read.def

android-w.song.android.widget

This file is read.def, from which is created read.c.
It implements the builtin "read" in Bash.

Copyright (C) 1987-2010 Free Software Foundation, Inc.

This file is part of GNU Bash, the Bourne Again SHell.

Bash is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Bash is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Bash.  If not, see <http://www.gnu.org/licenses/>.

$PRODUCES read.c

$BUILTIN read
$FUNCTION read_builtin
$SHORT_DOC read [-ers] [-a array] [-d delim] [-i text] [-n nchars] [-N nchars] [-p prompt] [-t timeout] [-u fd] [name ...]
Read a line from the standard input and split it into fields.

Reads a single line from the standard input, or from file descriptor FD
if the -u option is supplied.  The line is split into fields as with word
splitting, and the first word is assigned to the first NAME, the second
word to the second NAME, and so on, with any leftover words assigned to
the last NAME.  Only the characters found in $IFS are recognized as word
delimiters.

If no NAMEs are supplied, the line read is stored in the REPLY variable.

Options:
  -a array	assign the words read to sequential indices of the array
		variable ARRAY, starting at zero
  -d delim	continue until the first character of DELIM is read, rather
		than newline
  -e		use Readline to obtain the line in an interactive shell
  -i text	Use TEXT as the initial text for Readline
  -n nchars	return after reading NCHARS characters rather than waiting
		for a newline, but honor a delimiter if fewer than NCHARS
		characters are read before the delimiter
  -N nchars	return only after reading exactly NCHARS characters, unless
		EOF is encountered or read times out, ignoring any delimiter
  -p prompt	output the string PROMPT without a trailing newline before
		attempting to read
  -r		do not allow backslashes to escape any characters
  -s		do not echo input coming from a terminal
  -t timeout	time out and return failure if a complete line of input is
		not read withint TIMEOUT seconds.  The value of the TMOUT
		variable is the default timeout.  TIMEOUT may be a
		fractional number.  If TIMEOUT is 0, read returns success only
		if input is available on the specified file descriptor.  The
		exit status is greater than 128 if the timeout is exceeded
  -u fd		read from file descriptor FD instead of the standard input

Exit Status:
The return code is zero, unless end-of-file is encountered, read times out,
or an invalid file descriptor is supplied as the argument to -u.
$END

#include <config.h>

#include "bashtypes.h"
#include "posixstat.h"

#include <stdio.h>

#include "bashansi.h"

#if defined (HAVE_UNISTD_H)
#  include <unistd.h>
#endif

#include <signal.h>
#include <errno.h>

#ifdef __CYGWIN__
#  include <fcntl.h>
#  include <io.h>
#endif

#include "../bashintl.h"

#include "../shell.h"
#include "common.h"
#include "bashgetopt.h"

#include <shtty.h>

#if defined (READLINE)
#include "../bashline.h"
#include <readline/readline.h>
#endif

#if defined (BUFFERED_INPUT)
#  include "input.h"
#endif

#if !defined(errno)
extern int errno;
#endif

struct ttsave
{
  int fd;
  TTYSTRUCT *attrs;
};

#if defined (READLINE)
static void reset_attempted_completion_function __P((char *));
static int set_itext __P((void));
static char *edit_line __P((char *, char *));
static void set_eol_delim __P((int));
static void reset_eol_delim __P((char *));
#endif
static SHELL_VAR *bind_read_variable __P((char *, char *));
#if defined (HANDLE_MULTIBYTE)
static int read_mbchar __P((int, char *, int, int, int));
#endif
static void ttyrestore __P((struct ttsave *));

static sighandler sigalrm __P((int));
static void reset_alarm __P((void));

static procenv_t alrmbuf;
static SigHandler *old_alrm;
static unsigned char delim;

static sighandler
sigalrm (s)
     int s;
{
  longjmp (alrmbuf, 1);
}

static void
reset_alarm ()
{
  set_signal_handler (SIGALRM, old_alrm);
  falarm (0, 0);
}

/* Read the value of the shell variables whose names follow.
   The reading is done from the current input stream, whatever
   that may be.  Successive words of the input line are assigned
   to the variables mentioned in LIST.  The last variable in LIST
   gets the remainder of the words on the line.  If no variables
   are mentioned in LIST, then the default variable is $REPLY. */
int
read_builtin (list)
     WORD_LIST *list;
{
  register char *varname;
  int size, i, nr, pass_next, saw_escape, eof, opt, retval, code, print_ps2;
  int input_is_tty, input_is_pipe, unbuffered_read, skip_ctlesc, skip_ctlnul;
  int raw, edit, nchars, silent, have_timeout, ignore_delim, fd;
  unsigned int tmsec, tmusec;
  long ival, uval;
  intmax_t intval;
  char c;
  char *input_string, *orig_input_string, *ifs_chars, *prompt, *arrayname;
  char *e, *t, *t1, *ps2, *tofree;
  struct stat tsb;
  SHELL_VAR *var;
  TTYSTRUCT ttattrs, ttset;
  struct ttsave termsave;
#if defined (ARRAY_VARS)
  WORD_LIST *alist;
#endif
#if defined (READLINE)
  char *rlbuf, *itext;
  int rlind;
#endif

