use gnulib's progname module

* bootstrap.conf (gnulib_modules): Add progname.
* src/*.c (program_name): Remove declaration.
* (main): Call set_program_name rather than setting program_name.
* src/nice.c (main): Cast program_name to "(char *)".
* src/prog-fprintf.c: Include "system.h"
* src/system.h: Include "progname.h".
* maint.mk (sc_program_name): Adjust rule.
Suggestion from Eric Blake.

1 files changed, 1 insertions, 4 deletions

diff --git a/src/du.c b/src/du.c
index 8b04b65d1..32cb3631d 100644
--- a/src/du.c
+++ b/src/du.c
@@ -126,9 +126,6 @@ struct dulevel
   struct duinfo subdir;
 };
 
-/* Name under which this program was invoked.  */
-char const *program_name;
-
 /* If true, display counts for all files, not just directories.  */
 static bool opt_all = false;
 
@@ -685,7 +682,7 @@ main (int argc, char **argv)
   cwd_only[1] = NULL;
 
   initialize_main (&argc, &argv);
-  program_name = argv[0];
+  set_program_name (argv[0]);
   setlocale (LC_ALL, "");
   bindtextdomain (PACKAGE, LOCALEDIR);
   textdomain (PACKAGE);