xref: /freebsd/contrib/ncurses/ncurses/tinfo/strings.c (revision 21817992b3314c908ab50f0bb88d2ee750b9c4ac)
1 /****************************************************************************
2  * Copyright 2020,2023 Thomas E. Dickey                                     *
3  * Copyright 2000-2012,2017 Free Software Foundation, Inc.                  *
4  *                                                                          *
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6  * copy of this software and associated documentation files (the            *
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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  *                                                                          *
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23  *                                                                          *
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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 
41 MODULE_ID("$Id: strings.c,v 1.11 2023/05/27 20:13:10 tom Exp $")
42 
43 /****************************************************************************
44  * Useful string functions (especially for mvcur)
45  ****************************************************************************/
46 
47 #if !HAVE_STRSTR
NCURSES_EXPORT(char *)48 NCURSES_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  */
71 NCURSES_EXPORT(string_desc *)
_nc_str_init(string_desc * dst,char * src,size_t len)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  */
88 NCURSES_EXPORT(string_desc *)
_nc_str_null(string_desc * dst,size_t len)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  */
97 NCURSES_EXPORT(string_desc *)
_nc_str_copy(string_desc * dst,const string_desc * const src)98 _nc_str_copy(string_desc * dst, const string_desc * const src)
99 {
100     *dst = *src;
101     return dst;
102 }
103 
104 /*
105  * Replaces strcat into a fixed buffer, returning false on failure.
106  */
107 NCURSES_EXPORT(bool)
_nc_safe_strcat(string_desc * dst,const char * src)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  */
128 NCURSES_EXPORT(bool)
_nc_safe_strcpy(string_desc * dst,const char * src)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