netrc:parse handles following conditions correctly by returning

a default netrc-record:
* the specified file does not exist
* the file does exist but does not have the correct permissions
In both cases a warning is printed on (current-error-port)
So, netrc:parse always returns a usable record.
If you want to catch the errors use netrc:try-parse

modules.scm

@@ -533,7 +533,8 @@
           netrc:lookup-password
           netrc:lookup-login
           netrc:parse
-	  netrc:try-parse))
+	  netrc:try-parse
+	  netrc-refuse?))
 
 (define-structure netrc netrc-interface
   (open defrec-package
@@ -542,7 +543,7 @@
         error-package
         ecm-utilities
 	string-lib
-	conditions signals
+	conditions signals handle
 	let-opt
         scheme)
   (files netrc))

netrc.scm

@@ -1,6 +1,6 @@
 ;;; netrc.scm -- parse authentication information contained in ~/.netrc
 ;;
-;; $Id: netrc.scm,v 1.3 2001/12/18 18:08:08 interp Exp $
+;; $Id: netrc.scm,v 1.4 2001/12/27 16:45:32 interp Exp $
 ;;
 ;; Please send suggestions and bug reports to <emarsden@mail.dotcom.fr>
 
@@ -27,7 +27,7 @@
 ;; * The macdef statement (defining macros) is not supported.
 ;; * The settings for one machine must be on a single line.
 ;; * The is no error proof while reading the file.
-;; * default must not be the last line of the netrc-file
+;; * default need not be the last line of the netrc-file
 
 
 
@@ -36,22 +36,61 @@
 ;; (user-mail-address) -> string
 ;;    Calculate the user's email address, as per the Emacs function of
 ;;    the same name. Will take into account the environment variable
-;;    REPLYTO, if set.
+;;    REPLYTO, if set. Otherwise the mail-address will look like
+;;    user@hostname.
 ;;
-;; (netrc:default-login) -> string
+;; (netrc:parse [filename [fallback-password [fallback-login]]]) 
-;;    Return the default login specified by the ~/.netrc file or "anonymous"
+;;  -> netrc-record
+;;    * parses the netrc file and returns a netrc-record, containing all
+;;      necessary information for the following procedures.
+;;    * FILENAME defaults to "~/.netrc"
+;;      FALLBACK-PASSWORD defaults to the result of (user-mail-address)
+;;      FALLBACK-LOGIN defaults to "anonymous"
+;;    * if the netrc file does not provide a default password or a default 
+;;      login (stated by the "default" statement), FALLBACK-PASSWORD and 
+;;      FALLBACK-LOGIN will be used as default password or login, respectively.
+;;      (thus, user-mail-address is only called if the netrc file does not 
+;;      contain a default specification)
+;;    * if the netrc file does not exist, a netrc-record filled with
+;;      default values is returned.
+;;    * if the netrc file does not have the correct permissions, a message is
+;;      printed to current error port and a netrc-record filled with default 
+;;      values is returned.
 ;;
-;; (netrc:default-password) -> string
+;; (netrc:try-parse filename fallback-password fallback-login) -> netrc-record
-;;    Return the default password specified by the ~/.netrc file or
+;;    parses the netrc file and returns a netrc-record, containing all
-;;    to the mail-addres (result of (user-mail-address))
+;;    necessary information for the following procedures.
+;;    if there is no file called FILENAME, the according error will be raised
+;;    if the specified file does not have the correct permissions set,
+;;    a netrc-refuse-warning will be signalled.
+;;    so if you don't like the error handling of netrc:parse, use 
+;;    netrc:try-parse and catch the signalled conditions.
 ;;
-;; (netrc:lookup machine) -> string x string x string
+;; (netrc:lookup netrc-record machine [default?]) -> string x string x string
-;;     Return the login,password,account information for MACHINE
+;;    Return the login,password,account information for MACHINE
-;;     specified by the ~/.netrc file.
+;;    specified by the netrc file.
-;;     If there is no such machine specified, the condition 'netrc:no-such-entry
+;;    If DEFAULT? is #t, default values are returned if no such
-;;     is signalled, that can be caught with with-handler.
+;;    MACHINE is specified in the netrc file. Otherwise, #f,#f,#f
-;;     If you catch this signal, you probably want to use netrc:default-login
+;;    is returned
-;;     and netrc:default-password, that are always set to usable values.
+;;
+;; (netrc:lookup-password netrc-record machine [default?]) -> string
+;;    Return the password information for MACHINE specified by the
+;;    netrc file.
+;;    If DEFAULT? is #t, the default password is returned if no such
+;;    MACHINE is specified. Otherwise, #f is returned.
+;;
+;; (netrc:lookup-login netrc-record machine [default?]) -> string
+;;    Return the login information for MACHINE specified by the
+;;    netrc file.
+;;    If DEFAULT? is #t, the default login is returned if no such
+;;    MACHINE is specified. Otherwise, #f is returned.
+;;
+;; (netrc:default-login netrc-record) -> string
+;;    Return the default login specified by the netrc file or "anonymous"
+;;
+;; (netrc:default-password netrc-record) -> string
+;;    Return the default password specified by the netrc file or
+;;    the mail-addres (result of (user-mail-address))
 
 
 
@@ -61,7 +100,7 @@
 ;;   Netrc.pm
 ;;
 ;; * ange-ftp.el (transparent remote file access for Emacs) parses the
-;;   user's ~/.netrc file
+;;   user's netrc file
 
