1 This file is read.def, from which is created read.c.
2 It implements the builtin "read" in Bash.
4 Copyright (C) 1987-2010 Free Software Foundation, Inc.
6 This file is part of GNU Bash, the Bourne Again SHell.
8 Bash is free software: you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 3 of the License, or
11 (at your option) any later version.
13 Bash is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with Bash. If not, see <http://www.gnu.org/licenses/>.
24 $FUNCTION read_builtin
25 $SHORT_DOC read [-ers] [-a array] [-d delim] [-i text] [-n nchars] [-N nchars] [-p prompt] [-t timeout] [-u fd] [name ...]
26 Read a line from the standard input and split it into fields.
28 Reads a single line from the standard input, or from file descriptor FD
29 if the -u option is supplied. The line is split into fields as with word
30 splitting, and the first word is assigned to the first NAME, the second
31 word to the second NAME, and so on, with any leftover words assigned to
32 the last NAME. Only the characters found in $IFS are recognized as word
35 If no NAMEs are supplied, the line read is stored in the REPLY variable.
38 -a array assign the words read to sequential indices of the array
39 variable ARRAY, starting at zero
40 -d delim continue until the first character of DELIM is read, rather
42 -e use Readline to obtain the line in an interactive shell
43 -i text Use TEXT as the initial text for Readline
44 -n nchars return after reading NCHARS characters rather than waiting
45 for a newline, but honor a delimiter if fewer than NCHARS
46 characters are read before the delimiter
47 -N nchars return only after reading exactly NCHARS characters, unless
48 EOF is encountered or read times out, ignoring any delimiter
49 -p prompt output the string PROMPT without a trailing newline before
51 -r do not allow backslashes to escape any characters
52 -s do not echo input coming from a terminal
53 -t timeout time out and return failure if a complete line of input is
54 not read withint TIMEOUT seconds. The value of the TMOUT
55 variable is the default timeout. TIMEOUT may be a
56 fractional number. If TIMEOUT is 0, read returns success only
57 if input is available on the specified file descriptor. The
58 exit status is greater than 128 if the timeout is exceeded
59 -u fd read from file descriptor FD instead of the standard input
62 The return code is zero, unless end-of-file is encountered, read times out,
63 or an invalid file descriptor is supplied as the argument to -u.
68 #include "bashtypes.h"
69 #include "posixstat.h"
75 #if defined (HAVE_UNISTD_H)
87 #include "../bashintl.h"
91 #include "bashgetopt.h"
95 #if defined (READLINE)
96 #include "../bashline.h"
97 #include <readline/readline.h>
100 #if defined (BUFFERED_INPUT)
114 #if defined (READLINE)
115 static void reset_attempted_completion_function __P((char *));
116 static int set_itext __P((void));
117 static char *edit_line __P((char *, char *));
118 static void set_eol_delim __P((int));
119 static void reset_eol_delim __P((char *));
121 static SHELL_VAR *bind_read_variable __P((char *, char *));
122 #if defined (HANDLE_MULTIBYTE)
123 static int read_mbchar __P((int, char *, int, int, int));
125 static void ttyrestore __P((struct ttsave *));
127 static sighandler sigalrm __P((int));
128 static void reset_alarm __P((void));
130 static procenv_t alrmbuf;
131 static SigHandler *old_alrm;
132 static unsigned char delim;
138 longjmp (alrmbuf, 1);
144 set_signal_handler (SIGALRM, old_alrm);
148 /* Read the value of the shell variables whose names follow.
