ncurses 6.2 - patch 20200321
[ncurses.git] / progs / clear.c
index b813f0e40635a4fbe10e28d454f7dc95945fbb7e..85a5ea541b688217e38d5d09621630d247ffe9f0 100644 (file)
@@ -1,5 +1,6 @@
 /****************************************************************************
- * Copyright (c) 1998 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            *
 /****************************************************************************
  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
+ *     and: Thomas E. Dickey                        1996-on                 *
  ****************************************************************************/
 
-
 /*
  * clear.c --  clears the terminal's screen
  */
 
-#include <progs.priv.h>
+#define USE_LIBTINFO
+#include <clear_cmd.h>
+#include <tty_settings.h>
 
-#include <curses.h>
+MODULE_ID("$Id: clear.c,v 1.23 2020/02/02 23:34:34 tom Exp $")
 
-MODULE_ID("$Id: clear.c,v 1.7 1998/02/11 12:14:02 tom Exp $")
+const char *_nc_progname = "clear";
 
-static int putch(int c)
+static void
+usage(void)
 {
-       return putchar(c);
+#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
+main(
        int argc GCC_UNUSED,
-       char *argv[] GCC_UNUSED)
+       char *argv[]GCC_UNUSED)
 {
-       setupterm((char *) 0, STDOUT_FILENO, (int *) 0);
-       if (clear_screen == (char *) 0)
-               return EXIT_FAILURE;
-       tputs(clear_screen, lines > 0 ? lines : 1, putch);
-       return EXIT_SUCCESS;
+    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, FALSE);
+
+    setupterm(term, fd, (int *) 0);
+
+    ExitProgram((clear_cmd(opt_x) == ERR)
+               ? EXIT_FAILURE
+               : EXIT_SUCCESS);
 }