164. [cleanup] Added functions isc_file_fopen(), isc_file_fclose(),

isc_file_fseek(), isc_file_fread(), isc_file_fwrite(),
                        isc_file_fflush(), isc_file_ffsync(), isc_file_remove()
                        to encapsulate nonportable usage of errno and fflush().

lib/isc/include/isc/file.h

@@ -90,6 +90,7 @@ isc_file_mktemplate(const char *path, char *buf, size_t buflen);
  *				of the path with the internal template string.
  */
 
+
 isc_result_t
 isc_file_openunique(char *templet, FILE **fp);
 /*
@@ -147,6 +148,58 @@ isc_file_openunique(char *templet, FILE **fp);
  *		Something totally unexpected happened.
  */
 
+
+isc_result_t
+isc_file_fopen(const char *filename, const char *mode, FILE **fp);
+
+isc_result_t
+isc_file_fclose(FILE *f);
+
+isc_result_t
+isc_file_fseek(FILE *f, long offset, int whence);
+
+isc_result_t
+isc_file_fread(void *ptr, size_t size, size_t nmemb, FILE *f,
+	       size_t *nret);
+
+isc_result_t
+isc_file_fwrite(const void *ptr, size_t size, size_t nmemb, FILE *f,
+		size_t *nret);
+
+isc_result_t
+isc_file_fflush(FILE *f);
+
+/*
+ * These functions are wrappers around the corresponding
+ * stdio functions, returning a detailed error code in the
+ * form of an an isc_result_t.  ANSI C does not guarantee
+ * that stdio functions set errno, hence these functions 
+ * must use platform dependent methods (e.g., the POSIX errno)
+ * to construct the error code.
+ */
+
+isc_result_t
+isc_file_ffsync(FILE *f);
+/*
+ * Invoke fsync() on the file descriptor underlying
+ * an stdio stream, or an equivalent system-dependent
+ * operation.  Note that this function has no direct
+ * counterpart in the stdio library.
+ */
+
+isc_result_t
+isc_file_remove(const char *filename);
+/*
+ * Remove the file named by 'filename'.
+ */
+
+/*
+ * XXX We should also have a isc_file_writeeopen() function
+ * for safely open a file in a publicly writable directory
+ * (see write_open() in BIND 8's ns_config.c).
+ */
+
+
 ISC_LANG_ENDDECLS
 
 #endif /* ISC_FILE_H */