Updated to fedora-glibc-20051219T1003 cvs/fedora-glibc-2_3_90-19

1 files changed, 2457 insertions, 0 deletions

diff --git a/posix/wordexp.c b/posix/wordexp.c
new file mode 100644
index 0000000000..2eb58089c4
--- /dev/null
+++ b/posix/wordexp.c
@@ -0,0 +1,2457 @@
+/* POSIX.2 wordexp implementation.
+   Copyright (C) 1997-2002, 2003, 2005 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Tim Waugh <tim@cyberelk.demon.co.uk>.
+
+   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.  */
+
+#include <alloca.h>
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <fnmatch.h>
+#include <glob.h>
+#include <libintl.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
+#include <wordexp.h>
+
+#include <bits/libc-lock.h>
+#include <stdio-common/_itoa.h>
+
+/* Undefine the following line for the production version.  */
+/* #define NDEBUG 1 */
+#include <assert.h>
+
+/* Get some device information.  */
+#include <device-nrs.h>
+
+/*
+ * This is a recursive-descent-style word expansion routine.
+ */
+
+/* These variables are defined and initialized in the startup code.  */
+extern int __libc_argc attribute_hidden;
+extern char **__libc_argv attribute_hidden;
+
+/* 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;
+
+/* 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 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 = (char *) 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, *tpwd;
+      int buflen = 1000;
+      char* home;
+      char* buffer;
+      int result;
+
+      /* 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 ();
+	  buffer = __alloca (buflen);
+
+	  while ((result = __getpwuid_r (uid, &pwd, buffer, buflen, &tpwd)) != 0
+		 && errno == ERANGE)
+	    buffer = extend_alloca (buffer, buflen, buflen + 1000);
+
+	  if (result == 0 && tpwd != NULL && pwd.pw_dir != 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, *tpwd;
+      int buflen = 1000;
+      char* buffer = __alloca (buflen);
+      int result;
+
+      while ((result = __getpwnam_r (user, &pwd, buffer, buflen, &tpwd)) != 0
+	     && errno == ERANGE)
+	buffer = extend_alloca (buffer, buflen, buflen + 1000);
+
+      if (result == 0 && tpwd != NULL && pwd.pw_dir)
+	*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 */
+  size_t 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:
+  wordfree (&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)
+{
+  char *digit;
+
+  /* Skip white space */
+  for (digit = *expr; digit && *digit && isspace (*digit); ++digit);
+
+  if (*digit == '(')
+    {
+      /* Scan for closing paren */
+      for (++digit; **expr && **expr != ')'; ++(*expr));
+
+      /* Is there one? */
+      if (!**expr)
+	return WRDE_SYNTAX;
+
+      *(*expr)++ = 0;
+
+      if (eval_expr (digit, result))
+	return WRDE_SYNTAX;
+
+      return 0;
+    }
+
+  /* POSIX requires that decimal, octal, and hexadecimal constants are
+     recognized.  Therefore we pass 0 as the third parameter to strtol.  */
+  *result = strtol (digit, expr, 0);
+  if (digit == *expr)
+    return WRDE_SYNTAX;
+
+  return 0;
+}
+
+static int
+internal_function
+eval_expr_multdiv (char **expr, long int *result)
+{
+  long int arg;
+
+  /* Read a Value */
+  if (eval_expr_val (expr, result) != 0)
+    return WRDE_SYNTAX;
+
+  while (**expr)
+    {
+      /* Skip white space */
+      for (; *expr && **expr && isspace (**expr); ++(*expr));
+
+      if (**expr == '*')
+	{
+	  ++(*expr);
+	  if (eval_expr_val (expr, &arg) != 0)
+	    return WRDE_SYNTAX;
+
+	  *result *= arg;
+	}
+      else if (**expr == '/')
+	{
+	  ++(*expr);
+	  if (eval_expr_val (expr, &arg) != 0)
+	    return WRDE_SYNTAX;
+
+	  *result /= arg;
+	}
+      else break;
+    }
+
+  return 0;
+}
+
+static int
+internal_function
+eval_expr (char *expr, long int *result)
+{
+  long int arg;
+
+  /* Read a Multdiv */
+  if (eval_expr_multdiv (&expr, result) != 0)
+    return WRDE_SYNTAX;
+
+  while (*expr)
+    {
+      /* Skip white space */
+      for (; expr && *expr && isspace (*expr); ++expr);
+
+      if (*expr == '+')
+	{
+	  ++expr;
+	  if (eval_expr_multdiv (&expr, &arg) != 0)
+	    return WRDE_SYNTAX;
+
+	  *result += arg;
+	}
+      else if (*expr == '-')
+	{
+	  ++expr;
+	  if (eval_expr_multdiv (&expr, &arg) != 0)
+	    return WRDE_SYNTAX;
+
+	  *result -= arg;
+	}
+      else break;
+    }
+
+  return 0;
+}
+
+static int
+internal_function
+parse_arith (char **word, size_t *word_length, size_t *max_length,
+	     const char *words, size_t *offset, int flags, int bracket)
+{
+  /* We are poised just after "$((" or "$[" */
+  int error;
+  int paren_depth = 1;
+  size_t expr_length;
+  size_t expr_maxlen;
+  char *expr;
+
+  expr = w_newword (&expr_length, &expr_maxlen);
+  for (; words[*offset]; ++(*offset))
+    {
+      switch (words[*offset])
+	{
+	case '$':
+	  error = parse_dollars (&expr, &expr_length, &expr_maxlen,
+				 words, offset, flags, NULL, NULL, NULL, 1);
+	  /* The ``1'' here is to tell parse_dollars not to
+	   * split the fields.
+	   */
+	  if (error)
+	    {
+	      free (expr);
+	      return error;
+	    }
+	  break;
+
+	case '`':
+	  (*offset)++;
+	  error = parse_backtick (&expr, &expr_length, &expr_maxlen,
+				  words, offset, flags, NULL, NULL, NULL);
+	  /* The first NULL here is to tell parse_backtick not to
+	   * split the fields.
+	   */
+	  if (error)
+	    {
+	      free (expr);
+	      return error;
+	    }
+	  break;
+
+	case '\\':
+	  error = parse_qtd_backslash (&expr, &expr_length, &expr_maxlen,
+				       words, offset);
+	  if (error)
+	    {
+	      free (expr);
+	      return error;
+	    }
+	  /* I think that a backslash within an
+	   * arithmetic expansion is bound to
+	   * cause an error sooner or later anyway though.
