iwordexp.c

Intercom 是一个 Unix系统上灵活的语音传输软件。支持标准音频压缩比如GSM, G.711, and G.72x和其他音频编码。Intercom专为高速网络设计来传输高品质的语音

/* POSIX.2 wordexp implementation.
   Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Tim Waugh <[e-mail]>.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

/* Modified for Intercom by Shane Wegner <[e-mail]> */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <fnmatch.h>
#include <glob.h>
#include <paths.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#ifdef USE_IN_LIBIO
# include <wchar.h>
#endif
#ifdef USE_GETTEXT
#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif
#include <libintl.h>
#define _(String) gettext(String)
#define gettext_noop(String) (String)
#define N_(String) gettext_noop(String)
#else
#define _(String) (String)
#define N_(String) (String)
#endif

#include "iwordexp.h"

/* Undefine the following line for the production version.  */
/* #define NDEBUG 1 */
#include <assert.h>

#ifndef internal_function
#define internal_function
#endif
extern char **environ;

#ifndef strdupa
/* Duplicate S, returning an identical alloca'd string.  */
# define strdupa(s)                                                           \
    (({                                                                        \
      __const char *__old = (s);                                              \
      size_t __len = strlen (__old) + 1;                                      \
      char *__new = (char *) alloca (__len);                        \
      (char *) memcpy (__new, __old, __len);                                  \
    }))
#endif
#ifndef strndupa
/* Return an alloca'd copy of at most N bytes of string.  */
# define strndupa(s, n)                                                       \
    (({                                                                        \
      __const char *__old = (s);                                              \
      size_t __len = strnlen (__old, (n));                                    \
      char *__new = (char *) alloca (__len + 1);                    \
      __new[__len] = '\0';                                                    \
      (char *) memcpy (__new, __old, __len);                                  \
    }))
#endif


/*
 * This is a recursive-descent-style word expansion routine.
 */

/* Some forward declarations */
static int parse_dollars (char **word, size_t *word_length, size_t *max_length,
			  const char *words, size_t *offset, int flags,
			  wordexp_t *pwordexp, const char *ifs,
			  const char *ifs_white, int quoted)
     internal_function;
static int parse_backtick (char **word, size_t *word_length,
			   size_t *max_length, const char *words,
			   size_t *offset, int flags, wordexp_t *pwordexp,
			   const char *ifs, const char *ifs_white)
     internal_function;
static int parse_dquote (char **word, size_t *word_length, size_t *max_length,
			 const char *words, size_t *offset, int flags,
			 wordexp_t *pwordexp, const char *ifs,
			 const char *ifs_white)
     internal_function;
static int eval_expr (char *expr, long int *result) internal_function;
/* Convert VALUE into ASCII in base BASE (2..36).
   Write backwards starting the character just before BUFLIM.
   Return the address of the first (left-to-right) character in the number.
   Use upper case letters iff UPPER_CASE is nonzero.  */
static char *itoa (unsigned long long int value, char *buflim,
		    unsigned int base, int upper_case);
#define itoa_word itoa

/* The w_*() functions manipulate word lists. */

#define W_CHUNK	(100)

/* Result of w_newword will be ignored if it's the last word. */
static inline char *
w_newword (size_t *actlen, size_t *maxlen)
{
  *actlen = *maxlen = 0;
  return NULL;
}

static inline char *
w_addchar (char *buffer, size_t *actlen, size_t *maxlen, char ch)
     /* (lengths exclude trailing zero) */
{
  /* Add a character to the buffer, allocating room for it if needed.
   */

  if (*actlen == *maxlen)
    {
      char *old_buffer = buffer;
      assert (buffer == NULL || *maxlen != 0);
      *maxlen += W_CHUNK;
      buffer = realloc (buffer, 1 + *maxlen);

      if (buffer == NULL)
	free (old_buffer);
    }

  if (buffer != NULL)
    {
      buffer[*actlen] = ch;
      buffer[++(*actlen)] = '\0';
    }

