diff options
| -rw-r--r-- | scm/mcron/main.scm | 252 |
1 files changed, 115 insertions, 137 deletions
diff --git a/scm/mcron/main.scm b/scm/mcron/main.scm index 946ab7c..a964795 100644 --- a/scm/mcron/main.scm +++ b/scm/mcron/main.scm @@ -39,11 +39,6 @@ (srfi srfi-2) (srfi srfi-26)) -;; Turn debugging on if indicated. -(when config-debug - (debug-enable 'debug) - (debug-enable 'backtrace)) - (define* (command-name #:optional (command (car (command-line)))) "Extract the actual command name from COMMAND. This returns the last part of COMMAND without any non-alphabetic characters. For example \"in.cron\" and @@ -125,9 +120,6 @@ There is NO WARRANTY, to the extent permitted by law.\n" command name version short-name) (quit))) -(when (option-ref options 'version #f) - (show-version)) - (define (show-package-information) "Display where to get help and send bug reports." (simple-format #t "\nReport bugs to: ~a.\n @@ -177,9 +169,6 @@ reading all the information in the users' crontabs and in /etc/crontab.\n (show-package-information) (quit)) -(when (option-ref options 'help #f) - (show-help)) - (define (delete-run-file) "Remove the /var/run/cron.pid file so that crontab and other invocations of cron don't get the wrong idea that a daemon is currently running. This @@ -190,53 +179,12 @@ received." noop) (quit)) - - -;; Setup the cron process, if appropriate. If there is already a -;; /var/run/cron.pid file, then we must assume a cron daemon is already running -;; and refuse to start another one. -;; -;; Otherwise, clear the MAILTO environment variable so that output from cron -;; jobs is sent to the various users (this may still be overridden in the -;; configuration files), and call the function in the C wrapper to set up -;; terminal signal responses to vector to the procedure above. The PID file will -;; be filled in properly later when we have forked our daemon process (but not -;; done if we are only viewing the schedules). - -(when (eq? command-type 'cron) - (unless (eqv? (getuid) 0) - (mcron-error 16 - "This program must be run by the root user (and should " - "have been installed as such).")) - (when (access? config-pid-file F_OK) - (mcron-error 1 - "A cron daemon is already running.\n" - " (If you are sure this is not true, remove the file\n" - " " - config-pid-file - ".)")) - (unless (option-ref options 'schedule #f) - (with-output-to-file config-pid-file noop)) - (setenv "MAILTO" #f) - (c-set-cron-signals)) - (define (stdin->string) "Return standard input as a string." (with-output-to-string (lambda () (do ((in (read-char) (read-char))) ((eof-object? in)) (display in))))) - - -;; Now we have the procedures in place for dealing with the contents of -;; configuration files, the crontab personality is able to validate such -;; files. If the user requested the crontab personality, we load and run the -;; code here and then get out. - -(when (eq? command-type 'crontab) - (load "crontab.scm") - (quit)) - (define (regular-file? file) "Return true if FILE is a regular file." (catch 'system-error @@ -321,67 +269,6 @@ operation. The permissions on the /var/cron/tabs directory enforce this." 4 "You do not have permission to access the system crontabs.")))) - - -;; Having defined all the necessary procedures for scanning various sets of -;; files, we perform the actual configuration of the program depending on the -;; personality we are running as. If it is mcron, we either scan the files -;; passed on the command line, or else all the ones in the user's .config/cron -;; (or .cron) directory. If we are running under the cron personality, we read -;; the /var/cron/tabs directory and also the /etc/crontab file. - -(case command-type - ((mcron) (if (null? (option-ref options '() '())) - (process-files-in-user-directory) - (for-each (lambda (file-path) - (process-user-file file-path #t)) - (option-ref options '() '())))) - - ((cron) (process-files-in-system-directory) - (use-system-job-list) - (catch-mcron-error - (read-vixie-file "/etc/crontab" parse-system-vixie-line)) - (use-user-job-list) - (unless (option-ref options 'noetc #f) - (display "WARNING: -cron will check for updates to /etc/crontab EVERY MINUTE. If you do\n -not use this file, or you are prepared to manually restart cron whenever you\n -make a change, then it is HIGHLY RECOMMENDED that you use the --noetc\n -option.\n") - (set-configuration-user "root") - (job '(- (next-minute-from (next-minute)) 6) - check-system-crontab - "/etc/crontab update checker.")))) - - - -;; If the user has requested a schedule of jobs that will run, we provide the -;; information here and then get out. -;; -;; Start by determining the number of time points in the future that output is -;; required for. This may be provided on the command line as a parameter to the -;; --schedule option, or else we assume a default of 8. Finally, ensure that the -;; count is some positive integer. - -(and-let* ((count (option-ref options 'schedule #f))) - (set! count (string->number count)) - (display (get-schedule (if (<= count 0) 1 count))) - (quit)) - - - -;; If we are supposed to run as a daemon process (either a --daemon option has -;; been explicitly used, or we are running as cron or crond), detach from the -;; terminal now. If we are running as cron, we can now write the PID file. - -(when (option-ref options 'daemon (eq? command-type 'cron)) - (unless (eqv? (primitive-fork) 0) - (quit)) - (setsid) - (when (eq? command-type 'cron) - (with-output-to-file config-pid-file - (lambda () (display (getpid)) (newline))))) - (define (cron-file-descriptors) "Establish a socket to listen for updates from a crontab program, and return a list containing the file descriptors correponding to the