File: hashcmd.c

package info (click to toggle)
bash 4.4-5
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 36,372 kB
  • sloc: ansic: 103,485; sh: 7,655; yacc: 5,214; makefile: 4,357; perl: 4,227; asm: 48; awk: 23; sed: 16
file content (196 lines) | stat: -rw-r--r-- 5,223 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/* hashcmd.c - functions for managing a hash table mapping command names to
	       full pathnames. */

/* Copyright (C) 1997-2009 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 "findcmd.h"
#include "hashcmd.h"

extern int hashing_enabled;

HASH_TABLE *hashed_filenames = (HASH_TABLE *)NULL;

static void phash_freedata __P((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));
}