 
 ;;; Portability ==================================================
@@ -74,9 +113,12 @@
 ;;
 ;; * Remove restrictions (as stated in 'Overview') and behave like
 ;;   /usr/bin/ftp behaves
-;; * perhaps: adding case-insensitivity
+;; * perhaps: adding case-insensitivity (for host names)
 ;; * perhaps: better record-disclosers for netrc-entry- and netrc-records
 
+
+; return the user's mail address, either specified by the environment
+; variable REPLYTO or "user@hostname".
 (define (user-mail-address)
   (or (getenv "REPLYTO")
       (string-append (user-login-name) "@" (system-fqdn))))
@@ -98,11 +140,11 @@
 	  (values (netrc-entry:login record)
 		  (netrc-entry:password record)
 		  (netrc-entry:account record))
-	  (and lookup-default?
+	  (if lookup-default?
-	       (values (netrc:default-login netrc-record)
+	      (values (netrc:default-login netrc-record)
-		       (netrc:default-password netrc-record)
+		      (netrc:default-password netrc-record)
-		       #f)
+		      #f)
-	       (values #f #f #f))))))
+	      (values #f #f #f))))))
   
 ; does the same as netrc:lookup, but returns only the password (or #f)
 (define (netrc:lookup-password netrc-record machine . lookup-default?)
@@ -141,38 +183,70 @@
 ; default-login:      default login name for any not specified machine
 ;                     defaults to "anonymous"
 ;                     default login in netrc-file overwrites this setting
-; (default-login is expected after default-password as users usually want
+; * (default-login is expected after default-password as users usually want
-; to change the default-password (to something else than their mail-address) 
+;   to change the default-password (to something else than their mail-address) 
-; rather than the login-name)(define (netrc:parse . args)
+;   rather than the login-name)(define (netrc:parse . args)
-; if the given file does not exist, than a default netrc-record is returned
+; * if the given file does not exist or it has the wrong permissions, 
-; if you don't want this, use netrc:try-parse; note that you have to
+;   than a default netrc-record is returned
-; resolve the file-name on your own
+; * if you don't want expected errors to be captured, use netrc:try-parse; 
+;   note that you have to resolve the file-name on your own
+(define-condition-type 'netrc-refuse '(warning))
+(define netrc-refuse? (condition-predicate 'netrc-refuse))
+
 (define (netrc:parse . args)
   (let-optionals 
    args ((file-name         "~/.netrc")
 	 (default-password  #f)   ; both ... 
-	 (default-login     #f))  ; ... are set if netrc-file does not provide default-values
+	 (default-login     #f))  ; ... are set if netrc-file does
-   (let ((file-name (resolve-file-name file-name)))
+					; not provide default-values
+   (let* ((file-name (resolve-file-name file-name))
+	  (local-default-login (lambda () "anonymous"))
+	  (local-default-password (lambda () (user-mail-address)))
+	  (local-default-netrc-record 
+	   (lambda ()
+	     (make-netrc '() 
+			 (or default-login (local-default-login)) 
+			 (or default-password (local-default-password)) 
+			 #f))))
+; i know, this double-handler sucks; has anyone a better idea?
      (call-with-current-continuation
       (lambda (exit)
-	(with-errno-handler*
+	(with-handler
-	 (lambda (errno packet)
+	 (lambda (error more)
-	   (if (= errno errno/noent)
+	   (if (netrc-refuse? error)
-	       (exit (make-netrc '() 
+	       (begin
-				 (or default-login "anonymous") 
+		 (format (current-error-port)
-				 (or default-password (user-mail-address)) 
+			 "netrc: Warning: ~a~%"
-				 #f))))
+			 (car (condition-stuff error)))
+		 (exit (local-default-netrc-record)))))
 	 (lambda ()
-	   (let ((netrc-record (netrc:try-parse file-name default-password default-login)))
+	   (with-errno-handler*
-	     (if netrc-record
+	    (lambda (errno packet)
-		 netrc-record
+	      (if (= errno errno/noent)
-		 (begin
+		  (begin
-		   (set-netrc:default-password netrc-record (or default-password (user-mail-address)))
+		    (format (current-error-port)
-		   (set-netrc:default-login netrc-record (or default-login "anonymous"))
+			    "netrc: Warning: no such file or directory: ~a~%"
-		   netrc-record))))))))))
+			    file-name)
+		    (exit (local-default-netrc-record)))))
+	    (lambda ()
+	      (let ((netrc-record 
+		     (netrc:try-parse file-name default-password default-login)))
+		(if netrc-record
+		    netrc-record
+		    (begin
+		      (set-netrc:default-password 
+		       netrc-record 
+		       (or default-password (local-default-password)))
+		      (set-netrc:default-login 
+		       netrc-record 
+		       (or default-login (local-default-login)))
+		      netrc-record))))))))))))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; nothing exported below
+;; except
+;;  netrc:default-password
+;;  netrc:default-login
 
 (define-record netrc-entry
   machine
@@ -209,7 +283,10 @@
 (define (netrc:check-permissions file-name)
   (let ((perms (- (file-mode file-name) 32768)))
     (if (positive? (bitwise-and #b000111111 perms))
-	(error "Not parsing ~/.netrc file; dangerous permissions."))))
+	(signal 'netrc-refuse 
+		(format #f 
+			"Not parsing ~s (netrc file); dangerous permissions." 
+			file-name)))))
 
 ; tries to match target on line and returns the first group,
 ; or #f if there is no match