1/****************************************************************************
2 * Copyright 2020 Thomas E. Dickey                                          *
3 * Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
4 *                                                                          *
5 * Permission is hereby granted, free of charge, to any person obtaining a  *
6 * copy of this software and associated documentation files (the            *
7 * "Software"), to deal in the Software without restriction, including      *
8 * without limitation the rights to use, copy, modify, merge, publish,      *
9 * distribute, distribute with modifications, sublicense, and/or sell       *
10 * copies of the Software, and to permit persons to whom the Software is    *
11 * furnished to do so, subject to the following conditions:                 *
12 *                                                                          *
13 * The above copyright notice and this permission notice shall be included  *
14 * in all copies or substantial portions of the Software.                   *
15 *                                                                          *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
19 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
20 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
21 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
22 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
23 *                                                                          *
24 * Except as contained in this notice, the name(s) of the above copyright   *
25 * holders shall not be used in advertising or otherwise to promote the     *
26 * sale, use or other dealings in this Software without prior written       *
27 * authorization.                                                           *
28 ****************************************************************************/
29
30/****************************************************************************
31 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
32 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
33 *     and: Thomas E. Dickey                        1996-on                 *
34 ****************************************************************************/
35
36/*
37 * clear.c --  clears the terminal's screen
38 */
39
40#define USE_LIBTINFO
41#include <clear_cmd.h>
42#include <tty_settings.h>
43
44MODULE_ID("$Id: clear.c,v 1.23 2020/02/02 23:34:34 tom Exp $")
45
46const char *_nc_progname = "clear";
47
48static void
49usage(void)
50{
51#define KEEP(s) s "\n"
52    static const char msg[] =
53    {
54	KEEP("")
55	KEEP("Options:")
56	KEEP("  -T TERM     use this instead of $TERM")
57	KEEP("  -V          print curses-version")
58	KEEP("  -x          do not try to clear scrollback")
59    };
60#undef KEEP
61    (void) fprintf(stderr, "Usage: %s [options]\n", _nc_progname);
62    fputs(msg, stderr);
63    ExitProgram(EXIT_FAILURE);
64}
65
66int
67main(
68	int argc GCC_UNUSED,
69	char *argv[]GCC_UNUSED)
70{
71    TTY tty_settings;
72    int fd;
73    int c;
74    char *term;
75    bool opt_x = FALSE;		/* clear scrollback if possible */
76
77    _nc_progname = _nc_rootname(argv[0]);
78    term = getenv("TERM");
79
80    while ((c = getopt(argc, argv, "T:Vx")) != -1) {
81	switch (c) {
82	case 'T':
83	    use_env(FALSE);
84	    use_tioctl(TRUE);
85	    term = optarg;
86	    break;
87	case 'V':
88	    puts(curses_version());
89	    ExitProgram(EXIT_SUCCESS);
90	case 'x':		/* do not try to clear scrollback */
91	    opt_x = TRUE;
92	    break;
93	default:
94	    usage();
95	    /* NOTREACHED */
96	}
97    }
98    if (optind < argc)
99	usage();
100
101    fd = save_tty_settings(&tty_settings, FALSE);
102
103    setupterm(term, fd, (int *) 0);
104
105    ExitProgram((clear_cmd(opt_x) == ERR)
106		? EXIT_FAILURE
107		: EXIT_SUCCESS);
108}
109