  return buffer;
}

static char *
internal_function
w_addmem (char *buffer, size_t *actlen, size_t *maxlen, const char *str,
	  size_t len)
{
  /* Add a string to the buffer, allocating room for it if needed.
   */
  if (*actlen + len > *maxlen)
    {
      char *old_buffer = buffer;
      assert (buffer == NULL || *maxlen != 0);
      *maxlen += MAX (2 * len, W_CHUNK);
      buffer = realloc (old_buffer, 1 + *maxlen);

      if (buffer == NULL)
	free (old_buffer);
    }

  if (buffer != NULL)
    {
      *((char *) mempcpy (&buffer[*actlen], str, len)) = '\0';
      *actlen += len;
    }

  return buffer;
}

static char *
internal_function
w_addstr (char *buffer, size_t *actlen, size_t *maxlen, const char *str)
     /* (lengths exclude trailing zero) */
{
  /* Add a string to the buffer, allocating room for it if needed.
   */
  size_t len;

  assert (str != NULL); /* w_addstr only called from this file */
  len = strlen (str);

  return w_addmem (buffer, actlen, maxlen, str, len);
}

static int
internal_function
w_addword (wordexp_t *pwordexp, char *word)
{
  /* Add a word to the wordlist */
  size_t num_p;
  char **new_wordv;

  /* Internally, NULL acts like "".  Convert NULLs to "" before
   * the caller sees them.
   */
  if (word == NULL)
    {
      word = strdup ("");
      if (word == NULL)
	goto no_space;
    }

  num_p = 2 + pwordexp->we_wordc + pwordexp->we_offs;
  new_wordv = realloc (pwordexp->we_wordv, sizeof (char *) * num_p);
  if (new_wordv != NULL)
    {
      pwordexp->we_wordv = new_wordv;
      pwordexp->we_wordv[pwordexp->we_offs + pwordexp->we_wordc++] = word;
      pwordexp->we_wordv[pwordexp->we_offs + pwordexp->we_wordc] = NULL;
      return 0;
    }

no_space:
  return WRDE_NOSPACE;
}

/* The parse_*() functions should leave *offset being the offset in 'words'
 * to the last character processed.
 */

static int
internal_function
parse_backslash (char **word, size_t *word_length, size_t *max_length,
		 const char *words, size_t *offset)
{
  /* We are poised _at_ a backslash, not in quotes */

  switch (words[1 + *offset])
    {
    case 0:
      /* Backslash is last character of input words */
      return WRDE_SYNTAX;

    case '\n':
      ++(*offset);
      break;

    default:
      *word = w_addchar (*word, word_length, max_length, words[1 + *offset]);
      if (*word == NULL)
	return WRDE_NOSPACE;

      ++(*offset);
      break;
    }

  return 0;
}

static int
internal_function
parse_qtd_backslash (char **word, size_t *word_length, size_t *max_length,
		     const char *words, size_t *offset)
{
  /* We are poised _at_ a backslash, inside quotes */

  switch (words[1 + *offset])
    {
    case 0:
      /* Backslash is last character of input words */
      return WRDE_SYNTAX;

    case '\n':
      ++(*offset);
      break;

    case '$':
    case '`':
    case '"':
    case '\\':
      *word = w_addchar (*word, word_length, max_length, words[1 + *offset]);
      if (*word == NULL)
	return WRDE_NOSPACE;

      ++(*offset);
      break;

    default:
      *word = w_addchar (*word, word_length, max_length, words[*offset]);
      if (*word != NULL)
	*word = w_addchar (*word, word_length, max_length, words[1 + *offset]);

      if (*word == NULL)
	return WRDE_NOSPACE;