  USE_VAR(size);
  USE_VAR(i);
  USE_VAR(pass_next);
  USE_VAR(print_ps2);
  USE_VAR(saw_escape);
  USE_VAR(input_is_pipe);
/*  USE_VAR(raw); */
  USE_VAR(edit);
  USE_VAR(tmsec);
  USE_VAR(tmusec);
  USE_VAR(nchars);
  USE_VAR(silent);
  USE_VAR(ifs_chars);
  USE_VAR(prompt);
  USE_VAR(arrayname);
#if defined (READLINE)
  USE_VAR(rlbuf);
  USE_VAR(rlind);
  USE_VAR(itext);
#endif
  USE_VAR(list);
  USE_VAR(ps2);

  i = 0;		/* Index into the string that we are reading. */
  raw = edit = 0;	/* Not reading raw input by default. */
  silent = 0;
  arrayname = prompt = (char *)NULL;
  fd = 0;		/* file descriptor to read from */

#if defined (READLINE)
  rlbuf = itext = (char *)0;
  rlind = 0;
#endif

  tmsec = tmusec = 0;		/* no timeout */
  nr = nchars = input_is_tty = input_is_pipe = unbuffered_read = have_timeout = 0;
  delim = '\n';		/* read until newline */
  ignore_delim = 0;

  reset_internal_getopt ();
  while ((opt = internal_getopt (list, "ersa:d:i:n:p:t:u:N:")) != -1)
    {
      switch (opt)
	{
	case 'r':
	  raw = 1;
	  break;
	case 'p':
	  prompt = list_optarg;
	  break;
	case 's':
	  silent = 1;
	  break;
	case 'e':
#if defined (READLINE)
	  edit = 1;
#endif
	  break;
	case 'i':
#if defined (READLINE)
	  itext = list_optarg;
#endif
	  break;
#if defined (ARRAY_VARS)
	case 'a':
	  arrayname = list_optarg;
	  break;
#endif
	case 't':
	  code = uconvert (list_optarg, &ival, &uval);
	  if (code == 0 || ival < 0 || uval < 0)
	    {
	      builtin_error (_("%s: invalid timeout specification"), list_optarg);
	      return (EXECUTION_FAILURE);
	    }
	  else
	    {
	      have_timeout = 1;
	      tmsec = ival;
	      tmusec = uval;
	    }
	  break;
	case 'N':
	  ignore_delim = 1;
	  delim = -1;
	case 'n':
	  code = legal_number (list_optarg, &intval);
	  if (code == 0 || intval < 0 || intval != (int)intval)
	    {
	      sh_invalidnum (list_optarg);
	      return (EXECUTION_FAILURE);
	    }
	  else
	    nchars = intval;
	  break;
	case 'u':
	  code = legal_number (list_optarg, &intval);
	  if (code == 0 || intval < 0 || intval != (int)intval)
	    {
	      builtin_error (_("%s: invalid file descriptor specification"), list_optarg);
	      return (EXECUTION_FAILURE);
	    }
	  else
	    fd = intval;
	  if (sh_validfd (fd) == 0)
	    {
	      builtin_error (_("%d: invalid file descriptor: %s"), fd, strerror (errno));
	      return (EXECUTION_FAILURE);
	    }
	  break;
	case 'd':
	  delim = *list_optarg;
	  break;
	default:
	  builtin_usage ();
	  return (EX_USAGE);
	}
    }
  list = loptend;

  /* `read -t 0 var' tests whether input is available with select/FIONREAD,
     and fails if those are unavailable */
  if (have_timeout && tmsec == 0 && tmusec == 0)
#if 0
    return (EXECUTION_FAILURE);
#else
    return (input_avail (fd) ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
#endif

  /* If we're asked to ignore the delimiter, make sure we do. */
  if (ignore_delim)
    delim = -1;

  /* IF IFS is unset, we use the default of " \t\n". */
  ifs_chars = getifs ();
  if (ifs_chars == 0)		/* XXX - shouldn't happen */
    ifs_chars = "";
  /* If we want to read exactly NCHARS chars, don't split on IFS */
  if (ignore_delim)
    ifs_chars = "";
  for (skip_ctlesc = skip_ctlnul = 0, e = ifs_chars; *e; e++)
    skip_ctlesc |= *e == CTLESC, skip_ctlnul |= *e == CTLNUL;

  input_string = (char *)xmalloc (size = 112);	/* XXX was 128 */
  input_string[0] = '\0';

  /* $TMOUT, if set, is the default timeout for read. */
  if (have_timeout == 0 && (e = get_string_value ("TMOUT")))
    {
      code = uconvert (e, &ival, &uval);
      if (code == 0 || ival < 0 || uval < 0)
	tmsec = tmusec = 0;
      else
	{
	  tmsec = ival;
	  tmusec = uval;
	}
    }

  begin_unwind_frame ("read_builtin");

