$BUILTIN enable
$FUNCTION enable_builtin
-$SHORT_DOC enable [-n] [name ...]
+$SHORT_DOC enable [-pnds] [-a] [-f filename] [name ...]
Enable and disable builtin shell commands. This allows
you to use a disk command which has the same name as a shell
-builtin. If -n is used, the NAMEs become disabled. Otherwise
+builtin. If -n is used, the NAMEs become disabled; otherwise
NAMEs are enabled. For example, to use the `test' found on your
-path instead of the shell builtin version, you type `enable -n test'.
+path instead of the shell builtin version, type `enable -n test'.
+On systems supporting dynamic loading, the -f option may be used
+to load new builtins from the shared object FILENAME. The -d
+option will delete a builtin previously loaded with -f. If no
+non-option names are given, or the -p option is supplied, a list
+of builtins is printed. The -a option means to print every builtin
+with an indication of whether or not it is enabled. The -s option
+restricts the output to the Posix.2 `special' builtins. The -n
+option displays a list of all disabled builtins.
$END
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+# include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include "../bashansi.h"
#include "../shell.h"
#include "../builtins.h"
+#include "../flags.h"
#include "common.h"
+#include "bashgetopt.h"
+
+#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+static int dyn_load_builtin ();
+#endif
+
+#if defined (HAVE_DLCLOSE)
+static int dyn_unload_builtin ();
+#endif
#define ENABLED 1
#define DISABLED 2
+#define SPECIAL 4
+
+#define AFLAG 0x01
+#define DFLAG 0x02
+#define FFLAG 0x04
+#define NFLAG 0x08
+#define PFLAG 0x10
+#define SFLAG 0x20
static int enable_shell_command ();
static void list_some_builtins ();
/* Enable/disable shell commands present in LIST. If list is not specified,
then print out a list of shell commands showing which are enabled and
which are disabled. */
+int
enable_builtin (list)
WORD_LIST *list;
{
- int result = 0, any_failed = 0;
- int disable_p, all_p;
+ int result, flags;
+ int opt, filter;
+#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+ char *filename;
+#endif
- disable_p = all_p = 0;
+ result = EXECUTION_SUCCESS;
+ flags = 0;
- while (list && list->word->word && list->word->word[0] == '-')
+ reset_internal_getopt ();
+ while ((opt = internal_getopt (list, "adnpsf:")) != -1)
{
- char *arg = list->word->word;
-
- list = list->next;
-
- if (ISOPTION (arg, 'n'))
- disable_p = 1;
- else if (arg[1] == 'a' && (arg[2] == 0 || strcmp (arg + 2, "ll") == 0))
- all_p = 1;
- else if (ISOPTION (arg, '-'))
- break;
- else
+ switch (opt)
{
- bad_option (arg);
- return (EXECUTION_FAILURE);
+ case 'a':
+ flags |= AFLAG;
+ break;
+ case 'n':
+ flags |= NFLAG;
+ break;
+ case 'p':
+ flags |= PFLAG;
+ break;
+ case 's':
+ flags |= SFLAG;
+ break;
+ case 'f':
+#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+ flags |= FFLAG;
+ filename = list_optarg;
+ break;
+#else
+ builtin_error ("dynamic loading not available");
+ return (EX_USAGE);
+#endif
+#if defined (HAVE_DLCLOSE)
+ case 'd':
+ flags |= DFLAG;
+ break;
+#else
+ builtin_error ("dynamic loading not available");
+ return (EX_USAGE);
+#endif /* HAVE_DLCLOSE */
+ default:
+ builtin_usage ();
+ return (EX_USAGE);
}
}
- if (!list)
+ list = loptend;
+
+#if defined (RESTRICTED_SHELL)
+ /* Restricted shells cannot load new builtins. */
+ if (restricted && (flags & (FFLAG|DFLAG)))
{
- int filter;
+ builtin_error ("restricted");
+ return (EXECUTION_FAILURE);
+ }
+#endif
- if (all_p)
- filter = ENABLED | DISABLED;
- else if (disable_p)
- filter = DISABLED;
- else
- filter = ENABLED;
+ if (list == 0 || (flags & PFLAG))
+ {
+ filter = (flags & AFLAG) ? (ENABLED | DISABLED)
+ : (flags & NFLAG) ? DISABLED : ENABLED;
+
+ if (flags & SFLAG)
+ filter |= SPECIAL;
list_some_builtins (filter);
}
+#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+ else if (flags & FFLAG)
+ {
+ filter = (flags & NFLAG) ? DISABLED : ENABLED;
+ if (flags & SFLAG)
+ filter |= SPECIAL;
+
+ result = dyn_load_builtin (list, filter, filename);
+ }
+#endif
+#if defined (HAVE_DLCLOSE)
+ else if (flags & DFLAG)
+ {
+ while (list)
+ {
+ opt = dyn_unload_builtin (list->word->word);
+ if (opt == EXECUTION_FAILURE)
+ result = EXECUTION_FAILURE;
+ list = list->next;
+ }
+ }
+#endif
else
{
while (list)
{
- result = enable_shell_command (list->word->word, disable_p);
+ opt = enable_shell_command (list->word->word, flags & NFLAG);
- if (!result)
+ if (opt == EXECUTION_FAILURE)
{
builtin_error ("%s: not a shell builtin", list->word->word);
- any_failed++;
+ result = EXECUTION_FAILURE;
}
list = list->next;
}
}
- return (any_failed ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
+ return (result);
}
/* List some builtins.
