diff options
Diffstat (limited to 'redirect.scm')
| -rw-r--r-- | redirect.scm | 189 |
1 files changed, 0 insertions, 189 deletions
diff --git a/redirect.scm b/redirect.scm deleted file mode 100644 index 312b768..0000000 --- a/redirect.scm +++ /dev/null @@ -1,189 +0,0 @@ -;; Copyright (C) 2003 Dale Mellor -;; -;; This file is part of GNU mcron. -;; -;; GNU mcron is free software: you can redistribute it and/or modify it under -;; the terms of the GNU General Public License as published by the Free -;; Software Foundation, either version 3 of the License, or (at your option) -;; any later version. -;; -;; GNU mcron is distributed in the hope that it will be useful, but WITHOUT -;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or -;; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for -;; more details. -;; -;; You should have received a copy of the GNU General Public License along -;; with GNU mcron. If not, see <http://www.gnu.org/licenses/>. - - - -;; This module provides the (with-mail-out action . user) procedure. This -;; procedure runs the action in a child process, allowing the user control over -;; the input and output (including standard error). The input is governed (only -;; in the case of a string action) by the placing of percentage signs in the -;; string; the first delimits the true action from the standard input, and -;; subsequent ones denote newlines to be placed into the input. The output (if -;; there actually is any) is controlled by the MAILTO environment variable. If -;; this is not defined, output is e-mailed to the user passed as argument, if -;; any, or else the owner of the action; if defined but empty then any output is -;; sunk to /dev/null; otherwise output is e-mailed to the address held in the -;; MAILTO variable. - -(define-module (mcron redirect) - #:export (with-mail-out) - #:use-module ((mcron config) :select (config-sendmail)) - #:use-module (mcron vixie-time)) - - - -;; An action string consists of a sequence of characters forming a command -;; executable by the shell, possibly followed by an non-escaped percentage -;; sign. The text after the percentage sign is to be fed to the command's -;; standard input, with further unescaped percents being substituted with -;; newlines. The escape character can itself be escaped. -;; -;; This regexp separates the two halves of the string, and indeed determines if -;; the second part is present. - -(define action-string-regexp (make-regexp "((\\\\%|[^%])*)%(.*)$")) - - - -;; This regexp identifies an escaped percentage sign. - -(define e-percent (make-regexp "\\\\%")) - - -;; Function to execute some action (this may be a shell command, lamdba function -;; or list of scheme procedures) in a forked process, with the input coming from -;; the string, and output (including the error output) being sent to a pipe -;; opened on a mail transport. - -(use-modules (ice-9 popen)) - -(define (with-mail-out action . user) - - ;; Determine the name of the user who is to recieve the mail, looking for a - ;; name in the optional user argument, then in the MAILTO environment - ;; variable, and finally in the LOGNAME environment variable. (The case - ;; MAILTO="" is dealt with specially below.) - - (let* ((mailto (getenv "MAILTO")) - (user (cond (mailto mailto) - ((not (null? user)) (car user)) - (else (getenv "LOGNAME")))) - (parent->child (pipe)) - (child->parent (pipe)) - (child-pid (primitive-fork))) - - - ;; The child process. Close redundant ends of pipes, remap the standard - ;; streams, and run the action, taking care to chop off the input part of an - ;; action string. - - (if (eqv? child-pid 0) - (begin - (close (cdr parent->child)) - (close (car child->parent)) - - (dup2 (port->fdes (car parent->child)) 0) - (close (car parent->child)) - (dup2 (port->fdes (cdr child->parent)) 1) - (close (cdr child->parent)) - (dup2 1 2) - - (cond ((string? action) - (let ((match (regexp-exec action-string-regexp action))) - (system (if match - (let ((action (match:substring match 1))) - (do ((match (regexp-exec e-percent action) - (regexp-exec e-percent action))) - ((not match)) - (set! action (string-append - (match:prefix match) - "%" - (match:suffix match)))) - action) - action)))) - - ((procedure? action) (action)) - ((list? action) (primitive-eval action))) - - (primitive-exit 0))) - - - ;; The parent process. Get rid of redundant pipe ends. - - (close (car parent->child)) - (close (cdr child->parent)) - - - ;; Put stuff to child from after '%' in command line, replacing - ;; other %'s with newlines. Ugly or what? - - (if (string? action) - (let ((port (cdr parent->child)) - (match (regexp-exec action-string-regexp action))) - (if (and match - (match:substring match 3)) - (with-input-from-string (match:substring match 3) - (lambda () - (let loop () - (let ((next-char (read-char))) - (if (not (eof-object? next-char)) - (cond - ((char=? next-char #\%) - (newline port) - (loop)) - ((char=? next-char #\\) - (let ((escape (read-char))) - (if (eof-object? escape) - (display #\\ port) - (if (char=? escape #\%) - (begin - (display #\% port) - (loop)) - (begin - (display #\\ port) - (display escape port) - (loop)))))) - (else - (display next-char port) - (loop))))))))))) - - - ;; So the child process doesn't hang on to its input expecting more stuff. - - (close (cdr parent->child)) - - - ;; That's got streaming into the child's input out of the way, now we stream - ;; the child's output to a mail sink, but only if there is something there - ;; in the first place. - - (if (eof-object? (peek-char (car child->parent))) - - (read-char (car child->parent)) - - (begin - (set-current-output-port (if (and (string? mailto) - (string=? mailto "")) - (open-output-file "/dev/null") - (open-output-pipe - (string-append config-sendmail - " " - user)))) - (set-current-input-port (car child->parent)) - (display "To: ") (display user) (newline) - (display "From: mcron") (newline) - (display (string-append "Subject: " user "@" (gethostname))) - (newline) - (newline) - - (do ((next-char (read-char) (read-char))) - ((eof-object? next-char)) - (display next-char)))) - - (close (car child->parent)) - - (waitpid child-pid))) |