1 /*
2  * Copyright 2009-2020 Max Kellermann <max.kellermann@gmail.com>
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * - Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  *
11  * - Redistributions in binary form must reproduce the above copyright
12  * notice, this list of conditions and the following disclaimer in the
13  * documentation and/or other materials provided with the
14  * distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
19  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
20  * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
27  * OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #ifndef STRING_STRIP_HXX
31 #define STRING_STRIP_HXX
32 
33 #include "Compiler.h"
34 
35 #include <cstddef>
36 
37 /**
38  * Skips whitespace at the beginning of the string, and returns the
39  * first non-whitespace character.  If the string has no
40  * non-whitespace characters, then a pointer to the NULL terminator is
41  * returned.
42  */
43 gcc_pure gcc_returns_nonnull gcc_nonnull_all
44 const char *
45 StripLeft(const char *p) noexcept;
46 
47 gcc_pure gcc_returns_nonnull gcc_nonnull_all
48 static inline char *
StripLeft(char * p)49 StripLeft(char *p) noexcept
50 {
51 	return const_cast<char *>(StripLeft((const char *)p));
52 }
53 
54 /**
55  * Skips whitespace at the beginning of the string, and returns the
56  * first non-whitespace character or the end pointer.
57  */
58 gcc_pure gcc_returns_nonnull gcc_nonnull_all
59 const char *
60 StripLeft(const char *p, const char *end) noexcept;
61 
62 /**
63  * Determine the string's end as if it was stripped on the right side.
64  */
65 gcc_pure gcc_returns_nonnull gcc_nonnull_all
66 const char *
67 StripRight(const char *p, const char *end) noexcept;
68 
69 /**
70  * Determine the string's end as if it was stripped on the right side.
71  */
72 gcc_pure gcc_returns_nonnull gcc_nonnull_all
73 static inline char *
StripRight(char * p,char * end)74 StripRight(char *p, char *end) noexcept
75 {
76 	return const_cast<char *>(StripRight((const char *)p,
77 					     (const char *)end));
78 }
79 
80 /**
81  * Determine the string's length as if it was stripped on the right
82  * side.
83  */
84 gcc_pure gcc_nonnull_all
85 std::size_t
86 StripRight(const char *p, std::size_t length) noexcept;
87 
88 /**
89  * Strip trailing whitespace by null-terminating the string.
90  */
91 gcc_nonnull_all
92 void
93 StripRight(char *p) noexcept;
94 
95 /**
96  * Skip whitespace at the beginning and terminate the string after the
97  * last non-whitespace character.
98  */
99 gcc_returns_nonnull gcc_nonnull_all
100 char *
101 Strip(char *p) noexcept;
102 
103 #endif
104