149 The reading is done from the current input stream, whatever
150 that may be. Successive words of the input line are assigned
151 to the variables mentioned in LIST. The last variable in LIST
152 gets the remainder of the words on the line. If no variables
153 are mentioned in LIST, then the default variable is $REPLY. */
158 register char *varname;
159 int size, i, nr, pass_next, saw_escape, eof, opt, retval, code, print_ps2;
160 int input_is_tty, input_is_pipe, unbuffered_read, skip_ctlesc, skip_ctlnul;
161 int raw, edit, nchars, silent, have_timeout, ignore_delim, fd;
162 unsigned int tmsec, tmusec;
166 char *input_string, *orig_input_string, *ifs_chars, *prompt, *arrayname;
167 char *e, *t, *t1, *ps2, *tofree;
170 TTYSTRUCT ttattrs, ttset;
171 struct ttsave termsave;
172 #if defined (ARRAY_VARS)
175 #if defined (READLINE)
185 USE_VAR(input_is_pipe);
195 #if defined (READLINE)
203 i = 0; /* Index into the string that we are reading. */
204 raw = edit = 0; /* Not reading raw input by default. */
206 arrayname = prompt = (char *)NULL;
207 fd = 0; /* file descriptor to read from */
209 #if defined (READLINE)
210 rlbuf = itext = (char *)0;
214 tmsec = tmusec = 0; /* no timeout */
215 nr = nchars = input_is_tty = input_is_pipe = unbuffered_read = have_timeout = 0;
216 delim = '\n'; /* read until newline */
219 reset_internal_getopt ();
220 while ((opt = internal_getopt (list, "ersa:d:i:n:p:t:u:N:")) != -1)
228 prompt = list_optarg;
234 #if defined (READLINE)
239 #if defined (READLINE)
243 #if defined (ARRAY_VARS)
245 arrayname = list_optarg;
249 code = uconvert (list_optarg, &ival, &uval);
250 if (code == 0 || ival < 0 || uval < 0)
252 builtin_error (_("%s: invalid timeout specification"), list_optarg);
253 return (EXECUTION_FAILURE);
266 code = legal_number (list_optarg, &intval);
267 if (code == 0 || intval < 0 || intval != (int)intval)
269 sh_invalidnum (list_optarg);
270 return (EXECUTION_FAILURE);
276 code = legal_number (list_optarg, &intval);
277 if (code == 0 || intval < 0 || intval != (int)intval)
279 builtin_error (_("%s: invalid file descriptor specification"), list_optarg);
280 return (EXECUTION_FAILURE);
284 if (sh_validfd (fd) == 0)
286 builtin_error (_("%d: invalid file descriptor: %s"), fd, strerror (errno));
287 return (EXECUTION_FAILURE);
291 delim = *list_optarg;
300 /* `read -t 0 var' tests whether input is available with select/FIONREAD,
301 and fails if those are unavailable */
302 if (have_timeout && tmsec == 0 && tmusec == 0)
304 return (EXECUTION_FAILURE);
306 return (input_avail (fd) ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
309 /* If we're asked to ignore the delimiter, make sure we do. */
313 /* IF IFS is unset, we use the default of " \t\n". */
314 ifs_chars = getifs ();
315 if (ifs_chars == 0) /* XXX - shouldn't happen */
317 /* If we want to read exactly NCHARS chars, don't split on IFS */
320 for (skip_ctlesc = skip_ctlnul = 0, e = ifs_chars; *e; e++)
321 skip_ctlesc |= *e == CTLESC, skip_ctlnul |= *e == CTLNUL;
323 input_string = (char *)xmalloc (size = 112); /* XXX was 128 */
324 input_string[0] = '\0';
326 /* $TMOUT, if set, is the default timeout for read. */
327 if (have_timeout == 0 && (e = get_string_value ("TMOUT")))
329 code = uconvert (e, &ival, &uval);
330 if (code == 0 || ival < 0 || uval < 0)
339 begin_unwind_frame ("read_builtin");
341 #if defined (BUFFERED_INPUT)
342 if (interactive == 0 && default_buffered_input >= 0 && fd_is_bash_input (fd))
343 sync_buffered_stream (default_buffered_input);
346 input_is_tty = isatty (fd);
347 if (input_is_tty == 0)
349 input_is_pipe = (lseek (fd, 0L, SEEK_CUR) < 0) && (errno == ESPIPE);
354 /* If the -p, -e or -s flags were given, but input is not coming from the
355 terminal, turn them off. */
356 if ((prompt || edit || silent) && input_is_tty == 0)
358 prompt = (char *)NULL;
359 #if defined (READLINE)
360 itext = (char *)NULL;
365 #if defined (READLINE)
