ncurses 6.2 - patch 20200606
[ncurses.git] / progs / clear.c
index 559d296c3f4c01816c16535a026500416b35e850..85a5ea541b688217e38d5d09621630d247ffe9f0 100644 (file)
@@ -1,5 +1,6 @@
 /****************************************************************************
- * Copyright (c) 1998-2013,2016 Free Software Foundation, Inc.              *
+ * Copyright 2020 Thomas E. Dickey                                          *
+ * Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
  *                                                                          *
  * Permission is hereby granted, free of charge, to any person obtaining a  *
  * copy of this software and associated documentation files (the            *
 #include <clear_cmd.h>
 #include <tty_settings.h>
 
-MODULE_ID("$Id: clear.c,v 1.17 2016/12/24 19:33:39 tom Exp $")
+MODULE_ID("$Id: clear.c,v 1.23 2020/02/02 23:34:34 tom Exp $")
 
 const char *_nc_progname = "clear";
 
+static void
+usage(void)
+{
+#define KEEP(s) s "\n"
+    static const char msg[] =
+    {
+       KEEP("")
+       KEEP("Options:")
+       KEEP("  -T TERM     use this instead of $TERM")
+       KEEP("  -V          print curses-version")
+       KEEP("  -x          do not try to clear scrollback")
+    };
+#undef KEEP
+    (void) fprintf(stderr, "Usage: %s [options]\n", _nc_progname);
+    fputs(msg, stderr);
+    ExitProgram(EXIT_FAILURE);
+}
+
 int
 main(
        int argc GCC_UNUSED,
@@ -51,14 +70,39 @@ main(
 {
     TTY tty_settings;
     int fd;
+    int c;
+    char *term;
+    bool opt_x = FALSE;                /* clear scrollback if possible */
 
     _nc_progname = _nc_rootname(argv[0]);
+    term = getenv("TERM");
+
+    while ((c = getopt(argc, argv, "T:Vx")) != -1) {
+       switch (c) {
+       case 'T':
+           use_env(FALSE);
+           use_tioctl(TRUE);
+           term = optarg;
+           break;
+       case 'V':
+           puts(curses_version());
+           ExitProgram(EXIT_SUCCESS);
+       case 'x':               /* do not try to clear scrollback */
+           opt_x = TRUE;
+           break;
+       default:
+           usage();
+           /* NOTREACHED */
+       }
+    }
+    if (optind < argc)
+       usage();
 
-    fd = save_tty_settings(&tty_settings);
+    fd = save_tty_settings(&tty_settings, FALSE);
 
-    setupterm((char *) 0, fd, (int *) 0);
+    setupterm(term, fd, (int *) 0);
 
-    ExitProgram((clear_cmd() == ERR)
+    ExitProgram((clear_cmd(opt_x) == ERR)
                ? EXIT_FAILURE
                : EXIT_SUCCESS);
 }