1 /* hashcmd.c - functions for managing a hash table mapping command names to
4 /* Copyright (C) 1997 Free Software Foundation, Inc.
6 This file is part of GNU Bash, the Bourne Again SHell.
8 Bash is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 1, or (at your option) any later
13 Bash is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License along
19 with Bash; see the file COPYING. If not, write to the Free Software
20 Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
24 #include "bashtypes.h"
25 #include "posixstat.h"
27 #if defined (HAVE_UNISTD_H)
34 #include "execute_cmd.h"
37 extern int hashing_enabled;
39 static int hashing_initialized = 0;
41 HASH_TABLE *hashed_filenames;
44 initialize_filename_hashing ()
46 if (hashing_initialized == 0)
48 hashed_filenames = make_hash_table (FILENAME_HASH_BUCKETS);
49 hashing_initialized = 1;
54 free_filename_data (data)
57 free (((PATH_DATA *)data)->path);
62 flush_hashed_filenames ()
65 flush_hash_table (hashed_filenames, free_filename_data);
68 /* Remove FILENAME from the table of hashed commands. */
70 remove_hashed_filename (filename)
73 register BUCKET_CONTENTS *item;
75 if (hashing_enabled == 0 || hashed_filenames == 0)
78 item = remove_hash_item (filename, hashed_filenames);
82 free_filename_data (item->data);
88 /* Place FILENAME (key) and FULL_PATHNAME (data->path) into the
89 hash table. CHECK_DOT if non-null is for future calls to
90 find_hashed_filename (); it means that this file was found
91 in a directory in $PATH that is not an absolute pathname.
92 FOUND is the initial value for times_found. */
94 remember_filename (filename, full_pathname, check_dot, found)
95 char *filename, *full_pathname;
98 register BUCKET_CONTENTS *item;
100 if (hashing_enabled == 0)
103 if (hashed_filenames == 0 || hashing_initialized == 0)
104 initialize_filename_hashing ();
106 item = add_hash_item (filename, hashed_filenames);
108 free (pathdata(item)->path);
111 item->key = savestring (filename);
112 item->data = xmalloc (sizeof (PATH_DATA));
114 pathdata(item)->path = savestring (full_pathname);
115 pathdata(item)->flags = 0;
117 pathdata(item)->flags |= HASH_CHKDOT;
118 if (*full_pathname != '/')
119 pathdata(item)->flags |= HASH_RELPATH;
120 item->times_found = found;
123 /* Return the full pathname that FILENAME hashes to. If FILENAME
124 is hashed, but (data->flags & HASH_CHKDOT) is non-zero, check
125 ./FILENAME and return that if it is executable. This always
126 returns a newly-allocated string; the caller is responsible
129 find_hashed_filename (filename)
132 register BUCKET_CONTENTS *item;
133 char *path, *dotted_filename, *tail;
136 if (hashing_enabled == 0 || hashed_filenames == 0)
137 return ((char *)NULL);
139 item = find_hash_item (filename, hashed_filenames);
142 return ((char *)NULL);
144 /* If this filename is hashed, but `.' comes before it in the path,
145 see if ./filename is executable. If the hashed value is not an
146 absolute pathname, see if ./`hashed-value' exists. */
147 path = pathdata(item)->path;
148 if (pathdata(item)->flags & (HASH_CHKDOT|HASH_RELPATH))
150 tail = (pathdata(item)->flags & HASH_RELPATH) ? path : filename;
151 dotted_filename = xmalloc (3 + strlen (tail));
152 dotted_filename[0] = '.'; dotted_filename[1] = '/';
153 strcpy (dotted_filename + 2, tail);
155 if (executable_file (dotted_filename))
156 return (dotted_filename);
158 free (dotted_filename);
161 if (pathdata(item)->flags & HASH_RELPATH)
162 return ((char *)NULL);
165 /* Watch out. If this file was hashed to "./filename", and
166 "./filename" is not executable, then return NULL. */
168 /* Since we already know "./filename" is not executable, what
169 we're really interested in is whether or not the `path'
170 portion of the hashed filename is equivalent to the current
171 directory, but only if it starts with a `.'. (This catches
172 ./. and so on.) same_file () tests general Unix file
173 equivalence -- same device and inode. */
177 tail = (char *)strrchr (path, '/');
182 same = same_file (".", path, (struct stat *)NULL, (struct stat *)NULL);
186 return same ? (char *)NULL : savestring (path);
190 return (savestring (path));