+	   */
+	  break;
+
+	case ')':
+	  if (--paren_depth == 0)
+	    {
+	      char result[21];	/* 21 = ceil(log10(2^64)) + 1 */
+	      long int numresult = 0;
+	      long long int convertme;
+
+	      if (bracket || words[1 + *offset] != ')')
+		{
+		  free (expr);
+		  return WRDE_SYNTAX;
+		}
+
+	      ++(*offset);
+
+	      /* Go - evaluate. */
+	      if (*expr && eval_expr (expr, &numresult) != 0)
+		{
+		  free (expr);
+		  return WRDE_SYNTAX;
+		}
+
+	      if (numresult < 0)
+		{
+		  convertme = -numresult;
+		  *word = w_addchar (*word, word_length, max_length, '-');
+		  if (!*word)
+		    {
+		      free (expr);
+		      return WRDE_NOSPACE;
+		    }
+		}
+	      else
+		convertme = numresult;
+
+	      result[20] = '\0';
+	      *word = w_addstr (*word, word_length, max_length,
+				_itoa (convertme, &result[20], 10, 0));
+	      free (expr);
+	      return *word ? 0 : WRDE_NOSPACE;
+	    }
+	  expr = w_addchar (expr, &expr_length, &expr_maxlen, words[*offset]);
+	  if (expr == NULL)
+	    return WRDE_NOSPACE;
+
+	  break;
+
+	case ']':
+	  if (bracket && paren_depth == 1)
+	    {
+	      char result[21];	/* 21 = ceil(log10(2^64)) + 1 */
+	      long int numresult = 0;
+
+	      /* Go - evaluate. */
+	      if (*expr && eval_expr (expr, &numresult) != 0)
+		{
+		  free (expr);
+		  return WRDE_SYNTAX;
+		}
+
+	      result[20] = '\0';
+	      *word = w_addstr (*word, word_length, max_length,
+				_itoa_word (numresult, &result[20], 10, 0));
+	      free (expr);
+	      return *word ? 0 : WRDE_NOSPACE;
+	    }
+
+	  free (expr);
+	  return WRDE_SYNTAX;
+
+	case '\n':
+	case ';':
+	case '{':
+	case '}':
+	  free (expr);
+	  return WRDE_BADCHAR;
+
+	case '(':
+	  ++paren_depth;
+	default:
+	  expr = w_addchar (expr, &expr_length, &expr_maxlen, words[*offset]);
+	  if (expr == NULL)
+	    return WRDE_NOSPACE;
+	}
+    }
+
+  /* Premature end */
+  free (expr);
+  return WRDE_SYNTAX;
+}
+
+/* Function called by child process in exec_comm() */
+static inline void
+internal_function __attribute__ ((always_inline))
+exec_comm_child (char *comm, int *fildes, int showerr, int noexec)
+{
+  const char *args[4] = { _PATH_BSHELL, "-c", comm, NULL };
+
+  /* Execute the command, or just check syntax? */
+  if (noexec)
+    args[1] = "-nc";
+
+  /* Redirect output.  */
+  __dup2 (fildes[1], STDOUT_FILENO);
+  __close (fildes[1]);
+
+  /* Redirect stderr to /dev/null if we have to.  */
+  if (showerr == 0)
+    {
+      struct stat64 st;
+      int fd;
+      __close (2);
+      fd = __open (_PATH_DEVNULL, O_WRONLY);
+      if (fd >= 0 && fd != 2)
+	{
+	  __dup2 (fd, STDERR_FILENO);
+	  __close (fd);
+	}
+      /* Be paranoid.  Check that we actually opened the /dev/null
+         device.  */
+      if (__builtin_expect (__fxstat64 (_STAT_VER, STDERR_FILENO, &st), 0) != 0
+	  || __builtin_expect (S_ISCHR (st.st_mode), 1) == 0
+#if defined DEV_NULL_MAJOR && defined DEV_NULL_MINOR
+	  || st.st_rdev != makedev (DEV_NULL_MAJOR, DEV_NULL_MINOR)
+#endif
+	  )
+	/* It's not the /dev/null device.  Stop right here.  The
+           problem is: how do we stop?  We use _exit() with an
+           hopefully unusual exit code.  */
+	_exit (90);
+    }
+
+  /* Make sure the subshell doesn't field-split on our behalf. */
+  __unsetenv ("IFS");
+
+  __close (fildes[0]);
+  __execve (_PATH_BSHELL, (char *const *) args, __environ);
+
+  /* Bad.  What now?  */
+  abort ();
+}
+
+/* Function to execute a command and retrieve the results */
+/* pwordexp contains NULL if field-splitting is forbidden */
+static int
+internal_function
+exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length,
+	   int flags, wordexp_t *pwordexp, const char *ifs,
+	   const char *ifs_white)
+{
+  int fildes[2];
+#define bufsize 128
+  int buflen;
+  int i;
+  int status = 0;
+  size_t maxnewlines = 0;
+  char buffer[bufsize];
+  pid_t pid;
+  int noexec = 0;
+
+  /* Don't fork() unless necessary */
+  if (!comm || !*comm)
+    return 0;
+
+  if (__pipe (fildes))
+    /* Bad */
+    return WRDE_NOSPACE;
+
+ again:
+  if ((pid = __fork ()) < 0)
+    {
+      /* Bad */
+      if (fildes[0] != -1)
+	__close (fildes[0]);
+      if (fildes[1] != -1)
+	__close (fildes[1]);
+      return WRDE_NOSPACE;
+    }
+
+  if (pid == 0)
+    exec_comm_child (comm, fildes, noexec ? 0 : flags & WRDE_SHOWERR, noexec);
+
+  /* Parent */
+
+  /* If we are just testing the syntax, only wait.  */
+  if (noexec)
+    return (TEMP_FAILURE_RETRY (__waitpid (pid, &status, 0)) == pid
+	    && status != 0) ? WRDE_SYNTAX : 0;
+
+  __close (fildes[1]);
+  fildes[1] = -1;
+
+  if (!pwordexp)
+    /* Quoted - no field splitting */
+    {
+      while (1)
+	{
+	  if ((buflen = TEMP_FAILURE_RETRY (__read (fildes[0], buffer,
+						    bufsize))) < 1)
+	    {
+	      if (TEMP_FAILURE_RETRY (__waitpid (pid, &status, WNOHANG)) == 0)
+		continue;
+	      if ((buflen = TEMP_FAILURE_RETRY (__read (fildes[0], buffer,
+							bufsize))) < 1)
+		break;
+	    }
+
+	  maxnewlines += buflen;
+
+	  *word = w_addmem (*word, word_length, max_length, buffer, buflen);
+	  if (*word == NULL)
+	    goto no_space;
+	}
+    }
+  else
+    /* Not quoted - split fields */
+    {
+      int copying = 0;
+      /* 'copying' is:
+       *  0 when searching for first character in a field not IFS white space
+       *  1 when copying the text of a field
+       *  2 when searching for possible non-whitespace IFS
+       *  3 when searching for non-newline after copying field
+       */
+
+      while (1)
+	{
+	  if ((buflen = TEMP_FAILURE_RETRY (__read (fildes[0], buffer,
+						    bufsize))) < 1)
+	    {
+	      if (TEMP_FAILURE_RETRY (__waitpid (pid, &status, WNOHANG)) == 0)
+		continue;
+	      if ((buflen = TEMP_FAILURE_RETRY (__read (fildes[0], buffer,
+							bufsize))) < 1)
+		break;
+	    }
+
+	  for (i = 0; i < buflen; ++i)
+	    {
+	      if (strchr (ifs, buffer[i]) != NULL)
+		{
+		  /* Current character is IFS */
+		  if (strchr (ifs_white, buffer[i]) == NULL)
+		    {
+		      /* Current character is IFS but not whitespace */
+		      if (copying == 2)
+			{
+			  /*            current character
+			   *                   |
+			   *                   V
+			   * eg: text<space><comma><space>moretext
+			   *
+			   * So, strip whitespace IFS (like at the start)
+			   */
+			  copying = 0;
+			  continue;
+			}
+
+		      copying = 0;
+		      /* fall through and delimit field.. */
+		    }
+		  else
+		    {
+		      if (buffer[i] == '\n')
+			{
+			  /* Current character is (IFS) newline */
+
+			  /* If copying a field, this is the end of it,
+			     but maybe all that's left is trailing newlines.
