C++ 配置文件类的封装

有时开发项目，需要对数据库等配置放到程序对外面作为配置文件，配置文件对读取

ConfigManager.h

/*
 * ConfigManager.h
 *
 *  Created on: 2018年7月28日
 *      Author: oftenlin
 */

#ifndef CONFIGMANAGER_H_
#define CONFIGMANAGER_H_
#define SIZE_FILENAME 50

class ConfigManager{
public:
    ConfigManager(const char *filename){ConfigFileLoad(filename);};
    ~ConfigManager(){ConfigFileFree();};
    //加载ini文件至内存

    char gFilename[SIZE_FILENAME];
    char *gBuffer;
    int gBuflen;
    int ConfigFileLoad(const char *filename);
    //释放ini文件所占资源
    void ConfigFileFree();
    int FindSection(const char *section, char **sect1, char **sect2, char **cont1, char **cont2, char **nextsect);
    //获取字符串，不带引号
    int GetString(const char *section, const char *key, char *value, int size, const char *defvalue);
    //获取整数值
    int GetInt(const char *section, const char *key, int defvalue);
    //获取浮点数
    double GetDouble(const char *section, const char *key, double defvalue);
    int GetValue(const char *section, const char *key, char *value, int maxlen, const char *defvalue);
    //设置字符串：若value为NULL，则删除该key所在行，包括注释
    int SetString(const char *section, const char *key, const char *value);
    //设置整数值：base取值10、16、8，分别表示10、16、8进制，缺省为10进制
    int SetInt(const char *section, const char *key, int value, int base=);
//    int iniGetIP(const char *section, const char *key, BasicHashTable *hashtable, int size, const char *defvalue);
};

#endif /* CONFIGMANAGER_H_ */

ConfigManager.cpp

/*
 * ConfigManager.cpp
 * Created on: 2018年7月28日
 * Author: oftenlin
 */

#include <ctype.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "ConfigManager.h"

#define  SIZE_LINE  100

#define fmin(x, y)      (x <= y) ? x : y

typedef enum _ELineType_ {
    LINE_IDLE,      //未处理行
    LINE_ERROR,     //错误行
    LINE_EMPTY,     //空白行或注释行
    LINE_SECTION,   //节定义行
    LINE_VALUE      //值定义行
} ELineType ;

//去除串首尾空格，原串被改写
 char *StrStrip(char *s)
{
    size_t size;
    char *p1, *p2;

    size = strlen(s);
    if (!size)
        return s;

    p2 = s + size - ;

    while ((p2 >= s) && isspace(*p2))
        p2 --;
    *(p2 + ) = '\0';

    p1 = s;
    while (*p1 && isspace(*p1))
        p1 ++;
    if (s != p1)
        memmove(s, p1, p2 - p1 + );
    return s;
}

//不区分大小写比较字符串
 int StriCmp(const char *s1, const char *s2)
{
    int ch1, ch2;
    do
    {
        ch1 = (unsigned char)*(s1++);
        if ((ch1 >= 'A') && (ch1 <= 'Z'))
            ch1 += 0x20;

        ch2 = (unsigned char)*(s2++);
        if ((ch2 >= 'A') && (ch2 <= 'Z'))
            ch2 += 0x20;
    } while ( ch1 && (ch1 == ch2) );
    return(ch1 - ch2);
}

//取一行
//输入：数据区(指针及长度)
//输出：行类型、有效内容串(去首尾空格)、注释首、注释尾、下一行首(行尾与下一行首间为换行符)
//      有效内容位置为[buf, rem1)
 int GetLine(char *buf, int buflen, char *content, char **rem1, char **rem2, char **nextline)
{
    char *cont1, *cont2;
    int cntblank, cntCR, cntLF;     //连续空格、换行符数量
    char isQuot1, isQuot2;          //引号
    int i;
    char *p;

