current[(unsigned char) *ch];
255                 if (cmd == ED_SEQUENCE_LEAD_IN) {
256                         key_value_t val;
257                         switch (key_get(el, ch, &val)) {
258                         case XK_CMD:
259                                 cmd = val.cmd;
260                                 break;
261                         case XK_STR:
262                                 el_push(el, val.str);
263                                 break;
264 #ifdef notyet
265                         case XK_EXE:
266                                 /* XXX: In the future to run a user function */
267                                 RunCommand(val.str);
268                                 break;
269 #endif
270                         default:
271                                 EL_ABORT((el->el_errfile, "Bad XK_ type \n"));
272                                 break;
273                         }
274                 }
275                 if (el->el_map.alt == NULL)
276                         el->el_map.current = el->el_map.key;
277         } while (cmd == ED_SEQUENCE_LEAD_IN);
278         *cmdnum = cmd;
279         return (OKCMD);
280 }
281
282
283 /* read_char():
284  *      Read a character from the tty.
285  */
286 private int
287 read_char(EditLine *el, char *cp)
288 {
289         ssize_t num_read;
290         int tried = 0;
291
292         while ((num_read = read(el->el_infd, cp, 1)) == -1)
293                 if (!tried && read__fixio(el->el_infd, errno) == 0)
294                         tried = 1;
295                 else {
296                         *cp = '\0';
297                         return (-1);
298                 }
299
300         return (int)num_read;
301 }
302
303 /* read_pop():
304  *      Pop a macro from the stack
305  */
306 private void
307 read_pop(c_macro_t *ma)
308 {
309         int i;
310
311         el_free(ma->macro[0]);
312         for (i = 0; i < ma->level; i++)
313                 ma->macro[i] = ma->macro[i + 1];
314         ma->level--;
315         ma->offset = 0;
316 }
317
318 /* el_getc():
319  *      Read a character
320  */
321 public int
322 el_getc(EditLine *el, char *cp)
323 {
324         int num_read;
325         c_macro_t *ma = &el->el_chared.c_macro;
326
327         term__flush(el);
328         for (;;) {
329                 if (ma->level < 0) {
330                         if (!read_preread(el))
331                                 break;
332                 }
333
334                 if (ma->level < 0)
335                         break;
336
337                 if (ma->macro[0][ma->offset] == '\0') {
338                         read_pop(ma);
339                         continue;
340                 }
341
342                 *cp = ma->macro[0][ma->offset++] & 0377;
343
344                 if (ma->macro[0][ma->offset] == '\0') {
345                         /* Needed for QuoteMode On */
346                         read_pop(ma);
347                 }
348
349                 return (1);
350         }
351
352 #ifdef DEBUG_READ
353         (void) fprintf(el->el_errfile, "Turning raw mode on\n");
354 #endif /* DEBUG_READ */
355         if (tty_rawmode(el) < 0)/* make sure the tty is set up correctly */
356                 return (0);
357
358 #ifdef DEBUG_READ
359         (void) fprintf(el->el_errfile, "Reading a character\n");
360 #endif /* DEBUG_READ */
361         num_read = (*el->el_read.read_char)(el, cp);
362 #ifdef DEBUG_READ
363         (void) fprintf(el->el_errfile, "Got it %c\n", *cp);
364 #endif /* DEBUG_READ */
365         return (num_read);
366 }
367
368 protected void
369 read_prepare(EditLine *el)
370 {
371         if (el->el_flags & HANDLE_SIGNALS)
372                 sig_set(el);
373         if (el->el_flags & NO_TTY)
374                 return;
375         if ((el->el_flags & (UNBUFFERED|EDIT_DISABLED)) == UNBUFFERED)
376                 tty_rawmode(el);
377
378         /* This is relatively cheap, and things go terribly wrong if
379            we have the wrong size. */
380         el_resize(el);
381         re_clear_display(el);   /* reset the display stuff */
382         ch_reset(el, 0);
383         re_refresh(el);         /* print the prompt */
384
385         if (el->el_flags & UNBUFFERED)
386                 term__flush(el);
387 }
388
389 protected void
390 read_finish(EditLine *el)
391 {
392         if ((el->el_flags & UNBUFFERED) == 0)
393                 (void) tty_cookedmode(el);
394         if (el->el_flags & HANDLE_SIGNALS)
395                 sig_clr(el);
396 }
397
398 public const char *
399 el_gets(EditLine *el, int *nread)
400 {
401         int retval;
402         el_action_t cmdnum = 0;
403         int num;                /* how many chars we have read at NL */
404         char ch;
405         int crlf = 0;
406 #ifdef FIONREAD
407         c_macro_t *ma = &el->el_chared.c_macro;