+			     So start searching for a non-newline. */
+			  if (copying == 1)
+			    copying = 3;
+
+			  continue;
+			}
+		      else
+			{
+			  /* Current character is IFS white space, but
+			     not a newline */
+
+			  /* If not either copying a field or searching
+			     for non-newline after a field, ignore it */
+			  if (copying != 1 && copying != 3)
+			    continue;
+
+			  /* End of field (search for non-ws IFS afterwards) */
+			  copying = 2;
+			}
+		    }
+
+		  /* First IFS white space (non-newline), or IFS non-whitespace.
+		   * Delimit the field.  Nulls are converted by w_addword. */
+		  if (w_addword (pwordexp, *word) == WRDE_NOSPACE)
+		    goto no_space;
+
+		  *word = w_newword (word_length, max_length);
+
+		  maxnewlines = 0;
+		  /* fall back round the loop.. */
+		}
+	      else
+		{
+		  /* Not IFS character */
+
+		  if (copying == 3)
+		    {
+		      /* Nothing but (IFS) newlines since the last field,
+		         so delimit it here before starting new word */
+		      if (w_addword (pwordexp, *word) == WRDE_NOSPACE)
+			goto no_space;
+
+		      *word = w_newword (word_length, max_length);
+		    }
+
+		  copying = 1;
+
+		  if (buffer[i] == '\n') /* happens if newline not in IFS */
+		    maxnewlines++;
+		  else
+		    maxnewlines = 0;
+
+		  *word = w_addchar (*word, word_length, max_length,
+				     buffer[i]);
+		  if (*word == NULL)
+		    goto no_space;
+		}
+	    }
+	}
+    }
+
+  /* Chop off trailing newlines (required by POSIX.2)  */
+  /* Ensure we don't go back further than the beginning of the
+     substitution (i.e. remove maxnewlines bytes at most) */
+  while (maxnewlines-- != 0 &&
+         *word_length > 0 && (*word)[*word_length - 1] == '\n')
+    {
+      (*word)[--*word_length] = '\0';
+
+      /* If the last word was entirely newlines, turn it into a new word
+       * which can be ignored if there's nothing following it. */
+      if (*word_length == 0)
+	{
+	  free (*word);
+	  *word = w_newword (word_length, max_length);
+	  break;
+	}
+    }
+
+  __close (fildes[0]);
+  fildes[0] = -1;
+
+  /* Check for syntax error (re-execute but with "-n" flag) */
+  if (buflen < 1 && status != 0)
+    {
+      noexec = 1;
+      goto again;
+    }
+
+  return 0;
+
+no_space:
+  __kill (pid, SIGKILL);
+  TEMP_FAILURE_RETRY (__waitpid (pid, NULL, 0));
+  __close (fildes[0]);
+  return WRDE_NOSPACE;
+}
+
+static int
+internal_function
+parse_comm (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 "$(" */
+  int paren_depth = 1;
+  int error = 0;
+  int quoted = 0; /* 1 for singly-quoted, 2 for doubly-quoted */
+  size_t comm_length;
+  size_t comm_maxlen;
+  char *comm = w_newword (&comm_length, &comm_maxlen);
+
+  for (; words[*offset]; ++(*offset))
+    {
+      switch (words[*offset])
+	{
+	case '\'':
+	  if (quoted == 0)
+	    quoted = 1;
+	  else if (quoted == 1)
+	    quoted = 0;
+
+	  break;
+
+	case '"':
+	  if (quoted == 0)
+	    quoted = 2;
+	  else if (quoted == 2)
+	    quoted = 0;
+
+	  break;
+
+	case ')':
+	  if (!quoted && --paren_depth == 0)
+	    {
+	      /* Go -- give script to the shell */
+	      if (comm)
+		{
+#ifdef __libc_ptf_call
+		  /* We do not want the exec_comm call to be cut short
+		     by a thread cancellation since cleanup is very
+		     ugly.  Therefore disable cancellation for
+		     now.  */
+		  // XXX Ideally we do want the thread being cancelable.
+		  // XXX If demand is there we'll change it.
