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Diffstat (limited to 'main.scm')
| -rw-r--r-- | main.scm | 503 |
1 files changed, 0 insertions, 503 deletions
diff --git a/main.scm b/main.scm deleted file mode 100644 index 36adef9..0000000 --- a/main.scm +++ /dev/null @@ -1,503 +0,0 @@ -;; Copyright (C) 2003, 2012 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 is the 'main' routine for the whole system; the top of this file is the -;; global entry point (after the minimal C wrapper, mcron.c.template); to all -;; intents and purposes the program is pure Guile and starts here. -;; -;; This file is built into mcron.c.template by the makefile, which stringifies -;; the whole lot, and escapes quotation marks and escape characters -;; accordingly. Bear this in mind when considering literal multi-line strings. -;; -;; (l0ad "crontab.scm") (sic) is inlined by the makefile. All other -;; functionality comes through modules in .../share/guile/site/mcron/*.scm. - - - -;; Pull in some constants set by the builder (via autoconf) at configuration -;; time. Turn debugging on if indicated. - -(use-modules (mcron config)) -(if config-debug (begin (debug-enable 'debug) - (debug-enable 'backtrace))) - - - -;; To determine the name of the program, scan the first item of the command line -;; backwards for the first non-alphabetic character. This allows names like -;; in.cron to be accepted as an invocation of the cron command. - -(use-modules (ice-9 regex) (ice-9 rdelim)) - -(define command-name (match:substring (regexp-exec (make-regexp "[[:alpha:]]*$") - (car (command-line))))) - - - -;; Code contributed by Sergey Poznyakoff. Print an error message (made up from -;; the parts of rest), and if the error is fatal (present and non-zero) then -;; exit to the system with this code. - -(define (mcron-error exit-code . rest) - (with-output-to-port (current-error-port) - (lambda () - (for-each display (append (list command-name ": ") rest)) - (newline))) - (if (and exit-code (not (eq? exit-code 0))) - (primitive-exit exit-code))) - - - -;; Code contributed by Sergey Poznyakoff. Execute body. If an 'mcron-error -;; exception occurs, print its diagnostics and exit with its error code. - -(defmacro catch-mcron-error (. body) - `(catch 'mcron-error - (lambda () - ,@body) - (lambda (key exit-code . msg) - (apply mcron-error exit-code msg)))) - - - -;; We will be doing a lot of testing of the command name, so it makes sense to -;; perform the string comparisons once and for all here. - -(define command-type (cond ((string=? command-name "mcron") 'mcron) - ((or (string=? command-name "cron") - (string=? command-name "crond")) 'cron) - ((string=? command-name "crontab") 'crontab) - (else - (mcron-error 12 "The command name is invalid.")))) - - - -;; There are a different set of options for the crontab personality compared to -;; all the others, with the --help and --version options common to all the -;; personalities. - -(use-modules (ice-9 getopt-long)) - -(define options - (catch - 'misc-error - (lambda () - (getopt-long (command-line) - (append - (case command-type - ((crontab) - '((user (single-char #\u) (value #t)) - (edit (single-char #\e) (value #f)) - (list (single-char #\l) (value #f)) - (remove (single-char #\r) (value #f)))) - (else `((schedule (single-char #\s) (value #t) - (predicate - ,(lambda (value) - (string->number value)))) - (daemon (single-char #\d) (value #f)) - (noetc (single-char #\n) (value #f)) - (stdin (single-char #\i) (value #t) - (predicate - ,(lambda (value) - (or (string=? "vixie" value) - (string=? "guile" value)))))))) - '((version (single-char #\v) (value #f)) - (help (single-char #\h) (value #f)))))) - (lambda (key func fmt args . rest) - (mcron-error 1 (apply format (append (list #f fmt) args)))))) - -;; If the user asked for the version of this program, give it to him and get -;; out. - -(if (option-ref options 'version #f) - (begin - (display (string-append "\n -" command-name " (" config-package-string ")\n -Written by Dale Mellor\n -\n -Copyright (C) 2003, 2006, 2014 Dale Mellor\n -This is free software; see the source for copying conditions. There is NO\n -warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n -")) - (quit))) - - - -;; Likewise if the user requested the help text. - -(if (option-ref options 'help #f) - (begin - (display (string-append " -Usage: " (car (command-line)) -(case command-type - - ((mcron) -" [OPTIONS] [FILES]\n -Run an mcron process according to the specifications in the FILES (`-' for\n -standard input), or use all the files in ~/.config/cron (or the \n -deprecated ~/.cron) with .guile or .vixie extensions.