1/* hashcmd.c - functions for managing a hash table mapping command names to 2 full pathnames. */ 3 4/* Copyright (C) 1997-2009 Free Software Foundation, Inc. 5 6 This file is part of GNU Bash, the Bourne Again SHell. 7 8 Bash is free software: you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation, either version 3 of the License, or 11 (at your option) any later version. 12 13 Bash is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with Bash. If not, see <http://www.gnu.org/licenses/>. 20*/ 21 22#include <config.h> 23 24#include "bashtypes.h" 25#include "posixstat.h" 26 27#if defined (HAVE_UNISTD_H) 28# include <unistd.h> 29#endif 30 31#include "bashansi.h" 32 33#include "shell.h" 34#include "findcmd.h" 35#include "hashcmd.h" 36 37extern int hashing_enabled; 38 39HASH_TABLE *hashed_filenames = (HASH_TABLE *)NULL; 40 41static void phash_freedata __P((PTR_T)); 42 43void 44phash_create () 45{ 46 if (hashed_filenames == 0) 47 hashed_filenames = hash_create (FILENAME_HASH_BUCKETS); 48} 49 50static void 51phash_freedata (data) 52 PTR_T data; 53{ 54 free (((PATH_DATA *)data)->path); 55 free (data); 56} 57 58void 59phash_flush () 60{ 61 if (hashed_filenames) 62 hash_flush (hashed_filenames, phash_freedata); 63} 64 65/* Remove FILENAME from the table of hashed commands. */ 66int 67phash_remove (filename) 68 const char *filename; 69{ 70 register BUCKET_CONTENTS *item; 71 72 if (hashing_enabled == 0 || hashed_filenames == 0) 73 return 0; 74 75 item = hash_remove (filename, hashed_filenames, 0); 76 if (item) 77 { 78 if (item->data) 79 phash_freedata (item->data); 80 free (item->key); 81 free (item); 82 return 0; 83 } 84 return 1; 85} 86 87/* Place FILENAME (key) and FULL_PATH (data->path) into the 88 hash table. CHECK_DOT if non-null is for future calls to 89 phash_search (); it means that this file was found 90 in a directory in $PATH that is not an absolute pathname. 91 FOUND is the initial value for times_found. */ 92void 93phash_insert (filename, full_path, check_dot, found) 94 char *filename, *full_path; 95 int check_dot, found; 96{ 97 register BUCKET_CONTENTS *item; 98 99 if (hashing_enabled == 0) 100 return; 101 102 if (hashed_filenames == 0) 103 phash_create (); 104 105 item = hash_insert (filename, hashed_filenames, 0); 106 if (item->data) 107 free (pathdata(item)->path); 108 else 109 { 110 item->key = savestring (filename); 111 item->data = xmalloc (sizeof (PATH_DATA)); 112 } 113 pathdata(item)->path = savestring (full_path); 114 pathdata(item)->flags = 0; 115 if (check_dot) 116 pathdata(item)->flags |= HASH_CHKDOT; 117 if (*full_path != '/') 118 pathdata(item)->flags |= HASH_RELPATH; 119 item->times_found = found; 120} 121 122/* Return the full pathname that FILENAME hashes to. If FILENAME 123 is hashed, but (data->flags & HASH_CHKDOT) is non-zero, check 124 ./FILENAME and return that if it is executable. This always 125 returns a newly-allocated string; the caller is responsible 126 for freeing it. */ 127char * 128phash_search (filename) 129 const char *filename; 130{ 131 register BUCKET_CONTENTS *item; 132 char *path, *dotted_filename, *tail; 133 int same; 134 135 if (hashing_enabled == 0 || hashed_filenames == 0) 136 return ((char *)NULL); 137 138 item = hash_search (filename, hashed_filenames, 0); 139 140 if (item == NULL) 141 return ((char *)NULL); 142 143 /* If this filename is hashed, but `.' comes before it in the path, 144 see if ./filename is executable. If the hashed value is not an 145 absolute pathname, see if ./`hashed-value' exists. */ 146 path = pathdata(item)->path; 147 if (pathdata(item)->flags & (HASH_CHKDOT|HASH_RELPATH)) 148 { 149 tail = (pathdata(item)->flags & HASH_RELPATH) ? path : (char *)filename; /* XXX - fix const later */ 150 /* If the pathname does not start with a `./', add a `./' to it. */ 151 if (tail[0] != '.' || tail[1] != '/') 152 { 153 dotted_filename = (char *)xmalloc (3 + strlen (tail)); 154 dotted_filename[0] = '.'; dotted_filename[1] = '/'; 155 strcpy (dotted_filename + 2, tail); 156 } 157 else 158 dotted_filename = savestring (tail); 159 160 if (executable_file (dotted_filename)) 161 return (dotted_filename); 162 163 free (dotted_filename); 164 165#if 0 166 if (pathdata(item)->flags & HASH_RELPATH) 167 return ((char *)NULL); 168#endif 169 170 /* Watch out. If this file was hashed to "./filename", and 171 "./filename" is not executable, then return NULL. */ 172 173 /* Since we already know "./filename" is not executable, what 174 we're really interested in is whether or not the `path' 175 portion of the hashed filename is equivalent to the current 176 directory, but only if it starts with a `.'. (This catches 177 ./. and so on.) same_file () tests general Unix file 178 equivalence -- same device and inode. */ 179 if (*path == '.') 180 { 181 same = 0; 182 tail = (char *)strrchr (path, '/'); 183 184 if (tail) 185 { 186 *tail = '\0'; 187 same = same_file (".", path, (struct stat *)NULL, (struct stat *)NULL); 188 *tail = '/'; 189 } 190 191 return same ? (char *)NULL : savestring (path); 192 } 193 } 194 195 return (savestring (path)); 196} 197