glibc/hurd/path-lookup.c

123 lines
4.2 KiB
C

/* Filename lookup using a search path
Copyright (C) 1995-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Written by Miles Bader <miles@gnu.ai.mit.edu>
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <string.h>
#include <hurd.h>
#include <hurd/lookup.h>
/* If FILE_NAME contains a '/', or PATH is NULL, call FUN with FILE_NAME, and
return the result (if PREFIXED_NAME is non-NULL, setting *PREFIXED_NAME to
NULL). Otherwise, call FUN repeatedly with FILE_NAME prefixed with each
successive `:' separated element of PATH, returning whenever FUN returns
0 (if PREFIXED_NAME is non-NULL, setting *PREFIXED_NAME to the resulting
prefixed path). If FUN never returns 0, return the first non-ENOENT
return value, or ENOENT if there is none. */
error_t
file_name_path_scan (const char *file_name, const char *path,
error_t (*fun)(const char *name),
char **prefixed_name)
{
if (path == NULL || index (file_name, '/'))
{
if (prefixed_name)
*prefixed_name = 0;
return (*fun)(file_name);
}
else
{
error_t real_err = 0;
size_t file_name_len = strlen (file_name);
for (;;)
{
error_t err;
const char *next = index (path, ':') ?: path + strlen (path);
size_t pfx_len = next - path;
char pfxed_name[pfx_len + 2 + file_name_len + 1];
if (pfx_len == 0)
pfxed_name[pfx_len++] = '.';
else
memcpy (pfxed_name, path, pfx_len);
if (pfxed_name[pfx_len - 1] != '/')
pfxed_name[pfx_len++] = '/';
memcpy (pfxed_name + pfx_len, file_name, file_name_len + 1);
err = (*fun)(pfxed_name);
if (err == 0)
{
if (prefixed_name)
*prefixed_name = strdup (pfxed_name);
return 0;
}
if (!real_err && err != ENOENT)
real_err = err;
if (*next == '\0')
return real_err ?: ENOENT;
else
path = next + 1;
}
}
}
/* Lookup FILE_NAME and return the node opened with FLAGS & MODE in result
(see hurd_file_name_lookup for details), but a simple filename (without
any directory prefixes) will be consecutively prefixed with the pathnames
in the `:' separated list PATH until one succeeds in a successful lookup.
If none succeed, then the first error that wasn't ENOENT is returned, or
ENOENT if no other errors were returned. If PREFIXED_NAME is non-NULL,
then if RESULT is looked up directly, *PREFIXED_NAME is set to NULL, and
if it is looked up using a prefix from PATH, *PREFIXED_NAME is set to
malloced storage containing the prefixed name. */
error_t
hurd_file_name_path_lookup (error_t (*use_init_port)
(int which, error_t (*operate) (mach_port_t)),
file_t (*get_dtable_port) (int fd),
error_t (*lookup)
(file_t dir, char *name, int flags, mode_t mode,
retry_type *do_retry, string_t retry_name,
mach_port_t *result),
const char *file_name, const char *path,
int flags, mode_t mode,
file_t *result, char **prefixed_name)
{
error_t scan_lookup (const char *name)
{
return
__hurd_file_name_lookup (use_init_port, get_dtable_port, lookup,
name, flags, mode, result);
}
return file_name_path_scan (file_name, path, scan_lookup, prefixed_name);
}
file_t
file_name_path_lookup (const char *file_name, const char *path,
int flags, mode_t mode, char **prefixed_name)
{
error_t err;
file_t result;
err = hurd_file_name_path_lookup (&_hurd_ports_use, &__getdport, 0,
file_name, path, flags, mode,
&result, prefixed_name);
return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
}