+		  int state = PTHREAD_CANCEL_ENABLE;
+		  __libc_ptf_call (pthread_setcancelstate,
+				   (PTHREAD_CANCEL_DISABLE, &state), 0);
+#endif
+
+		  error = exec_comm (comm, word, word_length, max_length,
+				     flags, pwordexp, ifs, ifs_white);
+
+#ifdef __libc_ptf_call
+		  __libc_ptf_call (pthread_setcancelstate, (state, NULL), 0);
+#endif
+
+		  free (comm);
+		}
+
+	      return error;
+	    }
+
+	  /* This is just part of the script */
+	  break;
+
+	case '(':
+	  if (!quoted)
+	    ++paren_depth;
+	}
+
+      comm = w_addchar (comm, &comm_length, &comm_maxlen, words[*offset]);
+      if (comm == NULL)
+	return WRDE_NOSPACE;
+    }
+
+  /* Premature end */
+  if (comm)
+    free (comm);
+
+  return WRDE_SYNTAX;
+}
+
+static int
+internal_function
+parse_param (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)
+{
+  /* We are poised just after "$" */
+  enum action
+  {
+    ACT_NONE,
+    ACT_RP_SHORT_LEFT = '#',
+    ACT_RP_LONG_LEFT = 'L',
+    ACT_RP_SHORT_RIGHT = '%',
+    ACT_RP_LONG_RIGHT = 'R',
+    ACT_NULL_ERROR = '?',
+    ACT_NULL_SUBST = '-',
+    ACT_NONNULL_SUBST = '+',
+    ACT_NULL_ASSIGN = '='
+  };
+  size_t env_length;
+  size_t env_maxlen;
+  size_t pat_length;
+  size_t pat_maxlen;
+  size_t start = *offset;
+  char *env;
+  char *pattern;
+  char *value = NULL;
+  enum action action = ACT_NONE;
+  int depth = 0;
+  int colon_seen = 0;
+  int seen_hash = 0;
+  int free_value = 0;
+  int pattern_is_quoted = 0; /* 1 for singly-quoted, 2 for doubly-quoted */
+  int error;
+  int special = 0;
+  char buffer[21];
+  int brace = words[*offset] == '{';
+
+  env = w_newword (&env_length, &env_maxlen);
+  pattern = w_newword (&pat_length, &pat_maxlen);
+
+  if (brace)
+    ++*offset;
+
+  /* First collect the parameter name. */
+
+  if (words[*offset] == '#')
+    {
+      seen_hash = 1;
+      if (!brace)
+	goto envsubst;
+      ++*offset;
+    }
+
+  if (isalpha (words[*offset]) || words[*offset] == '_')
+    {
+      /* Normal parameter name. */
+      do
+	{
+	  env = w_addchar (env, &env_length, &env_maxlen,
+			   words[*offset]);
+	  if (env == NULL)
+	    goto no_space;
+	}
+      while (isalnum (words[++*offset]) || words[*offset] == '_');
+    }
+  else if (isdigit (words[*offset]))
+    {
+      /* Numeric parameter name. */
+      special = 1;
+      do
+	{
+	  env = w_addchar (env, &env_length, &env_maxlen,
+			   words[*offset]);
+	  if (env == NULL)
+	    goto no_space;
+	  if (!brace)
+	    goto envsubst;
+	}
+      while (isdigit(words[++*offset]));
+    }
+  else if (strchr ("*@$", words[*offset]) != NULL)
+    {
+      /* Special parameter. */
+      special = 1;
+      env = w_addchar (env, &env_length, &env_maxlen,
+		       words[*offset]);
+      if (env == NULL)
+	goto no_space;
+      ++*offset;
+    }
+  else
+    {
+      if (brace)
+	goto syntax;
+    }
+
+  if (brace)
+    {
+      /* Check for special action to be applied to the value. */
+      switch (words[*offset])
+	{
+	case '}':
+	  /* Evaluate. */
+	  goto envsubst;
+
+	case '#':
+	  action = ACT_RP_SHORT_LEFT;
+	  if (words[1 + *offset] == '#')
+	    {
+	      ++*offset;
+	      action = ACT_RP_LONG_LEFT;
+	    }
+	  break;
+
+	case '%':
+	  action = ACT_RP_SHORT_RIGHT;
+	  if (words[1 + *offset] == '%')
+	    {
+	      ++*offset;
+	      action = ACT_RP_LONG_RIGHT;
+	    }
+	  break;
+
+	case ':':
+	  if (strchr ("-=?+", words[1 + *offset]) == NULL)
+	    goto syntax;
+
+	  colon_seen = 1;
+	  action = words[++*offset];
+	  break;
+
+	case '-':
+	case '=':
+	case '?':
+	case '+':
+	  action = words[*offset];
+	  break;
+
+	default:
+	  goto syntax;
+	}
+
+      /* Now collect the pattern, but don't expand it yet. */
+      ++*offset;
+      for (; words[*offset]; ++(*offset))
+	{
+	  switch (words[*offset])
+	    {
+	    case '{':
+	      if (!pattern_is_quoted)
+		++depth;
+	      break;
+
+	    case '}':
+	      if (!pattern_is_quoted)
+		{
+		  if (depth == 0)
+		    goto envsubst;
+		  --depth;
+		}
+	      break;
+
+	    case '\\':
+	      if (pattern_is_quoted)
+		/* Quoted; treat as normal character. */
+		break;
+
+	      /* Otherwise, it's an escape: next character is literal. */
+	      if (words[++*offset] == '\0')
+		goto syntax;
+
+	      pattern = w_addchar (pattern, &pat_length, &pat_maxlen, '\\');
+	      if (pattern == NULL)
+		goto no_space;
+
+	      break;
+
+	    case '\'':
+	      if (pattern_is_quoted == 0)
+		pattern_is_quoted = 1;
+	      else if (pattern_is_quoted == 1)
+		pattern_is_quoted = 0;
+
+	      break;
+
+	    case '"':
+	      if (pattern_is_quoted == 0)
+		pattern_is_quoted = 2;
+	      else if (pattern_is_quoted == 2)
+		pattern_is_quoted = 0;
+
+	      break;
+	    }
+
+	  pattern = w_addchar (pattern, &pat_length, &pat_maxlen,
+			       words[*offset]);
+	  if (pattern == NULL)
+	    goto no_space;
+	}
+    }
+
+  /* End of input string -- remember to reparse the character that we
+   * stopped at.  */
+  --(*offset);
+
+envsubst:
+  if (words[start] == '{' && words[*offset] != '}')
+    goto syntax;
+
+  if (env == NULL)
+    {
+      if (seen_hash)
+	{
+	  /* $# expands to the number of positional parameters */
+	  buffer[20] = '\0';
+	  value = _itoa_word (__libc_argc - 1, &buffer[20], 10, 0);
+	  seen_hash = 0;
+	}
+      else
+	{
+	  /* Just $ on its own */
+	  *offset = start - 1;
+	  *word = w_addchar (*word, word_length, max_length, '$');
+	  return *word ? 0 : WRDE_NOSPACE;
+	}
+    }
