or $ gosh -E '(use file.util)(exit (if (< 600 (- (sys-time) (file-ctime "/tmp/foo"))) 1 0))'

ctimelag.scm

#!/usr/bin/env gosh

(use gauche.parseopt)
(use file.util)

(define (main args)
    (let-args (cdr args)
              ((help "h|help" => usage)
               (quiet "q|quiet" #f)
               (lag "l|lag=n" 600)
               (else (opt . _) (usage "Unknown option : " opt)) . rest)
              (when (null? rest) (usage "wrong number of arguments. required 1, got 0."))
              (if (too-much-lag? lag quiet (car rest)) 1 0)))

(define (print-err . messages)
  (let1 err (current-error-port)
        (for-each (^[message] (display message err))
                  messages)
        (newline err)))

(define (usage . messages)
  (let1 msg "usage: ctimelag [opt] <path>
  l|lag=n   => time lag in second, default:600 sec
  q|quiet   => quiet mode
  h|help    => print this usage"
        (if (not (null? messages)) (apply print-err messages))
        (print-err msg)
        (exit 1)))

(define (too-much-lag? lag quiet path)
  (let ((ctime (file-ctime path))
        (sys-time (sys-time)))
    (if (eq? ctime #f) (error "file not found: " path)
        (let1 lag? (< lag (- sys-time ctime))
              (if (not quiet)
                  (begin
                    (print 'path: path)
                    (print 'ctime: ctime)
                    (print 'sys-time: sys-time)
                    (print 'too-much-lag?: lag?)))
              lag?))))