for (i = 0; i < num_shell_builtins; i++)
{
- if (!shell_builtins[i].function)
+ if (shell_builtins[i].function == 0 || (shell_builtins[i].flags & BUILTIN_DELETED))
continue;
- if ((filter & ENABLED) &&
- (shell_builtins[i].flags & BUILTIN_ENABLED))
- {
- printf ("enable %s\n", shell_builtins[i].name);
- }
+ if ((filter & SPECIAL) &&
+ (shell_builtins[i].flags & SPECIAL_BUILTIN) == 0)
+ continue;
+
+ if ((filter & ENABLED) && (shell_builtins[i].flags & BUILTIN_ENABLED))
+ printf ("enable %s\n", shell_builtins[i].name);
else if ((filter & DISABLED) &&
((shell_builtins[i].flags & BUILTIN_ENABLED) == 0))
- {
- printf ("enable -n %s\n", shell_builtins[i].name);
- }
+ printf ("enable -n %s\n", shell_builtins[i].name);
}
}
char *name;
int disable_p;
{
- register int i;
- int found = 0;
+ struct builtin *b;
- for (i = 0; i < num_shell_builtins; i++)
+ b = builtin_address_internal (name, 1);
+ if (b == 0)
+ return (EXECUTION_FAILURE);
+
+ if (disable_p)
+ b->flags &= ~BUILTIN_ENABLED;
+ else
+ b->flags |= BUILTIN_ENABLED;
+
+ return (EXECUTION_SUCCESS);
+}
+
+#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+#include <dlfcn.h>
+
+static int
+dyn_load_builtin (list, flags, filename)
+ WORD_LIST *list;
+ int flags;
+ char *filename;
+{
+ WORD_LIST *l;
+ void *handle;
+
+ int total, size, new, replaced;
+ char *struct_name, *name;
+ struct builtin **new_builtins, *b, *new_shell_builtins, *old_builtin;
+
+ if (list == 0)
+ return (EXECUTION_FAILURE);
+
+#ifndef RTLD_LAZY
+#define RTLD_LAZY 1
+#endif
+
+#if defined (_AIX)
+ handle = dlopen (filename, RTLD_NOW|RTLD_GLOBAL);
+#else
+ handle = dlopen (filename, RTLD_LAZY);
+#endif /* !_AIX */
+
+ if (handle == 0)
{
- if (!shell_builtins[i].function)
- continue;
+ builtin_error ("cannot open shared object %s: %s", filename, dlerror ());
+ return (EXECUTION_FAILURE);
+ }
- if (STREQ (name, shell_builtins[i].name))
- {
- found++;
+ for (new = 0, l = list; l; l = l->next, new++)
+ ;
+ new_builtins = (struct builtin **)xmalloc (new * sizeof (struct builtin *));
- if (disable_p)
- shell_builtins[i].flags &= ~BUILTIN_ENABLED;
- else
- shell_builtins[i].flags |= BUILTIN_ENABLED;
+ /* For each new builtin in the shared object, find it and its describing
+ structure. If this is overwriting an existing builtin, do so, otherwise
+ save the loaded struct for creating the new list of builtins. */
+ for (replaced = new = 0; list; list = list->next)
+ {
+ name = list->word->word;
+
+ size = strlen (name);
+ struct_name = xmalloc (size + 8);
+ strcpy (struct_name, name);
+ strcpy (struct_name + size, "_struct");
+
+ b = (struct builtin *)dlsym (handle, struct_name);
+ if (b == 0)
+ {
+ builtin_error ("cannot find %s in shared object %s: %s", struct_name,
+ filename, dlerror ());
+ free (struct_name);
+ continue;
}
+
+ free (struct_name);
+
+ b->flags &= ~STATIC_BUILTIN;
+ if (flags & SPECIAL)
+ b->flags |= SPECIAL_BUILTIN;
+ b->handle = handle;
+
+ if (old_builtin = builtin_address_internal (name, 1))
+ {
+ replaced++;