      ++(*offset);
      break;
    }

  return 0;
}

static int
internal_function
parse_tilde (char **word, size_t *word_length, size_t *max_length,
	     const char *words, size_t *offset, size_t wordc)
{
  /* We are poised _at_ a tilde */
  size_t i;

  if (*word_length != 0)
    {
      if (!((*word)[*word_length - 1] == '=' && wordc == 0))
	{
	  if (!((*word)[*word_length - 1] == ':'
		&& strchr (*word, '=') && wordc == 0))
	    {
	      *word = w_addchar (*word, word_length, max_length, '~');
	      return *word ? 0 : WRDE_NOSPACE;
	    }
	}
    }

  for (i = 1 + *offset; words[i]; i++)
    {
      if (words[i] == ':' || words[i] == '/' || words[i] == ' ' ||
	  words[i] == '\t' || words[i] == 0 )
	break;

      if (words[i] == '\\')
	{
	  *word = w_addchar (*word, word_length, max_length, '~');
	  return *word ? 0 : WRDE_NOSPACE;
	}
    }

  if (i == 1 + *offset)
    {
      /* Tilde appears on its own */
      uid_t uid;
      struct passwd *pwd;
      char* home;

      /* POSIX.2 says ~ expands to $HOME and if HOME is unset the
	 results are unspecified.  We do a lookup on the uid if
	 HOME is unset. */

      home = getenv ("HOME");
      if (home != NULL)
	{
	  *word = w_addstr (*word, word_length, max_length, home);
	  if (*word == NULL)
	    return WRDE_NOSPACE;
	}
      else
	{
	  uid = getuid ();

	  if ((pwd = getpwuid (uid)) != NULL)
	    {
	      *word = w_addstr (*word, word_length, max_length, pwd->pw_dir);
	      if (*word == NULL)
		return WRDE_NOSPACE;
	    }
	  else
	    {
	      *word = w_addchar (*word, word_length, max_length, '~');
	      if (*word == NULL)
		return WRDE_NOSPACE;
	    }
	}
    }
  else
    {
      /* Look up user name in database to get home directory */
      char *user = strndupa (&words[1 + *offset], i - (1 + *offset));
      struct passwd *pwd;

      if ((pwd = getpwnam (user)) != NULL)
	*word = w_addstr (*word, word_length, max_length, pwd->pw_dir);
      else
	{
	  /* (invalid login name) */
	  *word = w_addchar (*word, word_length, max_length, '~');
	  if (*word != NULL)
	    *word = w_addstr (*word, word_length, max_length, user);
	}

      *offset = i - 1;
    }
  return *word ? 0 : WRDE_NOSPACE;
}


static int
internal_function
do_parse_glob (const char *glob_word, char **word, size_t *word_length,
	       size_t *max_length, wordexp_t *pwordexp, const char *ifs,
	       const char *ifs_white)
{
  int error;
  unsigned int match;
  glob_t globbuf;

  error = glob (glob_word, GLOB_NOCHECK, NULL, &globbuf);

  if (error != 0)
    {
      /* We can only run into memory problems.  */
      assert (error == GLOB_NOSPACE);
      return WRDE_NOSPACE;
    }

  if (ifs && !*ifs)
    {
      /* No field splitting allowed. */
      assert (globbuf.gl_pathv[0] != NULL);
      *word = w_addstr (*word, word_length, max_length, globbuf.gl_pathv[0]);
      for (match = 1; match < globbuf.gl_pathc && *word != NULL; ++match)
	{
	  *word = w_addchar (*word, word_length, max_length, ' ');
	  if (*word != NULL)
	    *word = w_addstr (*word, word_length, max_length,
			      globbuf.gl_pathv[match]);
	}

      globfree (&globbuf);
      return *word ? 0 : WRDE_NOSPACE;
    }

  assert (ifs == NULL || *ifs != '\0');
  if (*word != NULL)
    {
      free (*word);
      *word = w_newword (word_length, max_length);
    }