367 add_unwind_protect (xfree, rlbuf);
370 pass_next = 0; /* Non-zero signifies last char was backslash. */
371 saw_escape = 0; /* Non-zero signifies that we saw an escape char */
373 if (tmsec > 0 || tmusec > 0)
375 /* Turn off the timeout if stdin is a regular file (e.g. from
376 input redirection). */
377 if ((fstat (fd, &tsb) < 0) || S_ISREG (tsb.st_mode))
381 if (tmsec > 0 || tmusec > 0)
383 code = setjmp (alrmbuf);
386 /* Tricky. The top of the unwind-protect stack is the free of
387 input_string. We want to run all the rest and use input_string,
388 so we have to save input_string temporarily, run the unwind-
389 protects, then restore input_string so we can use it later. */
391 input_string[i] = '\0'; /* make sure it's terminated */
394 t = (char *)xmalloc (1);
398 t = savestring (input_string);
400 run_unwind_frame ("read_builtin");
402 retval = 128+SIGALRM;
405 old_alrm = set_signal_handler (SIGALRM, sigalrm);
406 add_unwind_protect (reset_alarm, (char *)NULL);
407 #if defined (READLINE)
409 add_unwind_protect (reset_attempted_completion_function, (char *)NULL);
411 falarm (tmsec, tmusec);
414 /* If we've been asked to read only NCHARS chars, or we're using some
415 character other than newline to terminate the line, do the right
416 thing to readline or the tty. */
417 if (nchars > 0 || delim != '\n')
419 #if defined (READLINE)
424 unwind_protect_int (rl_num_chars_to_read);
425 rl_num_chars_to_read = nchars;
429 set_eol_delim (delim);
430 add_unwind_protect (reset_eol_delim, (char *)NULL);
439 ttgetattr (fd, &ttattrs);
440 termsave.attrs = &ttattrs;
443 i = silent ? ttfd_cbreak (fd, &ttset) : ttfd_onechar (fd, &ttset);
446 add_unwind_protect ((Function *)ttyrestore, (char *)&termsave);
449 else if (silent) /* turn off echo but leave term in canonical mode */
453 ttgetattr (fd, &ttattrs);
454 termsave.attrs = &ttattrs;
457 i = ttfd_noecho (fd, &ttset); /* ttnoecho (); */
461 add_unwind_protect ((Function *)ttyrestore, (char *)&termsave);
464 /* This *must* be the top unwind-protect on the stack, so the manipulation
465 of the unwind-protect stack after the realloc() works right. */
466 add_unwind_protect (xfree, input_string);
467 interrupt_immediately++;
468 terminate_immediately++;
470 unbuffered_read = (nchars > 0) || (delim != '\n') || input_is_pipe;
472 if (prompt && edit == 0)
474 fprintf (stderr, "%s", prompt);
478 #if defined (__CYGWIN__) && defined (O_TEXT)
483 for (print_ps2 = eof = retval = 0;;)
485 #if defined (READLINE)
488 if (rlbuf && rlbuf[rlind] == '\0')
495 rlbuf = edit_line (prompt ? prompt : "", itext);
512 ps2 = get_string_value ("PS2");
513 fprintf (stderr, "%s", ps2 ? ps2 : "");
519 retval = zread (fd, &c, 1);
521 retval = zreadc (fd, &c);
529 #if defined (READLINE)
533 if (i + 4 >= size) /* XXX was i + 2; use i + 4 for multibyte/read_mbchar */
535 input_string = (char *)xrealloc (input_string, size += 128);
536 remove_unwind_protect ();
537 add_unwind_protect (xfree, input_string);
540 /* If the next character is to be accepted verbatim, a backslash
541 newline pair still disappears from the input. */
547 i--; /* back up over the CTLESC */
548 if (interactive && input_is_tty && raw == 0)
556 /* This may cause problems if IFS contains CTLESC */
557 if (c == '\\' && raw == 0)
560 if (skip_ctlesc == 0)
563 input_string[i++] = CTLESC;
568 if ((unsigned char)c == delim)
571 if ((skip_ctlesc == 0 && c == CTLESC) || (skip_ctlnul == 0 && c == CTLNUL))
574 input_string[i++] = CTLESC;
578 input_string[i++] = c;
580 #if defined (HANDLE_MULTIBYTE)
581 if (nchars > 0 && MB_CUR_MAX > 1)
583 input_string[i] = '\0'; /* for simplicity and debugging */
584 i += read_mbchar (fd, input_string, i, c, unbuffered_read);
590 if (nchars > 0 && nr >= nchars)
593 input_string[i] = '\0';
598 builtin_error (_("read error: %d: %s"), fd, strerror (errno));
599 run_unwind_frame ("read_builtin");
600 return (EXECUTION_FAILURE);
604 if (tmsec > 0 || tmusec > 0)