+  /* Is it a numeric parameter? */
+  else if (isdigit (env[0]))
+    {
+      int n = atoi (env);
+
+      if (n >= __libc_argc)
+	/* Substitute NULL. */
+	value = NULL;
+      else
+	/* Replace with appropriate positional parameter. */
+	value = __libc_argv[n];
+    }
+  /* Is it a special parameter? */
+  else if (special)
+    {
+      /* Is it `$$'? */
+      if (*env == '$')
+	{
+	  buffer[20] = '\0';
+	  value = _itoa_word (__getpid (), &buffer[20], 10, 0);
+	}
+      /* Is it `${#*}' or `${#@}'? */
+      else if ((*env == '*' || *env == '@') && seen_hash)
+	{
+	  buffer[20] = '\0';
+	  value = _itoa_word (__libc_argc > 0 ? __libc_argc - 1 : 0,
+			      &buffer[20], 10, 0);
+	  *word = w_addstr (*word, word_length, max_length, value);
+	  free (env);
+	  if (pattern)
+	    free (pattern);
+	  return *word ? 0 : WRDE_NOSPACE;
+	}
+      /* Is it `$*' or `$@' (unquoted) ? */
+      else if (*env == '*' || (*env == '@' && !quoted))
+	{
+	  size_t plist_len = 0;
+	  int p;
+	  char *end;
+
+	  /* Build up value parameter by parameter (copy them) */
+	  for (p = 1; __libc_argv[p]; ++p)
+	    plist_len += strlen (__libc_argv[p]) + 1; /* for space */
+	  value = malloc (plist_len);
+	  if (value == NULL)
+	    goto no_space;
+	  end = value;
+	  *end = 0;
+	  for (p = 1; __libc_argv[p]; ++p)
+	    {
+	      if (p > 1)
+		*end++ = ' ';
+	      end = __stpcpy (end, __libc_argv[p]);
+	    }
+
+	  free_value = 1;
+	}
+      else
+	{
+	  /* Must be a quoted `$@' */
+	  assert (*env == '@' && quoted);
+
+	  /* Each parameter is a separate word ("$@") */
+	  if (__libc_argc == 2)
+	    value = __libc_argv[1];
+	  else if (__libc_argc > 2)
+	    {
+	      int p;
+
+	      /* Append first parameter to current word. */
+	      value = w_addstr (*word, word_length, max_length,
+				__libc_argv[1]);
+	      if (value == NULL || w_addword (pwordexp, value))
+		goto no_space;
+
+	      for (p = 2; __libc_argv[p + 1]; p++)
+		{
+		  char *newword = __strdup (__libc_argv[p]);
+		  if (newword == NULL || w_addword (pwordexp, newword))
+		    goto no_space;
+		}
+
+	      /* Start a new word with the last parameter. */
+	      *word = w_newword (word_length, max_length);
+	      value = __libc_argv[p];
+	    }
+	  else
+	    {
+	      free (env);
+	      free (pattern);
+	      return 0;
+	    }
+	}
+    }
+  else
+    value = getenv (env);
+
+  if (value == NULL && (flags & WRDE_UNDEF))
+    {
+      /* Variable not defined. */
+      error = WRDE_BADVAL;
+      goto do_error;
+    }
+
+  if (action != ACT_NONE)
+    {
+      int expand_pattern = 0;
+
+      /* First, find out if we need to expand pattern (i.e. if we will
+       * use it). */
+      switch (action)
+	{
+	case ACT_RP_SHORT_LEFT:
+	case ACT_RP_LONG_LEFT:
+	case ACT_RP_SHORT_RIGHT:
+	case ACT_RP_LONG_RIGHT:
+	  /* Always expand for these. */
+	  expand_pattern = 1;
+	  break;
+
+	case ACT_NULL_ERROR:
+	case ACT_NULL_SUBST:
+	case ACT_NULL_ASSIGN:
+	  if (!value || (!*value && colon_seen))
+	    /* If param is unset, or set but null and a colon has been seen,
+	       the expansion of the pattern will be needed. */
+	    expand_pattern = 1;
+
+	  break;
+
+	case ACT_NONNULL_SUBST:
+	  /* Expansion of word will be needed if parameter is set and not null,
+	     or set null but no colon has been seen. */
+	  if (value && (*value || !colon_seen))
+	    expand_pattern = 1;
+
+	  break;
+
+	default:
+	  assert (! "Unrecognised action!");
+	}
+
+      if (expand_pattern)
+	{
+	  /* We need to perform tilde expansion, parameter expansion,
+             command substitution, and arithmetic expansion.  We also
+	     have to be a bit careful with wildcard characters, as
+	     pattern might be given to fnmatch soon.  To do this, we
+	     convert quotes to escapes. */
+
+	  char *expanded;
+	  size_t exp_len;
+	  size_t exp_maxl;
+	  char *p;
+	  int quoted = 0; /* 1: single quotes; 2: double */
+
+	  expanded = w_newword (&exp_len, &exp_maxl);
+	  for (p = pattern; p && *p; p++)
+	    {
+	      size_t offset;
+
+	      switch (*p)
+		{
+		case '"':
+		  if (quoted == 2)
+		    quoted = 0;
+		  else if (quoted == 0)
+		    quoted = 2;
+		  else break;
+
+		  continue;
+
+		case '\'':
+		  if (quoted == 1)
+		    quoted = 0;
+		  else if (quoted == 0)
+		    quoted = 1;
+		  else break;
+
+		  continue;
+
+		case '*':
+		case '?':
+		  if (quoted)
+		    {
+		      /* Convert quoted wildchar to escaped wildchar. */
+		      expanded = w_addchar (expanded, &exp_len,
+					    &exp_maxl, '\\');
+
+		      if (expanded == NULL)
+			goto no_space;
+		    }
+		  break;
+
+		case '$':
+		  offset = 0;
+		  error = parse_dollars (&expanded, &exp_len, &exp_maxl, p,
+					 &offset, flags, NULL, NULL, NULL, 1);
+		  if (error)
+		    {
+		      if (free_value)
+			free (value);
+
+		      if (expanded)
+			free (expanded);
+
+		      goto do_error;
+		    }
+
+		  p += offset;
+		  continue;
+
+		case '~':
+		  if (quoted || exp_len)
+		    break;
+
+		  offset = 0;
+		  error = parse_tilde (&expanded, &exp_len, &exp_maxl, p,
+				       &offset, 0);
+		  if (error)
+		    {
+		      if (free_value)
+			free (value);
+
+		      if (expanded)
+			free (expanded);
+
+		      goto do_error;
+		    }
+
+		  p += offset;
+		  continue;
+
+		case '\\':
+		  expanded = w_addchar (expanded, &exp_len, &exp_maxl, '\\');
+		  ++p;
+		  assert (*p); /* checked when extracted initially */
+		  if (expanded == NULL)
+		    goto no_space;
+		}
