all: Separate programs in different executables.

This improves readability and complies with the GNU Coding Standards by
making the behavior of the programs independent of the name used to
invoke them.

* src/mcron/scripts/cron.scm: New file.
* src/mcron/scripts/crontab.scm: Likewise.
* src/mcron/scripts/mcron.scm: Likewise.
* Makefile.am (dist_mcronmodule_DATA): Remove 'src/mcron/crontab.scm'.
(bin_PROGRAMS): Add 'crontab'.
(sbin_PROGRAMS): Add 'cron'.
(mcron_CFLAGS, mcron_LDADD): Rename to ...
(AM_CFLAGS, LDADD): ... these.
(cron_SOURCES, cron_CPPFLAGS, cron_DEPENDENCIES)
(crontab_SOURCES, crontab_CPPFLAGS, crontab_DEPENDENCIES)
(mcron_CPPFLAGS, mcronscriptdir, dist_mcronscript_DATA): New variables.
(modules): Redefine it in terms of other '_DATA' variables.
* src/mcron/crontab.scm: Remove file.
* src/mcron/main.scm (parse-args): New procedure.
(command-name, command-type, options): Remove.
(show-version): Adapt.
(show-help, process-files-in-system-directory, cron-file-descriptors)
(main, process-user-file, process-files-in-user-directory): Move
procedures in the new files.
* src/mcron.c (inner_main): Define the current module at compile time.
* TODO: Update.
* .gitignore: Likewise.

Makefile.am

@@ -16,13 +16,25 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-bin_PROGRAMS = mcron
-mcron_SOURCES = src/mcron.c
-mcron_CFLAGS = @GUILE_CFLAGS@
-mcron_DEPENDENCIES = $(mcronmodule_DATA)
-mcron_LDADD = @GUILE_LIBS@
+bin_PROGRAMS = mcron crontab
+sbin_PROGRAMS = cron
 
-modules = \
+AM_CFLAGS = @GUILE_CFLAGS@
+LDADD = @GUILE_LIBS@
+
+mcron_SOURCES = src/mcron.c
+mcron_CPPFLAGS = -DPROGRAM="\"mcron\""
+mcron_DEPENDENCIES = $(modules:%.scm=%.go)
+
+cron_SOURCES = src/mcron.c
+cron_CPPFLAGS = -DPROGRAM="\"cron\""
+cron_DEPENDENCIES = $(modules:%.scm=%.go)
+
+crontab_SOURCES = src/mcron.c
+crontab_CPPFLAGS = -DPROGRAM="\"crontab\""
+crontab_DEPENDENCIES = $(modules:%.scm=%.go)
+
+dist_mcronmodule_DATA = \
   src/mcron/base.scm \
   src/mcron/environment.scm \
   src/mcron/job-specifier.scm \
@@ -32,13 +44,22 @@ modules = \
   src/mcron/vixie-time.scm
 
 mcronmodule_DATA = \
-  $(modules:%.scm=%.go) \
+  $(dist_mcronmodule_DATA:%.scm=%.go) \
   src/mcron/config.scm \
   src/mcron/config.go
 
-dist_mcronmodule_DATA = \
-  $(modules) \
-  src/mcron/crontab.scm
+mcronscriptdir = $(mcronmoduledir)/scripts
+dist_mcronscript_DATA = \
+  src/mcron/scripts/cron.scm \
+  src/mcron/scripts/crontab.scm \
+  src/mcron/scripts/mcron.scm
+
+mcronscript_DATA = $(dist_mcronscript_DATA:%.scm=%.go)
+
+modules = \
+  $(dist_mcronmodule_DATA) \
+  $(dist_mcronscript_DATA) \
+  src/mcron/config.scm
 
 # Unset 'GUILE_LOAD_COMPILED_PATH' altogether while compiling.  Otherwise, if
 # $GUILE_LOAD_COMPILED_PATH contains $(mcronmoduledir), we may find .go files