ncurses 6.1 - patch 20180317
[ncurses.git] / progs / clear.c
index 417c2446b7a9c6bd051b84be7127d2f017efc50c..2ffdf9530948194d7e6a66c562a4a9a812b480a7 100644 (file)
+/****************************************************************************
+ * Copyright (c) 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            *
+ * "Software"), to deal in the Software without restriction, including      *
+ * without limitation the rights to use, copy, modify, merge, publish,      *
+ * distribute, distribute with modifications, sublicense, and/or sell       *
+ * copies of the Software, and to permit persons to whom the Software is    *
+ * furnished to do so, subject to the following conditions:                 *
+ *                                                                          *
+ * The above copyright notice and this permission notice shall be included  *
+ * in all copies or substantial portions of the Software.                   *
+ *                                                                          *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
+ * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
+ * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
+ *                                                                          *
+ * Except as contained in this notice, the name(s) of the above copyright   *
+ * holders shall not be used in advertising or otherwise to promote the     *
+ * sale, use or other dealings in this Software without prior written       *
+ * authorization.                                                           *
+ ****************************************************************************/
 
-/***************************************************************************
-*                            COPYRIGHT NOTICE                              *
-****************************************************************************
-*                ncurses is copyright (C) 1992-1995                        *
-*                          Zeyd M. Ben-Halim                               *
-*                          zmbenhal@netcom.com                             *
-*                          Eric S. Raymond                                 *
-*                          esr@snark.thyrsus.com                           *
-*                                                                          *
-*        Permission is hereby granted to reproduce and distribute ncurses  *
-*        by any means and for any fee, whether alone or as part of a       *
-*        larger distribution, in source or in binary form, PROVIDED        *
-*        this notice is included with any such distribution, and is not    *
-*        removed from any of its header files. Mention of ncurses in any   *
-*        applications linked with it is highly appreciated.                *
-*                                                                          *
-*        ncurses comes AS IS with no warranty, implied or expressed.       *
-*                                                                          *
-***************************************************************************/
-
+/****************************************************************************
+ *  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 1.22 2017/10/07 21:48:32 tom Exp $")
 
-MODULE_ID("$Id: clear.c,v 1.6 1996/12/21 17:35:11 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);
 }