607 if (nchars > 0 || delim != '\n')
609 #if defined (READLINE)
613 rl_num_chars_to_read = 0;
615 reset_eol_delim ((char *)NULL);
620 ttyrestore (&termsave);
623 ttyrestore (&termsave);
625 if (unbuffered_read == 0)
628 discard_unwind_frame ("read_builtin");
630 retval = eof ? EXECUTION_FAILURE : EXECUTION_SUCCESS;
634 interrupt_immediately--;
635 terminate_immediately--;
637 #if defined (ARRAY_VARS)
638 /* If -a was given, take the string read, break it into a list of words,
639 an assign them to `arrayname' in turn. */
642 if (legal_identifier (arrayname) == 0)
644 sh_invalidid (arrayname);
645 xfree (input_string);
646 return (EXECUTION_FAILURE);
649 var = find_or_make_array_variable (arrayname, 1);
652 xfree (input_string);
653 return EXECUTION_FAILURE; /* readonly or noassign */
657 builtin_error (_("%s: cannot convert associative to indexed array"), arrayname);
658 xfree (input_string);
659 return EXECUTION_FAILURE; /* existing associative array */
661 array_flush (array_cell (var));
663 alist = list_string (input_string, ifs_chars, 0);
667 dequote_list (alist);
669 word_list_remove_quoted_nulls (alist);
670 assign_array_var_from_word_list (var, alist, 0);
671 dispose_words (alist);
673 xfree (input_string);
676 #endif /* ARRAY_VARS */
678 /* If there are no variables, save the text of the line read to the
679 variable $REPLY. ksh93 strips leading and trailing IFS whitespace,
680 so that `read x ; echo "$x"' and `read ; echo "$REPLY"' behave the
681 same way, but I believe that the difference in behaviors is useful
682 enough to not do it. Without the bash behavior, there is no way
683 to read a line completely without interpretation or modification
684 unless you mess with $IFS (e.g., setting it to the empty string).
685 If you disagree, change the occurrences of `#if 0' to `#if 1' below. */
689 orig_input_string = input_string;
690 for (t = input_string; ifs_chars && *ifs_chars && spctabnl(*t) && isifs(*t); t++)
693 input_string = strip_trailing_ifs_whitespace (input_string, ifs_chars, saw_escape);
698 t = dequote_string (input_string);
699 var = bind_variable ("REPLY", t, 0);
703 var = bind_variable ("REPLY", input_string, 0);
704 VUNSETATTR (var, att_invisible);
710 /* This code implements the Posix.2 spec for splitting the words
711 read and assigning them to variables. */
712 orig_input_string = input_string;
714 /* Remove IFS white space at the beginning of the input string. If
715 $IFS is null, no field splitting is performed. */
716 for (t = input_string; ifs_chars && *ifs_chars && spctabnl(*t) && isifs(*t); t++)
719 for (; list->next; list = list->next)
721 varname = list->word->word;
722 #if defined (ARRAY_VARS)
723 if (legal_identifier (varname) == 0 && valid_array_reference (varname) == 0)
725 if (legal_identifier (varname) == 0)
728 sh_invalidid (varname);
729 xfree (orig_input_string);
730 return (EXECUTION_FAILURE);
733 /* If there are more variables than words read from the input,
734 the remaining variables are set to the empty string. */
737 /* This call updates INPUT_STRING. */
738 t = get_word_from_string (&input_string, ifs_chars, &e);
741 /* Don't bother to remove the CTLESC unless we added one
742 somewhere while reading the string. */
745 t1 = dequote_string (t);
746 var = bind_read_variable (varname, t1);
750 var = bind_read_variable (varname, t ? t : "");
755 var = bind_read_variable (varname, "");
761 xfree (orig_input_string);
762 return (EXECUTION_FAILURE);
765 stupidly_hack_special_variables (varname);
766 VUNSETATTR (var, att_invisible);
769 /* Now assign the rest of the line to the last variable argument. */
770 #if defined (ARRAY_VARS)
771 if (legal_identifier (list->word->word) == 0 && valid_array_reference (list->word->word) == 0)
773 if (legal_identifier (list->word->word) == 0)
776 sh_invalidid (list->word->word);
777 xfree (orig_input_string);
778 return (EXECUTION_FAILURE);
