wrapper: Move 'wrap_env_path' to a new 'utils' module.

* src/wrapper.c: Move 'wrap_env_path' to ...
* src/utils.h: ... here.  New module.
* src/utils.c: New file.
* configure.ac: Use AC_PROG_RANLIB and AM_PROG_AR.
* Makefile.am (noinst_LIBRARIES, src_libmcron_a_SOURCES): New variables.
(LDADD): Add 'src/libmcron.a'.

.gitignore

@@ -1,6 +1,6 @@
+*.[oa]
 *.go
 *.log
-*.o
 *.trs
 *~
 .deps
@@ -8,6 +8,7 @@
 /bin/cron
 /bin/crontab
 /bin/mcron
+/build-aux/ar-lib
 /build-aux/compile
 /build-aux/config.guess
 /build-aux/config.sub

Makefile.am

@@ -36,7 +36,7 @@ AM_CPPFLAGS = \
   -D_GNU_SOURCE
 
 AM_CFLAGS = @GUILE_CFLAGS@
-LDADD = @GUILE_LIBS@
+LDADD = @GUILE_LIBS@ src/libmcron.a
 
 bin_mcron_SOURCES = src/wrapper.c
 bin_mcron_CPPFLAGS = $(AM_CPPFLAGS) -DPROGRAM="\"mcron\""
@@ -53,6 +53,12 @@ bin_crontab_DEPENDENCIES = $(compiled_modules)
 # wrapper to be used in the build environment and for running tests.
 noinst_SCRIPTS = pre-inst-env
 
+# local library.
+noinst_LIBRARIES = src/libmcron.a
+src_libmcron_a_SOURCES = \
+  src/utils.c \
+  src/utils.h
+
 ## --------------- ##
 ## Guile modules.  ##
 ## --------------- ##

configure.ac

@@ -33,6 +33,8 @@ AC_CANONICAL_HOST
 AC_PROG_AWK
 AC_PROG_EGREP
 AM_PROG_CC_C_O
+AC_PROG_RANLIB
+AM_PROG_AR
 
 # Check for Guile 2.x. development files
 GUILE_PKG([2.2 2.0])

src/utils.c

@@ -0,0 +1,44 @@
+/* utils.c -- Utility functions.
+   Copyright © 2017 Mathieu Lirzin <mthl@gnu.org>
+
+   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/>.  */
+
+#include "utils.h"
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void
+wrap_env_path (const char *envar, const char *dir)
+{
+  const char *path = getenv (envar);
+  if (path == NULL)
+    setenv (envar, dir, true);
+  else
+    {
+      char *new_path;
+      int ret = asprintf (&new_path, "%s:%s", dir, path);
+      if (ret >= 0)
+        setenv (envar, new_path, true);
+      else
+        {
+          perror (envar);
+          exit (EXIT_FAILURE);
+        }
+      free (new_path);
+    }
+}

src/utils.h

@@ -0,0 +1,27 @@
+/* utils.h -- Utility functions.
+   Copyright © 2017 Mathieu Lirzin <mthl@gnu.org>
+
+   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/>.  */
+
+#ifndef MCRON_UTILS_H
+#define MCRON_UTILS_H
+
+/**
+   Append DIR in front of ENVAR environment variable value.  If ENVAR is not
+   defined, then define it with DIR.  Bail out if something went wrong.  */
+extern void wrap_env_path (const char *envar, const char *dir);
+
+#endif /* MCRON_UTILS_H */

src/wrapper.c

@@ -21,6 +21,7 @@
    is needed because the crontab personality requires SUID which is not
    permitted for executable scripts.  */
 
+#include "utils.h"
 #include <libguile.h>
 #include <signal.h>
 #include <stdbool.h>
@@ -29,7 +30,6 @@
 #include <string.h>
 
 /* Forward declarations.  */
-static void wrap_env_path (const char *envar, const char *dir);
 static void inner_main (void *closure, int argc, char **argv);
 static void react_to_terminal_signal (int sig);
 static SCM set_cron_signals (void);
@@ -51,29 +51,6 @@ main (int argc, char **argv)
   return EXIT_SUCCESS;
 }
 
-/* Append DIR in front of ENVAR environment variable value.  If ENVAR is not
-   defined, then define it with DIR.  Bail out if something went wrong.  */
-static void
-wrap_env_path (const char *envar, const char *dir)
-{
-  const char *path = getenv (envar);
-  if (path == NULL)
-    setenv (envar, dir, true);
-  else
-    {
-      char *new_path;
-      int ret = asprintf (&new_path, "%s:%s", dir, path);
-      if (ret >= 0)
-        setenv (envar, new_path, true);
-      else
-        {
-          perror (envar);
-          exit (EXIT_FAILURE);
-        }
-      free (new_path);
-    }
-}
-
 /* Launch the Mcron Guile main program.  */
 static void
 inner_main (void *closure, int argc, char **argv)