+
+	      expanded = w_addchar (expanded, &exp_len, &exp_maxl, *p);
+
+	      if (expanded == NULL)
+		goto no_space;
+	    }
+
+	  if (pattern)
+		  free (pattern);
+
+	  pattern = expanded;
+	}
+
+      switch (action)
+	{
+	case ACT_RP_SHORT_LEFT:
+	case ACT_RP_LONG_LEFT:
+	case ACT_RP_SHORT_RIGHT:
+	case ACT_RP_LONG_RIGHT:
+	  {
+	    char *p;
+	    char c;
+	    char *end;
+
+	    if (value == NULL || pattern == NULL || *pattern == '\0')
+	      break;
+
+	    end = value + strlen (value);
+
+	    switch (action)
+	      {
+	      case ACT_RP_SHORT_LEFT:
+		for (p = value; p <= end; ++p)
+		  {
+		    c = *p;
+		    *p = '\0';
+		    if (fnmatch (pattern, value, 0) != FNM_NOMATCH)
+		      {
+			*p = c;
+			if (free_value)
+			  {
+			    char *newval = __strdup (p);
+			    if (newval == NULL)
+			      {
+				free (value);
+				goto no_space;
+			      }
+			    free (value);
+			    value = newval;
+			  }
+			else
+			  value = p;
+			break;
+		      }
+		    *p = c;
+		  }
+
+		break;
+
+	      case ACT_RP_LONG_LEFT:
+		for (p = end; p >= value; --p)
+		  {
+		    c = *p;
+		    *p = '\0';
+		    if (fnmatch (pattern, value, 0) != FNM_NOMATCH)
+		      {
+			*p = c;
+			if (free_value)
+			  {
+			    char *newval = __strdup (p);
+			    if (newval == NULL)
+			      {
+				free (value);
+				goto no_space;
+			      }
+			    free (value);
+			    value = newval;
+			  }
+			else
+			  value = p;
+			break;
+		      }
+		    *p = c;
+		  }
+
+		break;
+
+	      case ACT_RP_SHORT_RIGHT:
+		for (p = end; p >= value; --p)
+		  {
+		    if (fnmatch (pattern, p, 0) != FNM_NOMATCH)
+		      {
+			char *newval;
+			newval = malloc (p - value + 1);
+
+			if (newval == NULL)
+			  {
+			    if (free_value)
+			      free (value);
+			    goto no_space;
+			  }
+
+			*(char *) __mempcpy (newval, value, p - value) = '\0';
+			if (free_value)
+			  free (value);
+			value = newval;
+			free_value = 1;
+			break;
+		      }
+		  }
+
+		break;
+
+	      case ACT_RP_LONG_RIGHT:
+		for (p = value; p <= end; ++p)
+		  {
+		    if (fnmatch (pattern, p, 0) != FNM_NOMATCH)
+		      {
+			char *newval;
+			newval = malloc (p - value + 1);
+
+			if (newval == NULL)
+			  {
+			    if (free_value)
+			      free (value);
+			    goto no_space;
+			  }
+
+			*(char *) __mempcpy (newval, value, p - value) = '\0';
+			if (free_value)
+			  free (value);
+			value = newval;
+			free_value = 1;
+			break;
+		      }
+		  }
+
+		break;
+
+	      default:
+		break;
+	      }
+
+	    break;
+	  }
+
+	case ACT_NULL_ERROR:
+	  if (value && *value)
+	    /* Substitute parameter */
+	    break;
+
+	  error = 0;
+	  if (!colon_seen && value)
+	    /* Substitute NULL */
+	    ;
+	  else
+	    {
+	      const char *str = pattern;
+
+	      if (str[0] == '\0')
+		str = _("parameter null or not set");
+
+	      __fxprintf (NULL, "%s: %s\n", env, str);
+	    }
+
+	  if (free_value)
+	    free (value);
+	  goto do_error;
+
+	case ACT_NULL_SUBST:
+	  if (value && *value)
+	    /* Substitute parameter */
+	    break;
+
+	  if (free_value && value)
+	    free (value);
+
+	  if (!colon_seen && value)
+	    /* Substitute NULL */
+	    goto success;
+
+	  value = pattern ? __strdup (pattern) : pattern;
+	  free_value = 1;
+
+	  if (pattern && !value)
+	    goto no_space;
+
+	  break;
+
+	case ACT_NONNULL_SUBST:
+	  if (value && (*value || !colon_seen))
+	    {
+	      if (free_value && value)
+		free (value);
+
+	      value = pattern ? __strdup (pattern) : pattern;
+	      free_value = 1;
+
+	      if (pattern && !value)
+		goto no_space;
+
+	      break;
+	    }
+
+	  /* Substitute NULL */
+	  if (free_value)
+	    free (value);
+	  goto success;
+
+	case ACT_NULL_ASSIGN:
+	  if (value && *value)
+	    /* Substitute parameter */
+	    break;
+
+	  if (!colon_seen && value)
+	    {
+	      /* Substitute NULL */
+	      if (free_value)
+		free (value);
+	      goto success;
+	    }
+
+	  if (free_value && value)
+	    free (value);
+
+	  value = pattern ? __strdup (pattern) : pattern;
+	  free_value = 1;
+
+	  if (pattern && !value)
+	    goto no_space;
+
+	  __setenv (env, value, 1);
+	  break;
+
+	default:
+	  assert (! "Unrecognised action!");
+	}
+    }
+
+  free (env); env = NULL;
+  free (pattern); pattern = NULL;
+
+  if (seen_hash)
+    {
+      char param_length[21];
+      param_length[20] = '\0';
+      *word = w_addstr (*word, word_length, max_length,
+			_itoa_word (value ? strlen (value) : 0,
+				    &param_length[20], 10, 0));
+      if (free_value)
+	{
+	  assert (value != NULL);
+	  free (value);
+	}
+
+      return *word ? 0 : WRDE_NOSPACE;
+    }
+
+  if (value == NULL)
+    return 0;
+
+  if (quoted || !pwordexp)
+    {
+      /* Quoted - no field split */
+      *word = w_addstr (*word, word_length, max_length, value);
+      if (free_value)
+	free (value);
+
+      return *word ? 0 : WRDE_NOSPACE;
+    }
+  else
+    {
+      /* Need to field-split */
+      char *value_copy = __strdup (value); /* Don't modify value */
+      char *field_begin = value_copy;
+      int seen_nonws_ifs = 0;
+
+      if (free_value)
+	free (value);
+
+      if (value_copy == NULL)
+	goto no_space;
+
+      do
+	{
+	  char *field_end = field_begin;
+	  char *next_field;
+
+	  /* If this isn't the first field, start a new word */
+	  if (field_begin != value_copy)
+	    {
+	      if (w_addword (pwordexp, *word) == WRDE_NOSPACE)
+		{
+		  free (value_copy);
+		  goto no_space;
+		}
+
