A modern Music Player Daemon based on Rockbox open source high quality audio player
tsiry-sandratraina.com
libadwaita
audio
rust
zig
deno
mpris
rockbox
mpd
1/*
2FUNCTION
3 <<strncpy>>---counted copy string
4
5INDEX
6 strncpy
7
8ANSI_SYNOPSIS
9 #include <string.h>
10 char *strncpy(char *<[dst]>, const char *<[src]>, size_t <[length]>);
11
12TRAD_SYNOPSIS
13 #include <string.h>
14 char *strncpy(<[dst]>, <[src]>, <[length]>)
15 char *<[dst]>;
16 char *<[src]>;
17 size_t <[length]>;
18
19DESCRIPTION
20 <<strncpy>> copies not more than <[length]> characters from the
21 the string pointed to by <[src]> (including the terminating
22 null character) to the array pointed to by <[dst]>. If the
23 string pointed to by <[src]> is shorter than <[length]>
24 characters, null characters are appended to the destination
25 array until a total of <[length]> characters have been
26 written.
27
28RETURNS
29 This function returns the initial value of <[dst]>.
30
31PORTABILITY
32<<strncpy>> is ANSI C.
33
34<<strncpy>> requires no supporting OS subroutines.
35
36QUICKREF
37 strncpy ansi pure
38*/
39
40#include <string.h>
41#include <limits.h>
42#include "plugin.h"
43#include "_ansi.h"
44#include <stdint.h>
45
46/*SUPPRESS 560*/
47/*SUPPRESS 530*/
48
49/* Nonzero if either X or Y is not aligned on a "long" boundary. */
50#define ROCKBOX_UNALIGNED(X, Y) \
51 (((uintptr_t)X & (sizeof (long) - 1)) | ((uintptr_t)Y & (sizeof (long) - 1)))
52
53#if LONG_MAX == 2147483647L
54#define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080)
55#else
56#if LONG_MAX == 9223372036854775807L
57/* Nonzero if X (a long int) contains a NULL byte. */
58#define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080)
59#else
60#error long int is not a 32bit or 64bit type.
61#endif
62#endif
63
64#ifndef DETECTNULL
65#error long int is not a 32bit or 64bit byte
66#endif
67
68#define TOO_SMALL(LEN) ((LEN) < sizeof (long))
69
70char *
71_DEFUN (strncpy, (dst0, src0),
72 char *dst0 _AND
73 _CONST char *src0 _AND
74 size_t count)
75{
76#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
77 char *dscan;
78 _CONST char *sscan;
79
80 dscan = dst0;
81 sscan = src0;
82 while (count > 0)
83 {
84 --count;
85 if ((*dscan++ = *sscan++) == '\0')
86 break;
87 }
88 while (count-- > 0)
89 *dscan++ = '\0';
90
91 return dst0;
92#else
93 char *dst = dst0;
94 _CONST char *src = src0;
95 long *aligned_dst;
96 _CONST long *aligned_src;
97
98 /* If SRC and DEST is aligned and count large enough, then copy words. */
99 if (!ROCKBOX_UNALIGNED (src, dst) && !TOO_SMALL (count))
100 {
101 aligned_dst = (long*)dst;
102 aligned_src = (long*)src;
103
104 /* SRC and DEST are both "long int" aligned, try to do "long int"
105 sized copies. */
106 while (count >= sizeof (long int) && !DETECTNULL(*aligned_src))
107 {
108 count -= sizeof (long int);
109 *aligned_dst++ = *aligned_src++;
110 }
111
112 dst = (char*)aligned_dst;
113 src = (char*)aligned_src;
114 }
115
116 while (count > 0)
117 {
118 --count;
119 if ((*dst++ = *src++) == '\0')
120 break;
121 }
122
123 while (count-- > 0)
124 *dst++ = '\0';
125
126 return dst0;
127#endif /* not PREFER_SIZE_OVER_SPEED */
128}