[Bug-mcron] [PATCH 18/33] main: Add (mcron main) module.

[Mathieu Lirzin]

Replace 'ed' hack to eval content of scm/mcron/main.scm in the C wrapper
by executing the C code in the context of (mcron main).

* scm/mcron/main.scm (mcron main): New module.
  (show-version, show-package-information, show-help, main): Remove
  extra newline characters in strings.
* mcron.c.template: Rename to ...
* mcron.c: ... this.
  (inner_main): Set current module to (mcron main).
* makefile.ed: Delete file.
* configure.ac: Remove check for 'ed' program.
* makefile.am, .gitignore: Adjust accordingly.
---
 .gitignore         |   1 -
 configure.ac       |   4 --
 makefile.am        |  12 +-----
 makefile.ed        |  34 ---------------
 mcron.c            | 102 +++++++++++++++++++++++++++++++++++++++++++++
 mcron.c.template   | 120 -----------------------------------------------------
 scm/mcron/main.scm | 108 ++++++++++++++++++++++-------------------------
 7 files changed, 153 insertions(+), 228 deletions(-)
 delete mode 100644 makefile.ed
 create mode 100644 mcron.c
 delete mode 100644 mcron.c.template

diff --git a/.gitignore b/.gitignore
index 6aaa315..4505cc5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -27,7 +27,6 @@ install-sh
 makefile
 makefile.in
 /mcron
-mcron.c
 /mdate-sh
 *.o
 missing
diff --git a/configure.ac b/configure.ac
index a3b84e6..2149e9d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -64,10 +64,6 @@ AC_CHECK_PROGS(HEAD, head)
 if test "x$ac_cv_prog_HEAD" = "x"; then
    AC_MSG_ERROR(head not found)
 fi
-AC_CHECK_PROGS(ED, ed)
-if test "x$ac_cv_prog_ED" = "x"; then
-   AC_MSG_ERROR(ed not found)
-fi
 AC_CHECK_PROGS(WHICH, which)
 if test "x$ac_cv_prog_WHICH" = "x"; then
     AC_MSG_ERROR(which not found)
diff --git a/makefile.am b/makefile.am
index 0717d4d..0031186 100644
--- a/makefile.am
+++ b/makefile.am
@@ -21,12 +21,9 @@
 
 SUBDIRS = scm/mcron .
 
-ED = @ED@   # !!!! Are these needed?
 CP = @CP@
 
-CLEANFILES = mcron.c
-
-EXTRA_DIST = makefile.ed mcron.c.template BUGS
+EXTRA_DIST = BUGS
 
 info_TEXINFOS = doc/mcron.texi
 
@@ -40,13 +37,6 @@ mcron_LDADD = @GUILE_LIBS@
 # in turn so that we can do mcron --help during the build process.
 mcron_CFLAGS  = @GUILE_CFLAGS@ -DGUILE_LOAD_PATH=\"$(datadir):./scm:...\"
 
-
-mcron.c : scm/mcron/main.scm scm/mcron/crontab.scm makefile.ed mcron.c.template
-       @echo 'Building mcron.c...'
-       @$(ED) < makefile.ed > /dev/null 2>&1
-       @rm -f mcron.escaped.scm > /dev/null 2>&1
-
-
 # Full program prefix.
 fpp = $(DESTDIR)$(bindir)/@real_program_prefix@
 