408 #endif /* FIONREAD */
409
410         *nread = 0;
411
412         if (el->el_flags & NO_TTY) {
413                 char *cp = el->el_line.buffer;
414                 size_t idx;
415
416                 while ((*el->el_read.read_char)(el, cp) == 1) {
417                         /* make sure there is space for next character */
418                         if (cp + 1 >= el->el_line.limit) {
419                                 idx = (cp - el->el_line.buffer);
420                                 if (!ch_enlargebufs(el, 2))
421                                         break;
422                                 cp = &el->el_line.buffer[idx];
423                         }
424                         cp++;
425                         if (el->el_flags & UNBUFFERED)
426                                 break;
427                         if (cp[-1] == '\r' || cp[-1] == '\n')
428                                 break;
429                 }
430
431                 el->el_line.cursor = el->el_line.lastchar = cp;
432                 *cp = '\0';
433                 if (nread)
434                         *nread = (int)(el->el_line.cursor - el->el_line.buffer);
435                 return (*nread ? el->el_line.buffer : NULL);
436         }
437
438
439 #ifdef FIONREAD
440         if (el->el_tty.t_mode == EX_IO && ma->level < 0) {
441                 long chrs = 0;
442
443                 (void) ioctl(el->el_infd, FIONREAD, (ioctl_t) & chrs);
444                 if (chrs == 0) {
445                         if (tty_rawmode(el) < 0) {
446                                 if (nread)
447                                         *nread = 0;
448                                 return (NULL);
449                         }
450                 }
451         }
452 #endif /* FIONREAD */
453
454         if ((el->el_flags & UNBUFFERED) == 0)
455                 read_prepare(el);
456
457         if (el->el_flags & EDIT_DISABLED) {
458                 char *cp;
459                 size_t idx;
460                 if ((el->el_flags & UNBUFFERED) == 0)
461                         cp = el->el_line.buffer;
462                 else
463                         cp = el->el_line.lastchar;
464
465                 term__flush(el);
466
467                 while ((*el->el_read.read_char)(el, cp) == 1) {
468                         /* make sure there is space next character */
469                         if (cp + 1 >= el->el_line.limit) {
470                                 idx = (cp - el->el_line.buffer);
471                                 if (!ch_enlargebufs(el, 2))
472                                         break;
473                                 cp = &el->el_line.buffer[idx];
474                         }
475                         cp++;
476                         crlf = cp[-1] == '\r' || cp[-1] == '\n';
477                         if (el->el_flags & UNBUFFERED)
478                                 break;
479                         if (crlf)
480                                 break;
481                 }
482
483                 el->el_line.cursor = el->el_line.lastchar = cp;
484                 *cp = '\0';
485                 if (nread)
486                         *nread = (int)(el->el_line.cursor - el->el_line.buffer);
487                 return (*nread ? el->el_line.buffer : NULL);
488         }
489
490         for (num = OKCMD; num == OKCMD;) {      /* while still editing this
491                                                  * line */
492 #ifdef DEBUG_EDIT
493                 read_debug(el);
494 #endif /* DEBUG_EDIT */
495                 /* if EOF or error */
496                 if ((num = read_getcmd(el, &cmdnum, &ch)) != OKCMD) {
497 #ifdef DEBUG_READ
498                         (void) fprintf(el->el_errfile,
499                             "Returning from el_gets %d\n", num);
500 #endif /* DEBUG_READ */
501                         break;
502                 }
503                 if ((unsigned int)cmdnum >= (unsigned int)el->el_map.nfunc) {   /* BUG CHECK command */
504 #ifdef DEBUG_EDIT
505                         (void) fprintf(el->el_errfile,
506                             "ERROR: illegal command from key 0%o\r\n", ch);
507 #endif /* DEBUG_EDIT */
508                         continue;       /* try again */
509                 }
510                 /* now do the real command */
511 #ifdef DEBUG_READ
512                 {
513                         el_bindings_t *b;
514                         for (b = el->el_map.help; b->name; b++)
515                                 if (b->func == cmdnum)
516                                         break;
517                         if (b->name)
518                                 (void) fprintf(el->el_errfile,
519                                     "Executing %s\n", b->name);
