new function isc_file_test() as framework for determining various attributes

of a pathname

lib/isc/include/isc/file.h

@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: file.h,v 1.18 2001/05/08 19:47:54 gson Exp $ */
+/* $Id: file.h,v 1.19 2001/05/31 10:53:13 tale Exp $ */
 
 #ifndef ISC_FILE_H
 #define ISC_FILE_H 1
@@ -25,6 +25,39 @@
 #include <isc/lang.h>
 #include <isc/types.h>
 
+/*
+ * Definitions for the isc_file_test() 'what' argument.
+ *
+ * Notes:
+ *	ISC_FILE_EXISTS tests for existence, but not type.  It can fail
+ *	if the user does not have sufficient permissions to explore the
+ *	full path of the file.
+ *
+ *	ISC_FILE_ABSOLUTE tests for pathnames that start from the root
+ *	of a filesystem hierarchy.
+ *
+ * 	ISC_FILE_CURRENTDIR is an extremely simplistic test.  On Unix systems,
+ *	it only returns true if the pathname is ".".  It will return false
+ *	for "subdir/..", for example.
+ *
+ * Unimplemented, perhaps desirable:
+ *	ISC_FILE_REGULAR
+ *	ISC_FILE_DIRECTORY
+ *	ISC_FILE_SYMLINK
+ *	ISC_FILE_SPECIAL
+ *		ISC_FILE_BLOCK ?
+ *		ISC_FILE_CHARACTER ?
+ *		ISC_FILE_PIPE ?
+ *		ISC_FILE_SOCKET ?
+ * 	ISC_FILE_READABLE
+ *	ISC_FILE_WRITABLE
+ *	ISC_FILE_RUNABLE
+ *	ISC_FILE_EMPTY
+ */
+#define ISC_FILE_EXISTS		0x00000001
+#define ISC_FILE_ABSOLUTE	0x00000002
+#define ISC_FILE_CURRENTDIR	0x00000004
+
 ISC_LANG_BEGINDECLS
 
 isc_result_t
@@ -165,6 +198,26 @@ isc_file_rename(const char *oldname, const char *newname);
  * Rename the file 'oldname' to 'newname'.
  */
 
+isc_boolean_t
+isc_file_test(const char *filename, isc_uint32_t what);
+/*
+ * Test for various file attributes, such as existence or writability.
+ *
+ * Notes:
+ *	This is like the Unix shell test(1) command.
+ *
+ *	If more than one test is specified in 'what' then ALL
+ *	of them must be true for ISC_TRUE to be returned.
+ *	To test instead for traits that can be independently true,
+ *	use multiple calls to isc_file_test().
+ *
+ *	Functionality is being added only as it is needed.  See the list
+ *	at the start of the file for which tests have been implemented.
+ *
+ *	It is intended that this function will supersede both
+ *	isc_file_isabsolute() and isc_file_iscurrentdir().
+ */
+
 isc_boolean_t
 isc_file_isabsolute(const char *filename);
 /*

lib/isc/unix/file.c

@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: file.c,v 1.33 2001/05/08 19:47:55 gson Exp $ */
+/* $Id: file.c,v 1.34 2001/05/31 10:53:14 tale Exp $ */
 
 #include <config.h>
 
@@ -225,6 +225,36 @@ isc_file_rename(const char *oldname, const char *newname) {
 		return (isc__errno2result(errno));
 }
 
+isc_boolean_t
+isc_file_test(const char *pathname, isc_uint32_t what) {
+	isc_boolean_t tf = ISC_TRUE;
+	isc_result_t result;
+	struct stat stats;
+
+	INSIST(what != 0);
+	INSIST((what & ~(ISC_FILE_EXISTS |
+			 ISC_FILE_ABSOLUTE |
+			 ISC_FILE_CURRENTDIR))
+	       == 0);
+
+	if ((what & ISC_FILE_EXISTS) != 0) {
+		/*
+		 * When file type tests are implemented, only one
+		 * file_stats() should be done.
+		 */
+		result = file_stats(pathname, &stats);
+		tf = ISC_TF(tf && result == ISC_R_SUCCESS);
+	}
+
+	if ((what & ISC_FILE_ABSOLUTE) != 0)
+		tf = ISC_TF(tf && pathname[0] == '/');
+
+	if ((what & ISC_FILE_CURRENTDIR) != 0)
+		tf = ISC_TF(tf && pathname[0] == '.' && pathname[1] == '\0');
+
+	return (tf);
+}
+
 isc_boolean_t
 isc_file_isabsolute(const char *filename) {
 	return (ISC_TF(filename[0] == '/'));
@@ -242,6 +272,7 @@ isc_file_basename(const char *filename) {
 	s = strrchr(filename, '/');
 	if (s == NULL)
 		return (filename);
+
 	return (s + 1);
 }
 
@@ -249,8 +280,10 @@ isc_result_t
 isc_file_progname(const char *filename, char *buf, size_t buflen) {
 	const char *base = isc_file_basename(filename);
 	size_t len = strlen(base) + 1;
+
 	if (len > buflen)
 		return (ISC_R_NOSPACE);
 	memcpy(buf, base, len);
+
 	return (ISC_R_SUCCESS);
 }