+	      *word = w_newword (word_length, max_length);
+	    }
+
+	  /* Skip IFS whitespace before the field */
+	  field_begin += strspn (field_begin, ifs_white);
+
+	  if (!seen_nonws_ifs && *field_begin == 0)
+	    /* Nothing but whitespace */
+	    break;
+
+	  /* Search for the end of the field */
+	  field_end = field_begin + strcspn (field_begin, ifs);
+
+	  /* Set up pointer to the character after end of field and
+             skip whitespace IFS after it. */
+	  next_field = field_end + strspn (field_end, ifs_white);
+
+	  /* Skip at most one non-whitespace IFS character after the field */
+	  seen_nonws_ifs = 0;
+	  if (*next_field && strchr (ifs, *next_field))
+	    {
+	      seen_nonws_ifs = 1;
+	      next_field++;
+	    }
+
+	  /* Null-terminate it */
+	  *field_end = 0;
+
+	  /* Tag a copy onto the current word */
+	  *word = w_addstr (*word, word_length, max_length, field_begin);
+
+	  if (*word == NULL && *field_begin != '\0')
+	    {
+	      free (value_copy);
+	      goto no_space;
+	    }
+
+	  field_begin = next_field;
+	}
+      while (seen_nonws_ifs || *field_begin);
+
+      free (value_copy);
+    }
+
+  return 0;
+
+success:
+  error = 0;
+  goto do_error;
+
+no_space:
+  error = WRDE_NOSPACE;
+  goto do_error;
+
+syntax:
+  error = WRDE_SYNTAX;
+
+do_error:
+  if (env)
+    free (env);
+
+  if (pattern)
+    free (pattern);
+
+  return error;
+}
+
+static int
+internal_function
+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)
+{
+  /* We are poised _at_ "$" */
+  switch (words[1 + *offset])
+    {
+    case '"':
+    case '\'':
+    case 0:
+      *word = w_addchar (*word, word_length, max_length, '$');
+      return *word ? 0 : WRDE_NOSPACE;
+
+    case '(':
+      if (words[2 + *offset] == '(')
+	{
+	  /* Differentiate between $((1+3)) and $((echo);(ls)) */
+	  int i = 3 + *offset;
+	  int depth = 0;
+	  while (words[i] && !(depth == 0 && words[i] == ')'))
+	    {
+	      if (words[i] == '(')
+		++depth;
+	      else if (words[i] == ')')
+		--depth;
+
+	      ++i;
+	    }
+
+	  if (words[i] == ')' && words[i + 1] == ')')
+	    {
+	      (*offset) += 3;
+	      /* Call parse_arith -- 0 is for "no brackets" */
+	      return parse_arith (word, word_length, max_length, words, offset,
+				  flags, 0);
+	    }
+	}
+
+      if (flags & WRDE_NOCMD)
+	return WRDE_CMDSUB;
+
+      (*offset) += 2;
+      return parse_comm (word, word_length, max_length, words, offset, flags,
+			 quoted? NULL : pwordexp, ifs, ifs_white);
+
+    case '[':
+      (*offset) += 2;
+      /* Call parse_arith -- 1 is for "brackets" */
+      return parse_arith (word, word_length, max_length, words, offset, flags,
+			  1);
+
+    case '{':
+    default:
+      ++(*offset);	/* parse_param needs to know if "{" is there */
+      return parse_param (word, word_length, max_length, words, offset, flags,
+			   pwordexp, ifs, ifs_white, quoted);
+    }
+}
+
+static int
+internal_function
+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)
+{
+  /* We are poised just after "`" */
+  int error;
+  int squoting = 0;
+  size_t comm_length;
+  size_t comm_maxlen;
+  char *comm = w_newword (&comm_length, &comm_maxlen);
+
+  for (; words[*offset]; ++(*offset))
+    {
+      switch (words[*offset])
+	{
+	case '`':
+	  /* Go -- give the script to the shell */
+	  error = exec_comm (comm, word, word_length, max_length, flags,
+			     pwordexp, ifs, ifs_white);
+	  free (comm);
+	  return error;
+
+	case '\\':
+	  if (squoting)
+	    {
+	      error = parse_qtd_backslash (&comm, &comm_length, &comm_maxlen,
+					   words, offset);
+
+	      if (error)
+		{
+		  free (comm);
+		  return error;
+		}
+
+	      break;
+	    }
+
+	  ++(*offset);
+	  error = parse_backslash (&comm, &comm_length, &comm_maxlen, words,
+				   offset);
+
+	  if (error)
+	    {
+	      free (comm);
+	      return error;
+	    }
+
+	  break;
+
+	case '\'':
+	  squoting = 1 - squoting;
+	default:
+	  comm = w_addchar (comm, &comm_length, &comm_maxlen, words[*offset]);
+	  if (comm == NULL)
+	    return WRDE_NOSPACE;
+	}
+    }
+
+  /* Premature end */
+  free (comm);
+  return WRDE_SYNTAX;
+}
+
+static int
+internal_function
+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)
+{
+  /* We are poised just after a double-quote */
+  int error;
+
+  for (; words[*offset]; ++(*offset))
+    {
+      switch (words[*offset])
+	{
+	case '"':
+	  return 0;
+
+	case '$':
+	  error = parse_dollars (word, word_length, max_length, words, offset,
+				 flags, pwordexp, ifs, ifs_white, 1);
+	  /* The ``1'' here is to tell parse_dollars not to
+	   * split the fields.  It may need to, however ("$@").
+	   */
+	  if (error)
+	    return error;
+
+	  break;
+
+	case '`':
+	  if (flags & WRDE_NOCMD)
+	    return WRDE_CMDSUB;
+
+	  ++(*offset);
+	  error = parse_backtick (word, word_length, max_length, words,
+				  offset, flags, NULL, NULL, NULL);
+	  /* The first NULL here is to tell parse_backtick not to
+	   * split the fields.
+	   */
+	  if (error)
+	    return error;
+
+	  break;
+
+	case '\\':
+	  error = parse_qtd_backslash (word, word_length, max_length, words,
+				       offset);
+
+	  if (error)
+	    return error;
+
+	  break;
+
+	default:
+	  *word = w_addchar (*word, word_length, max_length, words[*offset]);
+	  if (*word == NULL)
+	    return WRDE_NOSPACE;
+	}
+    }
+
+  /* Unterminated string */
+  return WRDE_SYNTAX;
+}
+
+/*
+ * wordfree() is to be called after pwordexp is finished with.
