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-rw-r--r--hurd/path-lookup.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/hurd/path-lookup.c b/hurd/path-lookup.c
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+/* Filename lookup using a search path
+
+   Copyright (C) 1995, 1996 Free Software Foundation, Inc.
+
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   This program 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 2, or (at
+   your option) any later version.
+
+   This program 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 this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#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
+	    bcopy (path, pfxed_name, pfx_len);
+	  if (pfxed_name[pfx_len - 1] != '/')
+	    pfxed_name[pfx_len++] = '/';
+	  bcopy (file_name, pfxed_name + pfx_len, 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 consectutively 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),
+			    const char *file_name, const char *path,
+			    int flags, mode_t mode,
+			    file_t *result, char **prefixed_name)
+{
+  error_t lookup (const char *name)
+    {
+      return
+	__hurd_file_name_lookup (use_init_port, get_dtable_port,
+				 name, flags, mode, result);
+    }
+  return file_name_path_scan (file_name, path, 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,
+				    file_name, path, flags, mode,
+				    &result, prefixed_name);
+
+  return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
+}