#if defined (BUFFERED_INPUT)
  if (interactive == 0 && default_buffered_input >= 0 && fd_is_bash_input (fd))
    sync_buffered_stream (default_buffered_input);
#endif

  input_is_tty = isatty (fd);
  if (input_is_tty == 0)
#ifndef __CYGWIN__
    input_is_pipe = (lseek (fd, 0L, SEEK_CUR) < 0) && (errno == ESPIPE);
#else
    input_is_pipe = 1;
#endif

  /* If the -p, -e or -s flags were given, but input is not coming from the
     terminal, turn them off. */
  if ((prompt || edit || silent) && input_is_tty == 0)
    {
      prompt = (char *)NULL;
#if defined (READLINE)
      itext = (char *)NULL;
#endif
      edit = silent = 0;
    }

#if defined (READLINE)
  if (edit)
    add_unwind_protect (xfree, rlbuf);
#endif

  pass_next = 0;	/* Non-zero signifies last char was backslash. */
  saw_escape = 0;	/* Non-zero signifies that we saw an escape char */

  if (tmsec > 0 || tmusec > 0)
    {
      /* Turn off the timeout if stdin is a regular file (e.g. from
	 input redirection). */
      if ((fstat (fd, &tsb) < 0) || S_ISREG (tsb.st_mode))
	tmsec = tmusec = 0;
    }

  if (tmsec > 0 || tmusec > 0)
    {
      code = setjmp (alrmbuf);
      if (code)
	{
	  /* Tricky.  The top of the unwind-protect stack is the free of
	     input_string.  We want to run all the rest and use input_string,
	     so we have to remove it from the stack. */
	  remove_unwind_protect ();
	  run_unwind_frame ("read_builtin");
	  input_string[i] = '\0';	/* make sure it's terminated */
	  retval = 128+SIGALRM;
	  goto assign_vars;
	}
      old_alrm = set_signal_handler (SIGALRM, sigalrm);
      add_unwind_protect (reset_alarm, (char *)NULL);
#if defined (READLINE)
      if (edit)
	add_unwind_protect (reset_attempted_completion_function, (char *)NULL);
#endif
      falarm (tmsec, tmusec);
    }

  /* If we've been asked to read only NCHARS chars, or we're using some
     character other than newline to terminate the line, do the right
     thing to readline or the tty. */
  if (nchars > 0 || delim != '\n')
    {
#if defined (READLINE)
      if (edit)
	{
	  if (nchars > 0)
	    {
	      unwind_protect_int (rl_num_chars_to_read);
	      rl_num_chars_to_read = nchars;
	    }
	  if (delim != '\n')
	    {
	      set_eol_delim (delim);
	      add_unwind_protect (reset_eol_delim, (char *)NULL);
	    }
	}
      else
#endif
      if (input_is_tty)
	{
	  /* ttsave() */
	  termsave.fd = fd;
	  ttgetattr (fd, &ttattrs);
	  termsave.attrs = &ttattrs;

	  ttset = ttattrs;	  
	  i = silent ? ttfd_cbreak (fd, &ttset) : ttfd_onechar (fd, &ttset);
	  if (i < 0)
	    sh_ttyerror (1);
	  add_unwind_protect ((Function *)ttyrestore, (char *)&termsave);
	}
    }
  else if (silent)	/* turn off echo but leave term in canonical mode */
    {
      /* ttsave (); */
      termsave.fd = fd;
      ttgetattr (fd, &ttattrs);
      termsave.attrs = &ttattrs;

      ttset = ttattrs;
      i = ttfd_noecho (fd, &ttset);			/* ttnoecho (); */
      if (i < 0)
	sh_ttyerror (1);

      add_unwind_protect ((Function *)ttyrestore, (char *)&termsave);
    }

  /* This *must* be the top unwind-protect on the stack, so the manipulation
     of the unwind-protect stack after the realloc() works right. */
  add_unwind_protect (xfree, input_string);
  interrupt_immediately++;
  terminate_immediately++;

  unbuffered_read = (nchars > 0) || (delim != '\n') || input_is_pipe;

  if (prompt && edit == 0)
    {
      fprintf (stderr, "%s", prompt);
      fflush (stderr);
    }

#if defined (__CYGWIN__) && defined (O_TEXT)
  setmode (0, O_TEXT);
#endif

  ps2 = 0;
  for (print_ps2 = eof = retval = 0;;)
    {
#if defined (READLINE)
      if (edit)
	{
	  if (rlbuf && rlbuf[rlind] == '\0')
	    {
	      xfree (rlbuf);
	      rlbuf = (char *)0;
	    }
	  if (rlbuf == 0)
	    {
	      rlbuf = edit_line (prompt ? prompt : "", itext);
	      rlind = 0;
	    }
	  if (rlbuf == 0)
	    {
	      eof = 1;
	      break;
	    }
	  c = rlbuf[rlind++];
	}
      else
	{
#endif