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-rw-r--r--texinfo/info/tilde.c376
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diff --git a/texinfo/info/tilde.c b/texinfo/info/tilde.c
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+/* tilde.c -- Tilde expansion code (~/foo := $HOME/foo).
+ $Id: tilde.c,v 1.1 1997/08/21 22:58:05 jason Exp $
+
+ This file is part of GNU Info, a program for reading online documentation
+ stored in Info format.
+
+ Copyright (C) 1988, 89, 90, 91, 92, 93, 96 Free Software Foundation, Inc.
+
+ This program 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 2, or (at your option)
+ any later version.
+
+ This program 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 this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+ Written by Brian Fox (bfox@ai.mit.edu). */
+
+#if defined (__GNUC__)
+# define alloca __builtin_alloca
+#else /* !__GNUC__ */
+# if defined (_AIX)
+ #pragma alloca
+# else /* !_AIX */
+# if defined (HAVE_ALLOCA_H)
+# include <alloca.h>
+# endif /* HAVE_ALLOCA_H */
+# endif /* !AIX */
+#endif /* !__GNUC__ */
+
+#if defined (HAVE_STDLIB_H)
+#include <stdlib.h>
+#endif
+
+#include "tilde.h"
+#include <pwd.h>
+
+#if defined (HAVE_STRING_H)
+#include <string.h>
+#endif
+
+#include "clib.h"
+
+#if !defined (NULL)
+# define NULL 0x0
+#endif
+
+#if defined (TEST) || defined (STATIC_MALLOC)
+static void *xmalloc (), *xrealloc ();
+#else
+extern void *xmalloc (), *xrealloc ();
+#endif /* TEST || STATIC_MALLOC */
+
+/* The default value of tilde_additional_prefixes. This is set to
+ whitespace preceding a tilde so that simple programs which do not
+ perform any word separation get desired behaviour. */
+static char *default_prefixes[] =
+ { " ~", "\t~", (char *)NULL };
+
+/* The default value of tilde_additional_suffixes. This is set to
+ whitespace or newline so that simple programs which do not
+ perform any word separation get desired behaviour. */
+static char *default_suffixes[] =
+ { " ", "\n", (char *)NULL };
+
+/* If non-null, this contains the address of a function to call if the
+ standard meaning for expanding a tilde fails. The function is called
+ with the text (sans tilde, as in "foo"), and returns a malloc()'ed string
+ which is the expansion, or a NULL pointer if there is no expansion. */
+CFunction *tilde_expansion_failure_hook = (CFunction *)NULL;
+
+/* When non-null, this is a NULL terminated array of strings which
+ are duplicates for a tilde prefix. Bash uses this to expand
+ `=~' and `:~'. */
+char **tilde_additional_prefixes = default_prefixes;
+
+/* When non-null, this is a NULL terminated array of strings which match
+ the end of a username, instead of just "/". Bash sets this to
+ `:' and `=~'. */
+char **tilde_additional_suffixes = default_suffixes;
+
+/* Find the start of a tilde expansion in STRING, and return the index of
+ the tilde which starts the expansion. Place the length of the text
+ which identified this tilde starter in LEN, excluding the tilde itself. */
+static int
+tilde_find_prefix (string, len)
+ char *string;
+ int *len;
+{
+ register int i, j, string_len;
+ register char **prefixes = tilde_additional_prefixes;
+
+ string_len = strlen (string);
+ *len = 0;
+
+ if (!*string || *string == '~')
+ return (0);
+
+ if (prefixes)
+ {
+ for (i = 0; i < string_len; i++)
+ {
+ for (j = 0; prefixes[j]; j++)
+ {
+ if (strncmp (string + i, prefixes[j], strlen (prefixes[j])) == 0)
+ {
+ *len = strlen (prefixes[j]) - 1;
+ return (i + *len);
+ }
+ }
+ }
+ }
+ return (string_len);
+}
+
+/* Find the end of a tilde expansion in STRING, and return the index of
+ the character which ends the tilde definition. */
+static int
+tilde_find_suffix (string)
+ char *string;
+{
+ register int i, j, string_len;
+ register char **suffixes = tilde_additional_suffixes;
+
+ string_len = strlen (string);
+
+ for (i = 0; i < string_len; i++)
+ {
+ if (string[i] == '/' || !string[i])
+ break;
+
+ for (j = 0; suffixes && suffixes[j]; j++)
+ {
+ if (strncmp (string + i, suffixes[j], strlen (suffixes[j])) == 0)
+ return (i);
+ }
+ }
+ return (i);
+}
+
+/* Return a new string which is the result of tilde expanding STRING. */
+char *
+tilde_expand (string)
+ char *string;
+{
+ char *result, *tilde_expand_word ();
+ int result_size, result_index;
+
+ result_size = result_index = 0;
+ result = (char *)NULL;
+
+ /* Scan through STRING expanding tildes as we come to them. */
+ while (1)
+ {
+ register int start, end;
