C++实现ini文件读写的示例代码

目录

• 介绍
• 1.使用INIReader.h头文件
• 1.INIReader.h
• 2.test.ini
• 3.INIReaderTest.cpp
• 2.使用ini.h头文件
• 1.ini.h
• 2.config.ini
• 3.example.cpp
• 3.使用inipp.h头文件
• 3.1 解析算法
• 3.2 默认section算法
• 3.3 Interpolation算法
• 3.4 代码实现

介绍

一般的ini配置文件由节、键、值组成。

【参数】（键=值），例如 :key=value;

【节】：所有的参数都是以节（section）为单位结合在一起的。所有的section名称都是独占一行，并且section名字都被方括号包围着（[XXX]）。在section声明后的所有parameters都属于该section。

例如：[section1]

所以一个包含节，键，值的简单ini配置文件，例如：

[port]
portName=port1
port=123

1.使用INIReader.h头文件

1.INIReader.h

// Read an INI file into easy-to-access name/value pairs.

// inih and INIReader are released under the New BSD license (see LICENSE.txt).
// Go to the project home page for more info:
//
// https://github.com/benhoyt/inih
/* inih -- simple .INI file parser
inih is released under the New BSD license (see LICENSE.txt). Go to the project
home page for more info:
https://github.com/benhoyt/inih
*/

#ifndef __INI_H__
#define __INI_H__

/* Make this header file easier to include in C++ code */
#ifdef __cplusplus
extern "C" {
#endif

#include 

/* Typedef for prototype of handler function. */
typedef int (*ini_handler)(void* user, const char* section,
                           const char* name, const char* value);

/* Typedef for prototype of fgets-style reader function. */
typedef char* (*ini_reader)(char* str, int num, void* stream);

/* Parse given INI-style file. May have [section]s, name=value pairs
   (whitespace stripped), and comments starting with ';' (semicolon). Section
   is "" if name=value pair parsed before any section heading. name:value
   pairs are also supported as a concession to Python's configparser.
   For each name=value pair parsed, call handler function with given user
   pointer as well as section, name, and value (data only valid for duration
   of handler call). Handler should return nonzero on success, zero on error.
   Returns 0 on success, line number of first error on parse error (doesn't
   stop on first error), -1 on file open error, or -2 on memory allocation
   error (only when INI_USE_STACK is zero).
*/
int ini_parse(const char* filename, ini_handler handler, void* user);

/* Same as ini_parse(), but takes a FILE* instead of filename. This doesn't
   close the file when it's finished -- the caller must do that. */
int ini_parse_file(FILE* file, ini_handler handler, void* user);

/* Same as ini_parse(), but takes an ini_reader function pointer instead of
   filename. Used for implementing custom or string-based I/O. */
int ini_parse_stream(ini_reader reader, void* stream, ini_handler handler,
                     void* user);

/* Nonzero to allow multi-line value parsing, in the style of Python's
   configparser. If allowed, ini_parse() will call the handler with the same
   name for each subsequent line parsed. */
#ifndef INI_ALLOW_MULTILINE
#define INI_ALLOW_MULTILINE 1
#endif

/* Nonzero to allow a UTF-8 BOM sequence (0xEF 0xBB 0xBF) at the start of
   the file. See http://code.google.com/p/inih/issues/detail?id=21 */
#ifndef INI_ALLOW_BOM
#define INI_ALLOW_BOM 1
#endif

/* Nonzero to allow inline comments (with valid inline comment characters
   specified by INI_INLINE_COMMENT_PREFIXES). Set to 0 to turn off and match
   Python 3.2+ configparser behaviour. */
#ifndef INI_ALLOW_INLINE_COMMENTS
#define INI_ALLOW_INLINE_COMMENTS 1
#endif
#ifndef INI_INLINE_COMMENT_PREFIXES
#define INI_INLINE_COMMENT_PREFIXES ";"
#endif

/* Nonzero to use stack, zero to use heap (malloc/free). */
#ifndef INI_USE_STACK
#define INI_USE_STACK 1
#endif

/* Stop parsing on first error (default is to keep parsing). */
#ifndef INI_STOP_ON_FIRST_ERROR
#define INI_STOP_ON_FIRST_ERROR 0
#endif

/* Maximum line length for any line in INI file. */
#ifndef INI_MAX_LINE
#define INI_MAX_LINE 200
#endif

#ifdef __cplusplus
}
#endif

/* inih -- simple .INI file parser
inih is released under the New BSD license (see LICENSE.txt). Go to the project
home page for more info:
https://github.com/benhoyt/inih
*/

#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
#define _CRT_SECURE_NO_WARNINGS
#endif

#include 
#include 
#include 

#if !INI_USE_STACK
#include 
#endif

#define MAX_SECTION 50
#define MAX_NAME 50

/* Strip whitespace chars off end of given string, in place. Return s. */
inline static char* rstrip(char* s)
{
    char* p = s + strlen(s);
    while (p > s && isspace((unsigned char)(*--p)))
        *p = '\0';
    return s;
}