+ FASTCOPY ((char *)b, (char *)old_builtin, sizeof (struct builtin));
+ }
+ else
+ new_builtins[new++] = b;
+ }
+
+ if (replaced == 0 && new == 0)
+ {
+ free (new_builtins);
+ dlclose (handle);
+ return (EXECUTION_FAILURE);
}
- return (found);
+
+ if (new)
+ {
+ total = num_shell_builtins + new;
+ size = (total + 1) * sizeof (struct builtin);
+
+ new_shell_builtins = (struct builtin *)xmalloc (size);
+ FASTCOPY ((char *)shell_builtins, (char *)new_shell_builtins,
+ num_shell_builtins * sizeof (struct builtin));
+ for (replaced = 0; replaced < new; replaced++)
+ FASTCOPY ((char *)new_builtins[replaced],
+ (char *)&new_shell_builtins[num_shell_builtins + replaced],
+ sizeof (struct builtin));
+
+ new_shell_builtins[total].name = (char *)0;
+ new_shell_builtins[total].function = (Function *)0;
+ new_shell_builtins[total].flags = 0;
+
+ if (shell_builtins != static_shell_builtins)
+ free (shell_builtins);
+
+ shell_builtins = new_shell_builtins;
+ num_shell_builtins = total;
+ initialize_shell_builtins ();
+ }
+
+ free (new_builtins);
+ return (EXECUTION_SUCCESS);
+}
+#endif
+
+#if defined (HAVE_DLCLOSE)
+static void
+delete_builtin (b)
+ struct builtin *b;
+{
+ int ind, size;
+ struct builtin *new_shell_builtins;
+
+ /* XXX - funky pointer arithmetic - XXX */
+ ind = ((int)b - (int)shell_builtins) / sizeof (struct builtin);
+ size = num_shell_builtins * sizeof (struct builtin);
+ new_shell_builtins = (struct builtin *)xmalloc (size);
+
+ /* Copy shell_builtins[0]...shell_builtins[ind - 1] to new_shell_builtins */
+ if (ind)
+ FASTCOPY ((char *)shell_builtins, (char *)new_shell_builtins,
+ ind * sizeof (struct builtin));
+ /* Copy shell_builtins[ind+1]...shell_builtins[num_shell_builtins to
+ new_shell_builtins, starting at ind. */
+ FASTCOPY ((char *)(&shell_builtins[ind+1]),
+ (char *)(&new_shell_builtins[ind]),
+ (num_shell_builtins - ind) * sizeof (struct builtin));
+
+ if (shell_builtins != static_shell_builtins)
+ free (shell_builtins);
+
+ /* The result is still sorted. */
+ num_shell_builtins--;
+ shell_builtins = new_shell_builtins;
+}
+
+static int
+dyn_unload_builtin (name)
+ char *name;
+{
+ struct builtin *b;
+ void *handle;
+ int ref, i;
+
+ b = builtin_address_internal (name, 1);
+ if (b == 0)
+ {
+ builtin_error ("%s: not a shell builtin", name);
+ return (EXECUTION_FAILURE);
+ }
+ if (b->flags & STATIC_BUILTIN)
+ {
+ builtin_error ("%s: not dynamically loaded", name);
+ return (EXECUTION_FAILURE);
+ }
+
+ handle = (void *)b->handle;
+ for (ref = i = 0; i < num_shell_builtins; i++)
+ {
+ if (shell_builtins[i].handle == b->handle)
+ ref++;
+ }
+
+ /* Don't remove the shared object unless the reference count of builtins
+ using it drops to zero. */
+ if (ref == 1 && dlclose (handle) != 0)
+ {
+ builtin_error ("cannot delete %s: %s", name, dlerror ());
+ return (EXECUTION_FAILURE);
+ }
+
+ /* Now remove this entry from the builtin table and reinitialize. */
+ delete_builtin (b);
+
+ return (EXECUTION_SUCCESS);
}
+#endif
projects / platform / upstream / bash.git / blobdiff