+ char *tilde_word, *expansion;
+ int len;
+
+ /* Make START point to the tilde which starts the expansion. */
+ start = tilde_find_prefix (string, &len);
+
+ /* Copy the skipped text into the result. */
+ if ((result_index + start + 1) > result_size)
+ result = (char *)xrealloc (result, 1 + (result_size += (start + 20)));
+
+ strncpy (result + result_index, string, start);
+ result_index += start;
+
+ /* Advance STRING to the starting tilde. */
+ string += start;
+
+ /* Make END be the index of one after the last character of the
+ username. */
+ end = tilde_find_suffix (string);
+
+ /* If both START and END are zero, we are all done. */
+ if (!start && !end)
+ break;
+
+ /* Expand the entire tilde word, and copy it into RESULT. */
+ tilde_word = (char *)xmalloc (1 + end);
+ strncpy (tilde_word, string, end);
+ tilde_word[end] = '\0';
+ string += end;
+
+ expansion = tilde_expand_word (tilde_word);
+ free (tilde_word);
+
+ len = strlen (expansion);
+ if ((result_index + len + 1) > result_size)
+ result = (char *)xrealloc (result, 1 + (result_size += (len + 20)));
+
+ strcpy (result + result_index, expansion);
+ result_index += len;
+ free (expansion);
+ }
+
+ result[result_index] = '\0';
+
+ return (result);
+}
+
+/* Do the work of tilde expansion on FILENAME. FILENAME starts with a
+ tilde. If there is no expansion, call tilde_expansion_failure_hook. */
+char *
+tilde_expand_word (filename)
+ char *filename;
+{
+ char *dirname;
+
+ dirname = filename ? strdup (filename) : (char *)NULL;
+
+ if (dirname && *dirname == '~')
+ {
+ char *temp_name;
+ if (!dirname[1] || dirname[1] == '/')
+ {
+ /* Prepend $HOME to the rest of the string. */
+ extern char *getenv ();
+ char *temp_home = getenv ("HOME");
+
+ /* If there is no HOME variable, look up the directory in
+ the password database. */
+ if (!temp_home)
+ {
+ struct passwd *entry;
+
+ entry = (struct passwd *) getpwuid (getuid ());
+ if (entry)
+ temp_home = entry->pw_dir;
+ }
+
+ temp_name = (char *)
+ alloca (1 + strlen (&dirname[1])
+ + (temp_home ? strlen (temp_home) : 0));
+ temp_name[0] = '\0';
+ if (temp_home)
+ strcpy (temp_name, temp_home);
+ strcat (temp_name, &dirname[1]);
+ free (dirname);
+ dirname = strdup (temp_name);
+ }
+ else
+ {
+ struct passwd *user_entry;
+ char *username = (char *)alloca (257);
+ int i, c;
+
+ for (i = 1; c = dirname[i]; i++)
+ {
+ if (c == '/')
+ break;
+ else
+ username[i - 1] = c;
+ }
+ username[i - 1] = '\0';
+
+ if (!(user_entry = (struct passwd *) getpwnam (username)))
+ {
+ /* If the calling program has a special syntax for
+ expanding tildes, and we couldn't find a standard
+ expansion, then let them try. */
+ if (tilde_expansion_failure_hook)
+ {
+ char *expansion;
+
+ expansion = (*tilde_expansion_failure_hook) (username);
+
+ if (expansion)
+ {
+ temp_name = (char *)alloca
+ (1 + strlen (expansion) + strlen (&dirname[i]));
+ strcpy (temp_name, expansion);
+ strcat (temp_name, &dirname[i]);
+ free (expansion);
+ goto return_name;
+ }
+ }
+ /* We shouldn't report errors. */
+ }
+ else
+ {
+ temp_name = (char *)alloca
+ (1 + strlen (user_entry->pw_dir) + strlen (&dirname[i]));
+ strcpy (temp_name, user_entry->pw_dir);
+ strcat (temp_name, &dirname[i]);
+ return_name:
+ free (dirname);
+ dirname = strdup (temp_name);
+ }
+ endpwent ();
+ }
+ }
+ return (dirname);
+}
+
+
+#if defined (TEST)
+#undef NULL
+#include <stdio.h>
+
+main (argc, argv)
+ int argc;
+ char **argv;
+{
+ char *result, line[512];
+ int done = 0;
+
+ while (!done)
+ {
+ printf ("~expand: ");
+ fflush (stdout);
+
+ if (!gets (line))
+ strcpy (line, "done");
+
+ if ((strcmp (line, "done") == 0) ||
+ (strcmp (line, "quit") == 0) ||
+ (strcmp (line, "exit") == 0))
+ {
+ done = 1;
+ break;
+ }
+
+ result = tilde_expand (line);
+ printf (" --> %s\n", result);
+ free (result);
+ }
+ exit (0);
+}
+
+static void memory_error_and_abort ();
+
+static void *
+xmalloc (bytes)
+ int bytes;
+{
+ void *temp = (void *)malloc (bytes);
+
+ if (!temp)
+ memory_error_and_abort ();
+ return (temp);
+}
+
+static void *
+xrealloc (pointer, bytes)
+ void *pointer;
+ int bytes;
+{
+ void *temp;
+
+ if (!pointer)
+ temp = (char *)malloc (bytes);
+ else
+ temp = (char *)realloc (pointer, bytes);
+
+ if (!temp)
+ memory_error_and_abort ();
+
+ return (temp);
+}
+
+static void
+memory_error_and_abort ()
+{
+ fprintf (stderr, "readline: Out of virtual memory!\n");
+ abort ();
+}
+#endif /* TEST */
+
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