/* Return pointer to first non-whitespace char in given string. */
inline static char* lskip(const char* s)
{
    while (*s && isspace((unsigned char)(*s)))
        s++;
    return (char*)s;
}

/* Return pointer to first char (of chars) or inline comment in given string,
   or pointer to null at end of string if neither found. Inline comment must
   be prefixed by a whitespace character to register as a comment. */
inline static char* find_chars_or_comment(const char* s, const char* chars)
{
#if INI_ALLOW_INLINE_COMMENTS
    int was_space = 0;
    while (*s && (!chars || !strchr(chars, *s)) &&
           !(was_space && strchr(INI_INLINE_COMMENT_PREFIXES, *s))) {
        was_space = isspace((unsigned char)(*s));
        s++;
    }
#else
    while (*s && (!chars || !strchr(chars, *s))) {
        s++;
    }
#endif
    return (char*)s;
}

/* Version of strncpy that ensures dest (size bytes) is null-terminated. */
inline static char* strncpy0(char* dest, const char* src, size_t size)
{
    strncpy(dest, src, size);
    dest[size - 1] = '\0';
    return dest;
}

/* See documentation in header file. */
inline int ini_parse_stream(ini_reader reader, void* stream, ini_handler handler,
                     void* user)
{
    /* Uses a fair bit of stack (use heap instead if you need to) */
#if INI_USE_STACK
    char line[INI_MAX_LINE];
#else
    char* line;
#endif
    char section[MAX_SECTION] = "";
    char prev_name[MAX_NAME] = "";

    char* start;
    char* end;
    char* name;
    char* value;
    int lineno = 0;
    int error = 0;

#if !INI_USE_STACK
    line = (char*)malloc(INI_MAX_LINE);
    if (!line) {
        return -2;
    }
#endif

    /* Scan through stream line by line */
    while (reader(line, INI_MAX_LINE, stream) != NULL) {
        lineno++;

        start = line;
#if INI_ALLOW_BOM
        if (lineno == 1 && (unsigned char)start[0] == 0xEF &&
                           (unsigned char)start[1] == 0xBB &&
                           (unsigned char)start[2] == 0xBF) {
            start += 3;
        }
#endif
        start = lskip(rstrip(start));

        if (*start == ';' || *start == '#') {
            /* Per Python configparser, allow both ; and # comments at the
               start of a line */
        }
#if INI_ALLOW_MULTILINE
        else if (*prev_name && *start && start > line) {

#if INI_ALLOW_INLINE_COMMENTS
        end = find_chars_or_comment(start, NULL);
        if (*end)
            *end = '\0';
        rstrip(start);
#endif

            /* Non-blank line with leading whitespace, treat as continuation
               of previous name's value (as per Python configparser). */
            if (!handler(user, section, prev_name, start) && !error)
                error = lineno;
        }
#endif
        else if (*start == '[') {
            /* A "[section]" line */
            end = find_chars_or_comment(start + 1, "]");
            if (*end == ']') {
                *end = '\0';
                strncpy0(section, start + 1, sizeof(section));
                *prev_name = '\0';
            }
            else if (!error) {
                /* No ']' found on section line */
                error = lineno;
            }
        }
        else if (*start) {
            /* Not a comment, must be a name[=:]value pair */
            end = find_chars_or_comment(start, "=:");
            if (*end == '=' || *end == ':') {
                *end = '\0';
                name = rstrip(start);
                value = lskip(end + 1);
#if INI_ALLOW_INLINE_COMMENTS
                end = find_chars_or_comment(value, NULL);
                if (*end)
                    *end = '\0';
#endif
                rstrip(value);

                /* Valid name[=:]value pair found, call handler */
                strncpy0(prev_name, name, sizeof(prev_name));
                if (!handler(user, section, name, value) && !error)
                    error = lineno;
            }
            else if (!error) {
                /* No '=' or ':' found on name[=:]value line */
                error = lineno;
            }
        }

#if INI_STOP_ON_FIRST_ERROR
        if (error)
            break;
#endif
    }

#if !INI_USE_STACK
    free(line);
#endif

    return error;
}

/* See documentation in header file. */
inline int ini_parse_file(FILE* file, ini_handler handler, void* user)
{
    return ini_parse_stream((ini_reader)fgets, file, handler, user);
}

/* See documentation in header file. */
inline int ini_parse(const char* filename, ini_handler handler, void* user)
{
    FILE* file;
    int error;

    file = fopen(filename, "r");
    if (!file)
        return -1;
    error = ini_parse_file(file, handler, user);
    fclose(file);
    return error;
}