+ */
+
+void
+wordfree (wordexp_t *pwordexp)
+{
+
+  /* wordexp can set pwordexp to NULL */
+  if (pwordexp && pwordexp->we_wordv)
+    {
+      char **wordv = pwordexp->we_wordv;
+
+      for (wordv += pwordexp->we_offs; *wordv; ++wordv)
+	free (*wordv);
+
+      free (pwordexp->we_wordv);
+      pwordexp->we_wordv = NULL;
+    }
+}
+libc_hidden_def (wordfree)
+
+/*
+ * wordexp()
+ */
+
+int
+wordexp (const char *words, wordexp_t *pwordexp, int flags)
+{
+  size_t words_offset;
+  size_t word_length;
+  size_t max_length;
+  char *word = w_newword (&word_length, &max_length);
+  int error;
+  char *ifs;
+  char ifs_white[4];
+  wordexp_t old_word = *pwordexp;
+
+  if (flags & WRDE_REUSE)
+    {
+      /* Minimal implementation of WRDE_REUSE for now */
+      wordfree (pwordexp);
+      old_word.we_wordv = NULL;
+    }
+
+  if ((flags & WRDE_APPEND) == 0)
+    {
+      pwordexp->we_wordc = 0;
+
+      if (flags & WRDE_DOOFFS)
+	{
+	  pwordexp->we_wordv = calloc (1 + pwordexp->we_offs, sizeof (char *));
+	  if (pwordexp->we_wordv == NULL)
+	    {
+	      error = WRDE_NOSPACE;
+	      goto do_error;
+	    }
+	}
+      else
+	{
+	  pwordexp->we_wordv = calloc (1, sizeof (char *));
+	  if (pwordexp->we_wordv == NULL)
+	    {
+	      error = WRDE_NOSPACE;
+	      goto do_error;
+	    }
+
+	  pwordexp->we_offs = 0;
+	}
+    }
+
+  /* Find out what the field separators are.
+   * There are two types: whitespace and non-whitespace.
+   */
+  ifs = getenv ("IFS");
+
+  if (!ifs)
+    /* IFS unset - use <space><tab><newline>. */
+    ifs = strcpy (ifs_white, " \t\n");
+  else
+    {
+      char *ifsch = ifs;
+      char *whch = ifs_white;
+
+      /* Start off with no whitespace IFS characters */
+      ifs_white[0] = '\0';
+
+      while (*ifsch != '\0')
+	{
+	  if ((*ifsch == ' ') || (*ifsch == '\t') || (*ifsch == '\n'))
+	    {
+	      /* Whitespace IFS.  See first whether it is already in our
+		 collection.  */
+	      char *runp = ifs_white;
+
+	      while (runp < whch && *runp != '\0' && *runp != *ifsch)
+		++runp;
+
+	      if (runp == whch)
+		*whch++ = *ifsch;
+	    }
+
+	  ++ifsch;
+	}
+      *whch = '\0';
+    }
+
+  for (words_offset = 0 ; words[words_offset] ; ++words_offset)
+    switch (words[words_offset])
+      {
+      case '\\':
+	error = parse_backslash (&word, &word_length, &max_length, words,
+				 &words_offset);
+
+	if (error)
+	  goto do_error;
+
+	break;
+
+      case '$':
+	error = parse_dollars (&word, &word_length, &max_length, words,
+			       &words_offset, flags, pwordexp, ifs, ifs_white,
+			       0);
+
+	if (error)
+	  goto do_error;
+
+	break;
+
+      case '`':
+	if (flags & WRDE_NOCMD)
+	  {
+	    error = WRDE_CMDSUB;
+	    goto do_error;
+	  }
+
+	++words_offset;
+	error = parse_backtick (&word, &word_length, &max_length, words,
+				&words_offset, flags, pwordexp, ifs,
+				ifs_white);
+
+	if (error)
+	  goto do_error;
+
+	break;
+
+      case '"':
+	++words_offset;
+	error = parse_dquote (&word, &word_length, &max_length, words,
+			      &words_offset, flags, pwordexp, ifs, ifs_white);
+
+	if (error)
+	  goto do_error;
+
+	if (!word_length)
+	  {
+	    error = w_addword (pwordexp, NULL);
+
+	    if (error)
+	      return error;
+	  }
+
+	break;
+
+      case '\'':
+	++words_offset;
+	error = parse_squote (&word, &word_length, &max_length, words,
+			      &words_offset);
+
+	if (error)
+	  goto do_error;
+
+	if (!word_length)
+	  {
+	    error = w_addword (pwordexp, NULL);
+
+	    if (error)
+	      return error;
+	  }
+
+	break;
+
+      case '~':
+	error = parse_tilde (&word, &word_length, &max_length, words,
+			     &words_offset, pwordexp->we_wordc);
+
+	if (error)
+	  goto do_error;
+
+	break;
+
+      case '*':
+      case '[':
+      case '?':
+	error = parse_glob (&word, &word_length, &max_length, words,
+			    &words_offset, flags, pwordexp, ifs, ifs_white);
+
+	if (error)
+	  goto do_error;
+
+	break;
+
+      default:
+	/* Is it a word separator? */
+	if (strchr (" \t", words[words_offset]) == NULL)
+	  {
+	    char ch = words[words_offset];
+
+	    /* Not a word separator -- but is it a valid word char? */
+	    if (strchr ("\n|&;<>(){}", ch))
+	      {
+		/* Fail */
+		error = WRDE_BADCHAR;
+		goto do_error;
+	      }
+
+	    /* "Ordinary" character -- add it to word */
+	    word = w_addchar (word, &word_length, &max_length,
+			      ch);
+	    if (word == NULL)
+	      {
+		error = WRDE_NOSPACE;
+		goto do_error;
+	      }
+
+	    break;
+	  }
+
+	/* If a word has been delimited, add it to the list. */
+	if (word != NULL)
+	  {
+	    error = w_addword (pwordexp, word);
+	    if (error)
+	      goto do_error;
+	  }
+
+	word = w_newword (&word_length, &max_length);
+      }
+
+  /* End of string */
+
+  /* There was a word separator at the end */
+  if (word == NULL) /* i.e. w_newword */
+    return 0;
+
+  /* There was no field separator at the end */
+  return w_addword (pwordexp, word);
+
+do_error:
+  /* Error:
+   *	free memory used (unless error is WRDE_NOSPACE), and
+   *	set pwordexp members back to what they were.
+   */
+
+  if (word != NULL)
+    free (word);
+
+  if (error == WRDE_NOSPACE)
+    return WRDE_NOSPACE;
+
+  if ((flags & WRDE_APPEND) == 0)
+    wordfree (pwordexp);
+
+  *pwordexp = old_word;
+  return error;
+}