files read by @@ -422,28 +309,119 @@ comes in on the above socket." (set-configuration-user user) (read-vixie-file (string-append config-spool-dir "/" user-name))))))) + +;;; +;;; Entry point. +;;; + +(define (main . args) + ;; Turn debugging on if indicated. + (when config-debug + (debug-enable 'debug) + (debug-enable 'backtrace)) + (when (option-ref options 'version #f) + (show-version)) + (when (option-ref options 'help #f) + (show-help)) + + ;; Setup the cron process, if appropriate. If there is already a + ;; /var/run/cron.pid file, then we must assume a cron daemon is already + ;; running and refuse to start another one. + ;; + ;; Otherwise, clear the MAILTO environment variable so that output from cron + ;; jobs is sent to the various users (this may still be overridden in the + ;; configuration files), and call the function in the C wrapper to set up + ;; terminal signal responses to vector to the procedure above. The PID file + ;; will be filled in properly later when we have forked our daemon process + ;; (but not done if we are only viewing the schedules). + (when (eq? command-type 'cron) + (unless (eqv? (getuid) 0) + (mcron-error 16 + "This program must be run by the root user (and should " + "have been installed as such).")) + (when (access? config-pid-file F_OK) + (mcron-error 1 + "A cron daemon is already running.\n" + " (If you are sure this is not true, remove the file\n" + " " + config-pid-file + ".)")) + (unless (option-ref options 'schedule #f) + (with-output-to-file config-pid-file noop)) + (setenv "MAILTO" #f) + (c-set-cron-signals)) + + ;; Now we have the procedures in place for dealing with the contents of + ;; configuration files, the crontab personality is able to validate such + ;; files. If the user requested the crontab personality, we load and run the + ;; code here and then get out. + (when (eq? command-type 'crontab) + (load "crontab.scm") + (quit)) - -;; Added by Sergey Poznyakoff. This no-op will collect zombie child processes -;; as soon as they die. This is a big improvement as previously they stayed -;; around the system until the next time mcron wakes to fire a new job off. - -;; Unfortunately it seems to interact badly with the select system call, -;; wreaking havoc... - -;; (sigaction SIGCHLD (lambda (sig) noop) SA_RESTART) - - - -;; Now the main loop. Forever execute the run-job-loop procedure in the mcron -;; core, and when it drops out (can only be because a message has come in on the -;; socket) we process the socket request before restarting the loop again. -;; Sergey Poznyakoff: we can also drop out of run-job-loop because of a SIGCHLD, -;; so must test FDES-LIST. - -(catch-mcron-error - (let ((fdes-list (cron-file-descriptors))) - (while #t - (run-job-loop fdes-list) - (unless (null? fdes-list) - (process-update-request fdes-list))))) + ;; Having defined all the necessary procedures for scanning various sets of + ;; files, we perform the actual configuration of the program depending on + ;; the personality we are running as. If it is mcron, we either scan the + ;; files passed on the command line, or else all the ones in the user's + ;; .config/cron (or .cron) directory. If we are running under the cron + ;; personality, we read the /var/cron/tabs directory and also the + ;; /etc/crontab file. + (case command-type + ((mcron) + (if (null? (option-ref options '() '())) + (process-files-in-user-directory) + (for-each (lambda (file-path) (process-user-file file-path #t)) + (option-ref options '() '())))) + ((cron) + (process-files-in-system-directory) + (use-system-job-list) + (catch-mcron-error (read-vixie-file "/etc/crontab" + parse-system-vixie-line)) + (use-user-job-list) + (unless (option-ref options 'noetc #f) + (display "WARNING: +cron will check for updates to /etc/crontab EVERY MINUTE. If you do\n +not use this file, or you are prepared to manually restart cron whenever you\n +make a change, then it is HIGHLY RECOMMENDED that you use the --noetc\n +option.\n") + (set-configuration-user "root") + (job '(- (next-minute-from (next-minute)) 6) + check-system-crontab + "/etc/crontab update checker.")))) + + ;; If the user has requested a schedule of jobs that will run, we provide + ;; the information here and then get out. Start by determining the number + ;; of time points in the future that output is required for. This may be + ;; provided on the command line as a parameter to the --schedule option, or + ;; else we assume a default of 8. Finally, ensure that the count is some + ;; positive integer. + (and-let* ((count (option-ref options 'schedule #f))) + (set! count (string->number count)) + (display (get-schedule (if (<= count 0) 1 count))) + (quit)) + + ;; If we are supposed to run as a daemon process (either a --daemon option + ;; has been explicitly used, or we are running as cron or crond), detach + ;; from the terminal now. If we are running as cron, we can now write the + ;; PID file. + (when (option-ref options 'daemon (eq? command-type 'cron)) + (unless (eqv? (primitive-fork) 0) + (quit)) + (setsid) + (when (eq? command-type 'cron) + (with-output-to-file config-pid-file + (lambda () (display (getpid)) (newline))))) + + ;; Now the main loop. Forever execute the run-job-loop procedure in the + ;; mcron core, and when it drops out (can only be because a message has come + ;; in on the socket) we process the socket request before restarting the + ;; loop again. Sergey Poznyakoff: we can also drop out of run-job-loop + ;; because of a SIGCHLD, so must test FDES-LIST. + (catch-mcron-error + (let ((fdes-list (cron-file-descriptors))) + (while #t + (run-job-loop fdes-list) + (unless (null? fdes-list) + (process-update-request fdes-list)))))) + +(main) |