1/****************************************************************************
2 * Copyright 2020 Thomas E. Dickey                                          *
3 * Copyright 2000-2012,2017 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: Thomas E. Dickey                                                *
32 ****************************************************************************/
33
34/*
35**	lib_mvcur.c
36**/
37
38#include <curses.priv.h>
39#include <tic.h>
40
41MODULE_ID("$Id: strings.c,v 1.10 2020/02/02 23:34:34 tom Exp $")
42
43/****************************************************************************
44 * Useful string functions (especially for mvcur)
45 ****************************************************************************/
46
47#if !HAVE_STRSTR
48NCURSES_EXPORT(char *)
49_nc_strstr(const char *haystack, const char *needle)
50{
51    size_t len1 = strlen(haystack);
52    size_t len2 = strlen(needle);
53    char *result = 0;
54
55    while ((len1 != 0) && (len1-- >= len2)) {
56	if (!strncmp(haystack, needle, len2)) {
57	    result = (char *) haystack;
58	    break;
59	}
60	haystack++;
61    }
62    return result;
63}
64#endif
65
66/*
67 * Initialize the descriptor so we can append to it.  Note that 'src' may
68 * be a null pointer (see _nc_str_null), so the corresponding strcat and
69 * strcpy calls have to allow for this.
70 */
71NCURSES_EXPORT(string_desc *)
72_nc_str_init(string_desc * dst, char *src, size_t len)
73{
74    if (dst != 0) {
75	dst->s_head = src;
76	dst->s_tail = src;
77	dst->s_size = len - 1;
78	dst->s_init = dst->s_size;
79	if (src != 0)
80	    *src = 0;
81    }
82    return dst;
83}
84
85/*
86 * Initialize the descriptor for only tracking the amount of memory used.
87 */
88NCURSES_EXPORT(string_desc *)
89_nc_str_null(string_desc * dst, size_t len)
90{
91    return _nc_str_init(dst, 0, len);
92}
93
94/*
95 * Copy a descriptor
96 */
97NCURSES_EXPORT(string_desc *)
98_nc_str_copy(string_desc * dst, string_desc * src)
99{
100    *dst = *src;
101    return dst;
102}
103
104/*
105 * Replaces strcat into a fixed buffer, returning false on failure.
106 */
107NCURSES_EXPORT(bool)
108_nc_safe_strcat(string_desc * dst, const char *src)
109{
110    if (PRESENT(src)) {
111	size_t len = strlen(src);
112
113	if (len < dst->s_size) {
114	    if (dst->s_tail != 0) {
115		_nc_STRCPY(dst->s_tail, src, dst->s_size);
116		dst->s_tail += len;
117	    }
118	    dst->s_size -= len;
119	    return TRUE;
120	}
121    }
122    return FALSE;
123}
124
125/*
126 * Replaces strcpy into a fixed buffer, returning false on failure.
127 */
128NCURSES_EXPORT(bool)
129_nc_safe_strcpy(string_desc * dst, const char *src)
130{
131    if (PRESENT(src)) {
132	size_t len = strlen(src);
133
134	if (len < dst->s_size) {
135	    if (dst->s_head != 0) {
136		_nc_STRCPY(dst->s_head, src, dst->s_size);
137		dst->s_tail = dst->s_head + len;
138	    }
139	    dst->s_size = dst->s_init - len;
140	    return TRUE;
141	}
142    }
143    return FALSE;
144}
145