diff options
Diffstat (limited to 'hashcmd.c')
| -rw-r--r-- | hashcmd.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/hashcmd.c b/hashcmd.c new file mode 100644 index 0000000..da3af00 --- /dev/null +++ b/hashcmd.c @@ -0,0 +1,195 @@ +/* hashcmd.c - functions for managing a hash table mapping command names to + full pathnames. */ + +/* Copyright (C) 1997-2020 Free Software Foundation, Inc. + + This file is part of GNU Bash, the Bourne Again SHell. + + Bash 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 3 of the License, or + (at your option) any later version. + + Bash 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 Bash. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include <config.h> + +#include "bashtypes.h" +#include "posixstat.h" + +#if defined (HAVE_UNISTD_H) +# include <unistd.h> +#endif + +#include "bashansi.h" + +#include "shell.h" +#include "flags.h" +#include "findcmd.h" +#include "hashcmd.h" + +HASH_TABLE *hashed_filenames = (HASH_TABLE *)NULL; + +static void phash_freedata PARAMS((PTR_T)); + +void +phash_create () +{ + if (hashed_filenames == 0) + hashed_filenames = hash_create (FILENAME_HASH_BUCKETS); +} + +static void +phash_freedata (data) + PTR_T data; +{ + free (((PATH_DATA *)data)->path); + free (data); +} + +void +phash_flush () +{ + if (hashed_filenames) + hash_flush (hashed_filenames, phash_freedata); +} + +/* Remove FILENAME from the table of hashed commands. */ +int +phash_remove (filename) + const char *filename; +{ + register BUCKET_CONTENTS *item; + + if (hashing_enabled == 0 || hashed_filenames == 0) + return 0; + + item = hash_remove (filename, hashed_filenames, 0); + if (item) + { + if (item->data) + phash_freedata (item->data); + free (item->key); + free (item); + return 0; + } + return 1; +} + +/* Place FILENAME (key) and FULL_PATH (data->path) into the + hash table. CHECK_DOT if non-null is for future calls to + phash_search (); it means that this file was found + in a directory in $PATH that is not an absolute pathname. + FOUND is the initial value for times_found. */ +void +phash_insert (filename, full_path, check_dot, found) + char *filename, *full_path; + int check_dot, found; +{ + register BUCKET_CONTENTS *item; + + if (hashing_enabled == 0) + return; + + if (hashed_filenames == 0) + phash_create (); + + item = hash_insert (filename, hashed_filenames, 0); + if (item->data) + free (pathdata(item)->path); + else + { + item->key = savestring (filename); + item->data = xmalloc (sizeof (PATH_DATA)); + } + pathdata(item)->path = savestring (full_path); + pathdata(item)->flags = 0; + if (check_dot) + pathdata(item)->flags |= HASH_CHKDOT; + if (*full_path != '/') + pathdata(item)->flags |= HASH_RELPATH; + item->times_found = found; +} + +/* Return the full pathname that FILENAME hashes to. If FILENAME + is hashed, but (data->flags & HASH_CHKDOT) is non-zero, check + ./FILENAME and return that if it is executable. This always + returns a newly-allocated string; the caller is responsible + for freeing it. */ +char * +phash_search (filename) + const char *filename; +{ + register BUCKET_CONTENTS *item; + char *path, *dotted_filename, *tail; + int same; + + if (hashing_enabled == 0 || hashed_filenames == 0) + return ((char *)NULL); + + item = hash_search (filename, hashed_filenames, 0); + + if (item == NULL) + return ((char *)NULL); + + /* If this filename is hashed, but `.' comes before it in the path, + see if ./filename is executable. If the hashed value is not an + absolute pathname, see if ./`hashed-value' exists. */ + path = pathdata(item)->path; + if (pathdata(item)->flags & (HASH_CHKDOT|HASH_RELPATH)) + { + tail = (pathdata(item)->flags & HASH_RELPATH) ? path : (char *)filename; /* XXX - fix const later */ + /* If the pathname does not start with a `./', add a `./' to it. */ + if (tail[0] != '.' || tail[1] != '/') + { + dotted_filename = (char *)xmalloc (3 + strlen (tail)); + dotted_filename[0] = '.'; dotted_filename[1] = '/'; + strcpy (dotted_filename + 2, tail); + } + else + dotted_filename = savestring (tail); + + if (executable_file (dotted_filename)) + return (dotted_filename); + + free (dotted_filename); + +#if 0 + if (pathdata(item)->flags & HASH_RELPATH) + return ((char *)NULL); +#endif + + /* Watch out. If this file was hashed to "./filename", and + "./filename" is not executable, then return NULL. */ + + /* Since we already know "./filename" is not executable, what + we're really interested in is whether or not the `path' + portion of the hashed filename is equivalent to the current + directory, but only if it starts with a `.'. (This catches + ./. and so on.) same_file () tests general Unix file + equivalence -- same device and inode. */ + if (*path == '.') + { + same = 0; + tail = (char *)strrchr (path, '/'); + + if (tail) + { + *tail = '\0'; + same = same_file (".", path, (struct stat *)NULL, (struct stat *)NULL); + *tail = '/'; + } + + return same ? (char *)NULL : savestring (path); + } + } + + return (savestring (path)); +} |