  for (match = 0; match < globbuf.gl_pathc; ++match)
    {
      char *matching_word = strdup (globbuf.gl_pathv[match]);
      if (matching_word == NULL || w_addword (pwordexp, matching_word))
	{
	  globfree (&globbuf);
	  return WRDE_NOSPACE;
	}
    }

  globfree (&globbuf);
  return 0;
}

static int
internal_function
parse_glob (char **word, size_t *word_length, size_t *max_length,
	    const char *words, size_t *offset, int flags,
	    wordexp_t *pwordexp, const char *ifs, const char *ifs_white)
{
  /* We are poised just after a '*', a '[' or a '?'. */
  int error = WRDE_NOSPACE;
  int quoted = 0; /* 1 if singly-quoted, 2 if doubly */
  int i;
  wordexp_t glob_list; /* List of words to glob */

  glob_list.we_wordc = 0;
  glob_list.we_wordv = NULL;
  glob_list.we_offs = 0;
  for (; words[*offset] != '\0'; ++*offset)
    {
      if ((ifs && strchr (ifs, words[*offset])) ||
	  (!ifs && strchr (" \t\n", words[*offset])))
	/* Reached IFS */
	break;

      /* Sort out quoting */
      if (words[*offset] == '\'')
	{
	  if (quoted == 0)
	    {
	      quoted = 1;
	      continue;
	    }
	  else if (quoted == 1)
	    {
	      quoted = 0;
	      continue;
	    }
	}
      else if (words[*offset] == '"')
	{
	  if (quoted == 0)
	    {
	      quoted = 2;
	      continue;
	    }
	  else if (quoted == 2)
	    {
	      quoted = 0;
	      continue;
	    }
	}

      /* Sort out other special characters */
      if (quoted != 1 && words[*offset] == '$')
	{
	  error = parse_dollars (word, word_length, max_length, words,
				 offset, flags, &glob_list, ifs, ifs_white,
				 quoted == 2);
	  if (error)
	    goto tidy_up;

	  continue;
	}
      else if (words[*offset] == '\\')
	{
	  if (quoted)
	    error = parse_qtd_backslash (word, word_length, max_length,
					 words, offset);
	  else
	    error = parse_backslash (word, word_length, max_length,
				     words, offset);

	  if (error)
	    goto tidy_up;

	  continue;
	}

      *word = w_addchar (*word, word_length, max_length, words[*offset]);
      if (*word == NULL)
	goto tidy_up;
    }

  /* Don't forget to re-parse the character we stopped at. */
  --*offset;

  /* Glob the words */
  error = w_addword (&glob_list, *word);
  *word = w_newword (word_length, max_length);
  for (i = 0; error == 0 && i < glob_list.we_wordc; i++)
    error = do_parse_glob (glob_list.we_wordv[i], word, word_length,
			   max_length, pwordexp, ifs, ifs_white);

  /* Now tidy up */
tidy_up:
  iwordfree (&glob_list);
  return error;
}

static int
internal_function
parse_squote (char **word, size_t *word_length, size_t *max_length,
	      const char *words, size_t *offset)
{
  /* We are poised just after a single quote */
  for (; words[*offset]; ++(*offset))
    {
      if (words[*offset] != '\'')
	{
	  *word = w_addchar (*word, word_length, max_length, words[*offset]);
	  if (*word == NULL)
	    return WRDE_NOSPACE;
	}
      else return 0;
    }

  /* Unterminated string */
  return WRDE_SYNTAX;
}

/* Functions to evaluate an arithmetic expression */
static int
internal_function
eval_expr_val (char **expr, long int *result)
{
  int sgn = +1;
  char *digit;

  /* Skip white space */
  for (digit = *expr; digit && *digit && isspace (*digit); ++digit);

  switch (*digit)
    {
    case '(':

      /* Scan for closing paren */
      for (++digit; **expr && **expr != ')'; ++(*expr));

      /* Is there one? */
      if (!**expr)
	return WRDE_SYNTAX;