\n -\n - -v, --version Display version\n - -h, --help Display this help message\n - -sN, --schedule[=]N Display the next N jobs that will be run by mcron\n - -d, --daemon Immediately detach the program from the terminal\n - and run as a daemon process\n - -i, --stdin=(guile|vixie) Format of data passed as standard input or\n - file arguments (default guile)") - - ((cron) -" [OPTIONS]\n -Unless an option is specified, run a cron daemon as a detached process, \n -reading all the information in the users' crontabs and in /etc/crontab.\n -\n - -v, --version Display version\n - -h, --help Display this help message\n - -sN, --schedule[=]N Display the next N jobs that will be run by cron\n - -n, --noetc Do not check /etc/crontab for updates (HIGHLY\n - RECOMMENDED).") - - ((crontab) - (string-append " [-u user] file\n" - " " (car (command-line)) " [-u user] { -e | -l | -r }\n" - " (default operation is replace, per 1003.2)\n" - " -e (edit user's crontab)\n" - " -l (list user's crontab)\n" - " -r (delete user's crontab)\n")) - - (else "rubbish")) - -"\n\n -Report bugs to " config-package-bugreport ".\n -")) - (quit))) - - - -;; This is called from the C front-end whenever a terminal signal is -;; received. We 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. - -(define (delete-run-file) - (catch #t (lambda () (delete-file config-pid-file) - (delete-file config-socket-file)) - 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). - -(if (eq? command-type 'cron) - (begin - (if (not (eqv? (getuid) 0)) - (mcron-error 16 - "This program must be run by the root user (and should " - "have been installed as such).")) - (if (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 - ".)")) - (if (not (option-ref options 'schedule #f)) - (with-output-to-file config-pid-file noop)) - (setenv "MAILTO" #f) - (c-set-cron-signals))) - - - -;; Define the functions available to the configuration files. While we're here, -;; we'll get the core loaded as well. - -(use-modules (mcron core) - (mcron job-specifier) - (mcron vixie-specification)) - - - -;; Procedure to slurp the standard input into a string. - -(define (stdin->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. - -(if (eq? command-type 'crontab) - (begin - (load "crontab.scm") - (quit))) - - - -;; Code contributed by Sergey Poznyakoff. Determine if the given file is a -;; regular file or not. - -(define (regular-file? file) - (catch 'system-error - (lambda () - (eq? (stat:type (stat file)) 'regular)) - (lambda (key call fmt args . rest) - (mcron-error 0 (apply format (append (list #f fmt) args))) - #f))) - - - -;; Procedure which processes any configuration file according to the -;; extension. If a file is not recognized, it is silently ignored (this deals -;; properly with most editors' backup files, for instance). - -(define guile-file-regexp (make-regexp "\\.gui(le)?$")) -(define vixie-file-regexp (make-regexp "\\.vix(ie)?$")) - -(define (process-user-file file-path . assume-guile) - (cond ((string=? file-path "-") - (if (string=? (option-ref options 'stdin "guile") "vixie") - (read-vixie-port (current-input-port)) - (eval-string (stdin->string)))) - ((or (not (null? assume-guile)) - (regexp-exec guile-file-regexp file-path)) - (load file-path)) - ((regexp-exec vixie-file-regexp file-path) - (read-vixie-file file-path)))) - - - -;; Procedure to run through all the files in a user's ~/.cron and/or -;; $XDG_CONFIG_HOME/cron or ~/.config/cron directories (only happens under the -;; mcron personality). - -(define (process-files-in-user-directory) - (let ((errors 0) - (home-directory (passwd:dir (getpw (getuid))))) - (map (lambda (config-directory) - (catch #t - (lambda () - (let ((directory (opendir config-directory))) - (do ((file-name (readdir directory) (readdir directory))) - ((eof-object? file-name) (closedir directory)) - (process-user-file (string-append config-directory - "/" - file-name))))) - (lambda (key . args) - (set! errors (1+ errors))))) - (list (string-append home-directory "/.cron") - (string-append (or (getenv "XDG_CONFIG_HOME") - (string-append home-directory "/.config")) - "/cron"))) - (if (eq? 2 errors) - (mcron-error 13 - "Cannot read files in your ~/.config/cron (or ~/.cron) " - "directory.")))) - - - -;; Procedure to check that a user name is in the passwd database (it may happen -;; that a user is removed after creating a crontab). If the user name is valid, -;; the full passwd entry for that user is returned to the caller. - -(define (valid-user user-name) - (setpwent) - (do ((entry (getpw) (getpw))) - ((or (not entry) - (string=? (passwd:name entry) user-name)) - (endpwent) - entry))) - - - -;; Procedure to process all the files in the crontab directory, making sure that -;; each file is for a legitimate user and setting the configuration-user to that -;; user. In this way, when the job procedure is run on behalf of the -;; configuration files, the jobs are registered with the system with the -;; appropriate user. Note that only the root user should be able to perform this -;; operation, but we leave it to the permissions on the /var/cron/tabs directory -;; to enforce this. - -(use-modules (srfi srfi-2)) ;; For and-let*. - -(define (process-files-in-system-directory) - (catch #t - (lambda () - (let ((directory (opendir config-spool-dir))) - (do ((file-name (readdir directory) (readdir directory))) - ((eof-object? file-name)) - (and-let* ((user (valid-user file-name))) - (set-configuration-user user) ;; / ?? !!!! - (catch-mcron-error - (read-vixie-file (string-append config-spool-dir - "/" - file-name))))))) - (lambda (key . args) - (mcron-error - 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) - (if (not (option-ref options 'noetc #f)) - (begin - (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. - -(if (option-ref options 'daemon (eq? command-type 'cron)) - (begin - (if (not (eqv? (primitive-fork) 0)) - (quit)) - (setsid) - (if (eq? command-type 'cron) - (with-output-to-file config-pid-file - (lambda () (display (getpid)) (newline)))))) - - - -;; If we are running as cron or crond, we establish a socket to listen for -;; updates from a crontab program. This is put into fd-list so that we can -;; inform the main wait-run-wait execution loop to listen for incoming messages -;; on this socket. - -(define fd-list '()) - -(if (eq? command-type 'cron) - (catch #t - (lambda () - (let ((socket (socket AF_UNIX SOCK_STREAM 0))) - (bind socket AF_UNIX config-socket-file) - (listen socket 5) - (set! fd-list (list socket)))) - (lambda (key . args) - (delete-file config-pid-file) - (mcron-error 1 - "Cannot bind to UNIX socket " - config-socket-file)))) - - - - -;; This function is called whenever a message comes in on the above socket. We -;; read a user name from the socket, dealing with the "/etc/crontab" special -;; case, remove all the user's jobs from the job list, and then re-read the -;; user's updated file. In the special case we drop all the system jobs and -;; re-read the /etc/crontab file. - -(define (process-update-request) - (let* ((socket (car (accept (car fd-list)))) - (user-name (read-line socket))) - (close socket) - (set-configuration-time (current-time)) - (catch-mcron-error - (if (string=? user-name "/etc/crontab") - (begin - (clear-system-jobs) - (use-system-job-list) - (read-vixie-file "/etc/crontab" parse-system-vixie-line) - (use-user-job-list)) - (let ((user (getpw user-name))) - (remove-user-jobs user) - (set-configuration-user user) - (read-vixie-file (string-append config-spool-dir "/" user-name))))))) - - - -;; 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 fd-list. - -(catch-mcron-error - (while #t - (run-job-loop fd-list) - (if (not (null? fd-list)) - (process-update-request)))) |