diff --git a/makefile.ed b/makefile.ed
deleted file mode 100644
index 7047ec7..0000000
--- a/makefile.ed
+++ /dev/null
@@ -1,34 +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/>.
-#
-#
-#
-e scm/mcron/main.scm
-/\(load "crontab.scm"\)/d
--1r scm/mcron/crontab.scm
-%s/\\/\\\\/g
-%s/"/\\"/g
-%s/ *;;.*$/ /g
-g/^ *$/d
-%s/^/\"/
-%s/$/\"/
-w mcron.escaped.scm
-e mcron.c.template
-/GUILE_PROGRAM_GOES_HERE/d
--1r mcron.escaped.scm
-w mcron.c
-q
diff --git a/mcron.c b/mcron.c
new file mode 100644
index 0000000..472f096
--- /dev/null
+++ b/mcron.c
@@ -0,0 +1,102 @@
+/* mcron.c -- Run the mcron program.
+
+   Copyright (C) 2015 Mathieu Lirzin
+   Copyright (C) 2003, 2014 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 C code represents the thinnest possible wrapper around the Guile code
+   which constitutes all the functionality of the mcron program.  There are
+   two plus one reasons why we need to do this, and one very unfortunate
+   consequence.
+
+   * Firstly, SUID does not work on an executable script.  In the end, it is
+     the execution of the translator, in our case guile, which determines the
+     effective user, and it is not wise to make the system guile installation
+     SUID root!
+
+   * Secondly, executable scripts show up in ugly ways in listings of the
+     system process table.  Guile in particular, with its multi-line
+     #! ...\ \n -s ...!#
+     idiosyncracies shows up in process listings in a way that is difficult
+     to determine what program is actually running.
+
+   * A third reason for the C wrapper which might be mentioned is that a
+     security-conscious system administrator can choose to only install a
+     binary, thus removing the possibility of a user studying a guile script
+     and working out ways of hacking it to his own ends, or worse still
+     finding a way to modify it to his own ends.
+
+   * Unfortunately, running the guile script from inside a C program means
+     that the sigaction function does not work.  Instead, it is necessary to
+     perform the signal processing in C.  */
+
+#include <libguile.h>
+#include <signal.h>
+#include <string.h>
+
+/* This is a function designed to be installed as a signal handler, for
+   signals which are supposed to initiate shutdown of this program.  It calls
+   the scheme procedure (see mcron.scm for details) to do all the work, and
+   then exits.  */
+
+void
+react_to_terminal_signal (int sig)
+{
+  scm_c_eval_string ("(delete-run-file)");
+  exit (1);
+}
+
+/* This is a function designed to be callable from scheme, and sets up all the
+   signal handlers required by the cron personality.  */
+
+SCM
+set_cron_signals ()
+{
+  static struct sigaction sa;
+
+  memset (&sa, 0, sizeof (sa));
+  sa.sa_handler = react_to_terminal_signal;
+  sigaction (SIGTERM, &sa, 0);
+  sigaction (SIGINT,  &sa, 0);
+  sigaction (SIGQUIT, &sa, 0);
+  sigaction (SIGHUP,  &sa, 0);
+
+  return SCM_BOOL_T;
+}
+
+/* The effective main function (i.e. the one that actually does some work).
+   We register the function above with the guile system, and then execute the
+   mcron guile program.  */
+
+void
+inner_main (void *closure, int argc, char **argv)
+{
+  scm_set_current_module (scm_c_resolve_module ("mcron main"));
+  scm_c_define_gsubr ("c-set-cron-signals", 0, 0, 0, set_cron_signals);
+  scm_c_eval_string ("(main)");
+}
+
+/* The real main function.  Does nothing but start up the guile subsystem. */
+
+int
+main (int argc, char **argv)
+{
+  setenv ("GUILE_LOAD_PATH", GUILE_LOAD_PATH, 1);
+  scm_boot_guile (argc, argv, inner_main, 0);
+
+  return 0;
+}
diff --git a/mcron.c.template b/mcron.c.template
deleted file mode 100644
index e9a755d..0000000
--- a/mcron.c.template
+++ /dev/null
@@ -1,120 +0,0 @@
-/*                                                   -*-c-*- */
-/*
- *   Copyright (C) 2003, 2014 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 C code represents the thinnest possible wrapper around the Guile code
-    which constitutes all the functionality of the mcron program. There are two
-    plus one reasons why we need to do this, and one very unfortunate
-    consequence.
-
-        Firstly, SUID does not work on an executable script. In the end, it is
-        the execution of the translator, in our case guile, which determines 
the
-        effective user, and it is not wise to make the system guile 
installation
-        SUID root!
-
-        Secondly, executable scripts show up in ugly ways in listings of the
-        system process table. Guile in particular, with its multi-line
-        #! ...\ \n -s ...!#
-        idiosyncracies shows up in process listings in a way that is difficult
-        to determine what program is actually running.
-
-        A third reason for the C wrapper which might be mentioned is that a
-        security-conscious system administrator can choose to only install a
-        binary, thus removing the possibility of a user studying a guile script
-        and working out ways of hacking it to his own ends, or worse still
-        finding a way to modify it to his own ends.
-
-        Unfortunately, running the guile script from inside a C program means
-        that the sigaction function does not work. Instead, it is necessary to
-        perform the signal processing in C.
-
-    The guile code itself is substituted for the GU1LE_PROGRAM_GOES_HERE (sic)
-    token by the makefile, which processes the scheme to make it look like one
-    big string.
-*/
-
-
-
-#include <string.h>
-#include <signal.h>
-#include <libguile.h>
-
-
-
-/* This is a function designed to be installed as a signal handler, for signals
-   which are supposed to initiate shutdown of this program. It calls the scheme
-   procedure (see mcron.scm for details) to do all the work, and then exits. */
-
-void
-react_to_terminal_signal (int sig)
-{
-  scm_c_eval_string ("(delete-run-file)");
-  exit (1);
-}
-
-
-
-/* This is a function designed to be callable from scheme, and sets up all the
-   signal handlers required by the cron personality.  */
-
-SCM
-set_cron_signals ()
-{
-  static struct sigaction sa;
-  memset (&sa, 0, sizeof (sa));
-  sa.sa_handler = react_to_terminal_signal;
-  sigaction (SIGTERM, &sa, 0);
-  sigaction (SIGINT,  &sa, 0);
-  sigaction (SIGQUIT, &sa, 0);
-  sigaction (SIGHUP,  &sa, 0);
-  
-  return SCM_BOOL_T;
-}
-
-
-
-/* The effective main function (i.e. the one that actually does some work). We
-   register the function above with the guile system, and then execute the 
mcron
-   guile program. */
-
-void
-inner_main ()
-{
-  scm_c_define_gsubr ("c-set-cron-signals", 0, 0, 0, set_cron_signals);
-    
-  scm_c_eval_string (
-                     GUILE_PROGRAM_GOES_HERE
-                     );
-}
-
-
-
-/* The real main function. Does nothing but start up the guile subsystem. */
-
-int
-main (int argc, char **argv)
-{
-  setenv ("GUILE_LOAD_PATH", GUILE_LOAD_PATH, 1);
-  
-  scm_boot_guile (argc, argv, inner_main, 0);
-  
-  return 0;
-}
diff --git a/scm/mcron/main.scm b/scm/mcron/main.scm
index 6a75be4..c03ccfc 100644
--- a/scm/mcron/main.scm
+++ b/scm/mcron/main.scm
@@ -16,28 +16,22 @@
 ;;   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.
-
-(use-modules (ice-9 getopt-long)
-             (ice-9 rdelim)
-             (ice-9 regex)
-             (mcron config)
-             (mcron core)
-             (mcron job-specifier)
-             (mcron vixie-specification)
-             (srfi srfi-2)
-             (srfi srfi-26))
+;;; This is the 'main' routine for the whole system; this module is the global
+;;; entry point (after the minimal C wrapper); to all intents and purposes the
+;;; program is pure Guile and starts here.
+
+(define-module (mcron main)
+  #:use-module (ice-9 getopt-long)
+  #:use-module (ice-9 rdelim)
+  #:use-module (ice-9 regex)
+  #:use-module (mcron config)
+  #:use-module (mcron core)
+  #:use-module (mcron job-specifier)
+  #:use-module (mcron vixie-specification)
+  #:use-module (srfi srfi-2)
+  #:use-module (srfi srfi-26)
+  #:export (delete-run-file
+           main))
 