#endif /* __INI_H__ */


#ifndef __INIREADER_H__
#define __INIREADER_H__

#include 

2.test.ini

3.INIReaderTest.cpp

// Example that shows simple usage of the INIReader class

#include 
#include 
#include "INIReader.h"

std::string sections(INIReader &reader)
{
    std::stringstream ss;
    std::set sections = reader.Sections();
    for (std::set::iterator it = sections.begin(); it != sections.end(); ++it)
        ss << *it << ",";
    return ss.str();
}

int main()
{
    INIReader reader("test.ini");

    if (reader.ParseError() < 0) {
        std::cout << "Can't load 'test.ini'\n";
        return 1;
    }
    std::cout << "Config loaded from 'test.ini': found sections=" << sections(reader)
              << " version="
              << reader.GetInteger("protocol", "version", -1) << ", name="
              << reader.Get("user", "name", "UNKNOWN") << ", email="
              << reader.Get("user", "email", "UNKNOWN") << ", multi="
              << reader.Get("user", "multi", "UNKNOWN") << ", pi="
              << reader.GetReal("user", "pi", -1) << ", active="
              << reader.GetBoolean("user", "active", true) << "\n";
    return 0;
}

2.使用ini.h头文件

现代 c++ 的另一个 .ini 解析器（为 cpp17 制作），灵感来自 inih 并进行了扩展。

1.ini.h

/**
 * Yet another .ini parser for modern c++ (made for cpp17), inspired and extend
 * from @benhoyt's inih. See project page: https://github.com/SSARCandy/ini-cpp
 */

#ifndef __INI_H__
#define __INI_H__

#include 
#include 
#include 
#include 

#include 
#include 
#include 
#include 
#include 
#include 
#include 

2.config.ini

3.example.cpp

#include 
#include 
#include 
#include 

#include "ini/ini.h"
using namespace inih;

namespace bc = boost::core;

int main() {
    INIReader r{"./test/fixtures/config.ini"};

    const auto& v1 = r.Get("section1", "any");
    const auto& v2 = r.Get("section1", "any");
    const auto& v3 = r.Get("section1", "any");
    const auto& v4 = r.GetVector("section2", "any_vec");
    const auto& v5{r.GetVector("section2", "any_vec")};

    /** output
     * v1 = "1"             type: std::string
     * v2 = 1               type: int
     * v3 = 1.0             type: double
     * v4 = [1, 2, 3]       type: std::vector
     * v5 = ["1", "2", "3"] type: std::vector
     */

    std::cout << "v1 = " << v1 << ", which is type: " << bc::demangle(typeid(v1).name()) << std::endl;
    std::cout << "v2 = " << v2 << ", which is type: " << bc::demangle(typeid(v2).name()) << std::endl;
    std::cout << "v3 = " << v3 << ", which is type: " << bc::demangle(typeid(v3).name()) << std::endl;
    std::cout << "v4 = "; for (auto& v : v4) std::cout << v << " "; std::cout << ", which is type: " << bc::demangle(typeid(v4).name()) << std::endl;
    std::cout << "v5 = "; for (auto& v : v5) std::cout << v << " "; std::cout << ", which is type: " << bc::demangle(typeid(v5).name()) << std::endl;

    // section exist, key not exist
    r.InsertEntry("section1", "my_custom_key", "hello world");

    // section&key not exist
    r.InsertEntry("new_section", "key1", 5);

    // Dump ini to file
    INIWriter::write("output.ini", r);

    return 0;
}

3.使用inipp.h头文件

3.1 解析算法

section被设置为空字符串

从文件中读取每一行并从空白处修剪。

• 如果行为空或以;开始然后什么都没发生。
• 否则，如果行以 [ 开头，则section将更改为 [ 和 ] 之间的字符串。如果行不以 ] 结尾，则报告错误。
• 否则，如果行包含 = 符号，则 = 之前的所有字符都被视为变量， = 之后的所有字符都被视为值。两者都被修剪。如果变量之前已经赋值，则会报告错误。否则，将相应的赋值添加到该section。
• 否则，该行被报告为错误。

3.2 默认section算法

将默认section中的每个变量插入到其他每个section中，而不覆盖现有变量。

3.3 Interpolation算法

1.每个section内部，遇到的每个variable都被{section:variable}代替

2.每个{section:variable}都被它的值代替

3.重复上一步，直到无法再进行替换，或者直到达到递归深度（默认为 10）。

3.4 代码实现

1.inipp.h

/*
MIT License
Copyright (c) 2017-2020 Matthias C. M. Troffaes
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

#pragma once

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

2.example.ini

3.example.cpp

#include 
#include "inipp.h"

int main() {
	inipp::Ini ini;
	std::ifstream is("example.ini");
	ini.parse(is);
	std::cout << "raw ini file:" << std::endl;
	ini.generate(std::cout);
	ini.default_section(ini.sections["DEFAULT"]);
	ini.interpolate();
	std::cout << "ini file after default section and interpolation:" << std::endl;
	ini.generate(std::cout);
	int compression_level = -1;
	inipp::get_value(ini.sections["bitbucket.org"], "CompressionLevel", compression_level);
	std::cout << "bitbucket.org compression level: " << compression_level << std::endl;
	return 0;
}

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