782 /* This has to be done this way rather than using string_list
783 and list_string because Posix.2 says that the last variable gets the
784 remaining words and their intervening separators. */
785 input_string = strip_trailing_ifs_whitespace (input_string, ifs_chars, saw_escape);
787 /* Check whether or not the number of fields is exactly the same as the
788 number of variables. */
793 t = get_word_from_string (&input_string, ifs_chars, &e);
794 if (*input_string == 0)
795 tofree = input_string = t;
798 input_string = strip_trailing_ifs_whitespace (t1, ifs_chars, saw_escape);
804 if (saw_escape && input_string && *input_string)
806 t = dequote_string (input_string);
807 var = bind_read_variable (list->word->word, t);
811 var = bind_read_variable (list->word->word, input_string ? input_string : "");
815 stupidly_hack_special_variables (list->word->word);
816 VUNSETATTR (var, att_invisible);
819 retval = EXECUTION_FAILURE;
822 xfree (orig_input_string);
828 bind_read_variable (name, value)
832 #if defined (ARRAY_VARS)
833 if (valid_array_reference (name) == 0)
834 v = bind_variable (name, value, 0);
836 v = assign_array_element (name, value, 0);
837 #else /* !ARRAY_VARS */
838 v = bind_variable (name, value, 0);
839 #endif /* !ARRAY_VARS */
841 : ((readonly_p (v) || noassign_p (v)) ? (SHELL_VAR *)NULL : v));
844 #if defined (HANDLE_MULTIBYTE)
846 read_mbchar (fd, string, ind, ch, unbuffered)
849 int ind, ch, unbuffered;
851 char mbchar[MB_LEN_MAX + 1];
855 mbstate_t ps, ps_back;
858 memset (&ps, '\0', sizeof (mbstate_t));
859 memset (&ps_back, '\0', sizeof (mbstate_t));
863 for (n = 0; n <= MB_LEN_MAX; n++)
866 ret = mbrtowc (&wc, mbchar, i, &ps);
867 if (ret == (size_t)-2)
871 r = zread (fd, &c, 1);
879 else if (ret == (size_t)-1 || ret == (size_t)0 || ret > (size_t)0)
884 if (i > 1) /* read a multibyte char */
885 /* mbchar[0] is already string[ind-1] */
886 for (r = 1; r < i; r++)
887 string[ind+r-1] = mbchar[r];
897 ttsetattr (ttp->fd, ttp->attrs);
900 #if defined (READLINE)
901 static rl_completion_func_t *old_attempted_completion_function = 0;
902 static rl_hook_func_t *old_startup_hook;
903 static char *deftext;
906 reset_attempted_completion_function (cp)
909 if (rl_attempted_completion_function == 0 && old_attempted_completion_function)
910 rl_attempted_completion_function = old_attempted_completion_function;
919 if (old_startup_hook)
920 r1 = (*old_startup_hook) ();
923 r2 = rl_insert_text (deftext);
924 deftext = (char *)NULL;
925 rl_startup_hook = old_startup_hook;
926 old_startup_hook = (rl_hook_func_t *)NULL;
939 if (bash_readline_initialized == 0)
940 initialize_readline ();
942 old_attempted_completion_function = rl_attempted_completion_function;
943 rl_attempted_completion_function = (rl_completion_func_t *)NULL;
946 old_startup_hook = rl_startup_hook;
947 rl_startup_hook = set_itext;
951 rl_attempted_completion_function = old_attempted_completion_function;
952 old_attempted_completion_function = (rl_completion_func_t *)NULL;
957 ret = (char *)xrealloc (ret, len + 2);
963 static int old_delim_ctype;
964 static rl_command_func_t *old_delim_func;
965 static int old_newline_ctype;
966 static rl_command_func_t *old_newline_func;
968 static unsigned char delim_char;
976 if (bash_readline_initialized == 0)
977 initialize_readline ();
978 cmap = rl_get_keymap ();
980 /* Change newline to self-insert */
981 old_newline_ctype = cmap[RETURN].type;
982 old_newline_func = cmap[RETURN].function;
983 cmap[RETURN].type = ISFUNC;
984 cmap[RETURN].function = rl_insert;
986 /* Bind the delimiter character to accept-line. */
987 old_delim_ctype = cmap[c].type;
988 old_delim_func = cmap[c].function;
989 cmap[c].type = ISFUNC;
990 cmap[c].function = rl_newline;
1001 cmap = rl_get_keymap ();
1003 cmap[RETURN].type = old_newline_ctype;
1004 cmap[RETURN].function = old_newline_func;
1006 cmap[delim_char].type = old_delim_ctype;
1007 cmap[delim_char].function = old_delim_func;