;;; -*- hen -*-
;;; $Revision: 1.5 $
;;;
;;; Tools to make unix programmers happy.

(require-extension srfi-1)

(define-macro (dirname filename)
  `(pathname-directory ,filename))

(define-macro (basename filename)
  (let ((fn filename))       ; avoid multiple evaluations of filename
    `(let ((extension (pathname-extension ,fn)))
       (if extension
           (format "~a.~a" (pathname-file ,fn) extension)
           (pathname-file ,fn)))))

;;; Remove dot files from a directory list: (undotfile (directory "."))
(define (undotfile files)
  (define (dotfile? f)
    (char=? #\. (string-ref f 0)))
  (remove dotfile? files))

;;; Reads passwords in from an open input port and performing some task
;;; on each entry.
(define (passwd-map op port)
  (let loop ((entry (read-line port)))
    (unless (eof-object? entry)
      (op (string-split entry ":" #t))  ; #t - keep empty fields
      (loop (read-line port)))))

;;; same behavior, just fewer entries
(define group-map passwd-map)

;(define (test-passwd-map)
;  (let ((pwd (open-input-file "/etc/passwd")))
;    (passwd-map
;      (lambda (e)
;        (print (length e) " " e))
;      pwd)
;    (close-input-port pwd)))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; yank apart grent and pwent structs: user-information
(define getpwent user-information)
(define pw-name first)
(define pw-passwd second)
(define pw-uid third)
(define pw-gid fourth)
(define pw-gecos fifth)
(define pw-dir sixth)
(define pw-shell seventh)

;;; Something a bit more like user-information's output
(define (getgrent gr)
  (let ((grent (receive (group-information gr))))
    (if (car grent)   ; (#f) returned if named group does not exist
        grent
        (error "no such group" gr))))

(define gr-name first)
(define gr-passwd second)
(define gr-gid third)
(define gr-mem fourth)