strings.c revision 66963 
1/****************************************************************************
2 * Copyright (c) 2000 Free Software Foundation, Inc.                        *
3 *                                                                          *
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11 *                                                                          *
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14 *                                                                          *
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22 *                                                                          *
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28
29/****************************************************************************
30 *  Author: Thomas E. Dickey                                                *
31 ****************************************************************************/
32
33/*
34**	lib_mvcur.c
35**/
36
37#include <curses.priv.h>
38
39MODULE_ID("$Id")
40
41/****************************************************************************
42 * Useful string functions (especially for mvcur)
43 ****************************************************************************/
44
45#if !HAVE_STRSTR
46char *
47_nc_strstr(const char *haystack, const char *needle)
48{
49    size_t len1 = strlen(haystack);
50    size_t len2 = strlen(needle);
51    char *result = 0;
52
53    while ((len1 != 0) && (len1-- >= len2)) {
54	if (!strncmp(haystack, needle, len2)) {
55	    result = haystack;
56	    break;
57	}
58	haystack++;
59    }
60    return result;
61}
62#endif
63
64/*
65 * Initialize the descriptor so we can append to it.
66 */
67string_desc *
68_nc_str_init(string_desc * dst, char *src, size_t len)
69{
70    if (dst != 0) {
71	dst->s_head = src;
72	dst->s_tail = src;
73	dst->s_size = len - 1;
74	if (src != 0)
75	    *src = 0;
76    }
77    return dst;
78}
79
80/*
81 * Initialize the descriptor for only tracking the amount of memory used.
82 */
83string_desc *
84_nc_str_null(string_desc * dst, size_t len)
85{
86    return _nc_str_init(dst, 0, len);
87}
88
89/*
90 * Copy a descriptor
91 */
92string_desc *
93_nc_str_copy(string_desc * dst, string_desc * src)
94{
95    *dst = *src;
96    return dst;
97}
98
99/*
100 * Replaces strcat into a fixed buffer, returning false on failure.
101 */
102bool
103_nc_safe_strcat(string_desc * dst, const char *src)
104{
105    if (src != 0) {
106	size_t len = strlen(src);
107
108	if (len < dst->s_size) {
109	    if (dst->s_tail != 0) {
110		strcpy(dst->s_tail, src);
111		dst->s_tail += len;
112	    }
113	    dst->s_size -= len;
114	    return TRUE;
115	}
116    }
117    return FALSE;
118}
119
120/*
121 * Replaces strcpy into a fixed buffer, returning false on failure.
122 */
123bool
124_nc_safe_strcpy(string_desc * dst, const char *src)
125{
126    if (src != 0) {
127	size_t len = strlen(src);
128
129	if (len < dst->s_size) {
130	    if (dst->s_head != 0) {
131		strcpy(dst->s_head, src);
132		dst->s_tail = dst->s_head + len;
133	    }
134	    dst->s_size -= len;
135	    return TRUE;
136	}
137    }
138    return FALSE;
139}
140