520                         else
521                                 (void) fprintf(el->el_errfile,
522                                     "Error command = %d\n", cmdnum);
523                 }
524 #endif /* DEBUG_READ */
525                 /* vi redo needs these way down the levels... */
526                 el->el_state.thiscmd = cmdnum;
527                 el->el_state.thisch = ch;
528                 if (el->el_map.type == MAP_VI &&
529                     el->el_map.current == el->el_map.key &&
530                     el->el_chared.c_redo.pos < el->el_chared.c_redo.lim) {
531                         if (cmdnum == VI_DELETE_PREV_CHAR &&
532                             el->el_chared.c_redo.pos != el->el_chared.c_redo.buf
533                             && isprint((unsigned char)el->el_chared.c_redo.pos[-1]))
534                                 el->el_chared.c_redo.pos--;
535                         else
536                                 *el->el_chared.c_redo.pos++ = ch;
537                 }
538                 retval = (*el->el_map.func[cmdnum]) (el, ch);
539 #ifdef DEBUG_READ
540                 (void) fprintf(el->el_errfile,
541                         "Returned state %d\n", retval );
542 #endif /* DEBUG_READ */
543
544                 /* save the last command here */
545                 el->el_state.lastcmd = cmdnum;
546
547                 /* use any return value */
548                 switch (retval) {
549                 case CC_CURSOR:
550                         re_refresh_cursor(el);
551                         break;
552
553                 case CC_REDISPLAY:
554                         re_clear_lines(el);
555                         re_clear_display(el);
556                         /* FALLTHROUGH */
557
558                 case CC_REFRESH:
559                         re_refresh(el);
560                         break;
561
562                 case CC_REFRESH_BEEP:
563                         re_refresh(el);
564                         term_beep(el);
565                         break;
566
567                 case CC_NORM:   /* normal char */
568                         break;
569
570                 case CC_ARGHACK:        /* Suggested by Rich Salz */
571                         /* <rsalz@pineapple.bbn.com> */
572                         continue;       /* keep going... */
573
574                 case CC_EOF:    /* end of file typed */
575                         if ((el->el_flags & UNBUFFERED) == 0)
576                                 num = 0;
577                         else if (num == -1) {
578                                 *el->el_line.lastchar++ = CONTROL('d');
579                                 el->el_line.cursor = el->el_line.lastchar;
580                                 num = 1;
581                         }
582                         break;
583
584                 case CC_NEWLINE:        /* normal end of line */
585                         num = (int)(el->el_line.lastchar - el->el_line.buffer);
586                         break;
587
588                 case CC_FATAL:  /* fatal error, reset to known state */
589 #ifdef DEBUG_READ
590                         (void) fprintf(el->el_errfile,
591                             "*** editor fatal ERROR ***\r\n\n");
592 #endif /* DEBUG_READ */
593                         /* put (real) cursor in a known place */
594                         re_clear_display(el);   /* reset the display stuff */
595                         ch_reset(el, 1);        /* reset the input pointers */
596                         re_refresh(el); /* print the prompt again */
597                         break;
598
599                 case CC_ERROR:
600                 default:        /* functions we don't know about */
601 #ifdef DEBUG_READ
602                         (void) fprintf(el->el_errfile,
603                             "*** editor ERROR ***\r\n\n");
604 #endif /* DEBUG_READ */
605                         term_beep(el);
606                         term__flush(el);
607                         break;
608                 }
609                 el->el_state.argument = 1;
610                 el->el_state.doingarg = 0;
611                 el->el_chared.c_vcmd.action = NOP;
612                 if (el->el_flags & UNBUFFERED)
613                         break;
614         }
615
616         term__flush(el);                /* flush any buffered output */
617         /* make sure the tty is set up correctly */
618         if ((el->el_flags & UNBUFFERED) == 0) {
619                 read_finish(el);
620                 if (nread)
621                         *nread = num;
622         } else {
623                 if (nread)
624                         *nread =
625                             (int)(el->el_line.lastchar - el->el_line.buffer);
626         }
627         return (num ? el->el_line.buffer : NULL);
628 }