 (define* (command-name #:optional (command (car (command-line))))
   "Extract the actual command name from COMMAND.  This returns the last part
@@ -112,18 +106,18 @@ and exit with its error code."
   (let* ((name       config-package-name)
          (short-name (cadr (string-split name #\space)))
          (version    config-package-version))
-    (simple-format #t "~a (~a) ~a\n
-Copyright (C) 2015 the ~a authors.\n
-License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>\n
-This is free software: you are free to change and redistribute it.\n
+    (simple-format #t "~a (~a) ~a
+Copyright (C) 2015 the ~a authors.
+License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
+This is free software: you are free to change and redistribute it.
 There is NO WARRANTY, to the extent permitted by law.\n"
                   command name version short-name)
     (quit)))
 
 (define (show-package-information)
   "Display where to get help and send bug reports."
-  (simple-format #t "\nReport bugs to: ~a.\n
-~a home page: <~a>\n
+  (simple-format #t "\nReport bugs to: ~a.
+~a home page: <~a>
 General help using GNU software: <http://www.gnu.org/gethelp/>\n"
                 config-package-bugreport
                 config-package-name
@@ -135,34 +129,34 @@ General help using GNU software: 
<http://www.gnu.org/gethelp/>\n"
   (display
    (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
+      " [OPTIONS] [FILES]
+Run an mcron process according to the specifications in the FILES (`-' for
+standard input), or use all the files in ~/.config/cron (or the
+deprecated ~/.cron) with .guile or .vixie extensions.
+
+  -v, --version             Display version
+  -h, --help                Display this help message
+  -sN, --schedule[=]N       Display the next N jobs that will be run by mcron
+  -d, --daemon              Immediately detach the program from the terminal
+                              and run as a daemon process
+  -i, --stdin=(guile|vixie) Format of data passed as standard input or
                               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
+      " [OPTIONS]
+Unless an option is specified, run a cron daemon as a detached process,
+reading all the information in the users' crontabs and in /etc/crontab.
+
+  -v, --version             Display version
+  -h, --help                Display this help message
+  -sN, --schedule[=]N       Display the next N jobs that will be run by cron
+  -n, --noetc               Do not check /etc/crontab for updates (HIGHLY
                               RECOMMENDED).")
      ((crontab)
-      " [-u user] file\n
-       crontab [-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
+      " [-u user] file
+       crontab [-u user] { -e | -l | -r }
+               (default operation is replace, per 1003.2)
+       -e      (edit user's crontab)
+       -l      (list user's crontab)
        -r      (delete user's crontab")
      (else "\nrubbish")))
   (newline)
@@ -379,10 +373,10 @@ comes in on the above socket."
                                          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
+       (display "\
+WARNING: cron will check for updates to /etc/crontab EVERY MINUTE. If you do
+not use this file, or you are prepared to manually restart cron whenever you
+make a change, then it is HIGHLY RECOMMENDED that you use the --noetc
 option.\n")
        (set-configuration-user "root")
        (job '(- (next-minute-from (next-minute)) 6)
@@ -423,5 +417,3 @@ option.\n")
        (run-job-loop fdes-list)
        (unless (null? fdes-list)
          (process-update-request fdes-list))))))
-
-(main)