    //首先断行断注释，支持如下换行符：\r、\n、\r\n、\n\r
    cntblank = ;
    cntCR = cntLF = ;
    isQuot1 = isQuot2 = ;
    cont1 = *rem1 = ;
    content[] = ;
    for (i = , p = buf; i < buflen; i ++, p ++)
    {
        if (*p == ) {
            p ++;
            break;
        }
        //2个CR或LF，行结束
        if (cntCR ==  || cntLF == ) {
            p --;   //回溯1
            break;
        }
        //CR或LF各1个之后任意字符，行结束
        if (cntCR + cntLF >= ) {
            break;
        }
        //CR或LF之后出现其它字符，行结束
        if ((cntCR || cntLF) && *p != '\r' && *p != '\n')
            break;

        switch (*p) {
        case '\r':
            cntCR ++;
            break;
        case '\n':
            cntLF ++;
            break;
        case '\'':
            if (!isQuot2)
                isQuot1 =  - isQuot1;
            break;
        case '\"':
            if (!isQuot1)
                isQuot2 =  - isQuot2;
            break;
        case ';':
        case '#':
            if (isQuot1 || isQuot2)
                break;
            if (*rem1 == NULL)
                *rem1 = p - cntblank;
            break;
        default:
            if (isspace((unsigned char)*p)) {
                cntblank ++;
            } else {
                cntblank = ;
                if ((*rem1 == NULL) && (cont1 == NULL))
                    cont1 = p;
            }
            break;
        }
    }

    *nextline = p;
    *rem2 = p - cntCR - cntLF;
    if (*rem1 == NULL)
        *rem1 = *rem2;
    cont2 = *rem1 - cntblank;

    if (cont1 == NULL) {
        cont1 = cont2;
        return LINE_EMPTY;
    }

    i = (int)(cont2 - cont1);
    if (i >= SIZE_LINE)
        return LINE_ERROR;

    //内容头尾已无空格
    memcpy(content, cont1, i);
    content[i] = ;

    if (content[] == '[' && content[i - ] == ']')
        return LINE_SECTION;
    if (strchr(content, '=') != NULL)
        return LINE_VALUE;

    return LINE_ERROR;
}

//取一节section
//输入：节名称
//输出：成功与否、节名称首、节名称尾、节内容首、节内容尾(含换行)、下一节首(节尾与下一节首间为空行或注释行)
 int ConfigManager::FindSection(const char *section, char **sect1, char **sect2, char **cont1, char **cont2, char **nextsect)
{
    int type;
    char content[SIZE_LINE];
    char *rem1, *rem2, *nextline;

    char *p;
    char *empty;
    int uselen = ;
    char found = ;

    if (gBuffer == NULL) {
        return ;
    }

    while (gBuflen - uselen > ) {
        p = gBuffer + uselen;
        type = GetLine(p, gBuflen - uselen, content, &rem1, &rem2, &nextline);
        uselen += (int)(nextline - p);

        if (LINE_SECTION == type) {
            if (found || section == NULL) break;        //发现另一section
            content[strlen(content) - ] = ;           //去尾部]
            StrStrip(content + );                      //去首尾空格
            if (StriCmp(content + , section) == ) {
                found = ;
                *sect1 = p;
                *sect2 = rem1;
                *cont1 = nextline;
            }
            empty = nextline;
        } else
        if (LINE_VALUE == type) {
            if (!found && section == NULL) {
                found = ;
                *sect1 = p;
                *sect2 = p;
                *cont1 = p;
            }
            empty = nextline;
        }
    }

    if (!found) return ;

    *cont2 = empty;
    *nextsect = nextline;
    return ;
}

//从一行取键、值
//输入：内容串(将被改写)
//输出：键串、值串
 void GetKeyValue(char *content, char **key, char **value)
{
    char *p;

    p = strchr(content, '=');
    *p = ;
    StrStrip(content);
    StrStrip(p + );
    *key = content;
    *value = p + ;
}

//释放ini文件所占资源
void ConfigManager:: ConfigFileFree()
{
    if (gBuffer != NULL) {
        free(gBuffer);
        gBuffer = ;
        gBuflen = ;
    }
}

//加载ini文件至内存
int ConfigManager::ConfigFileLoad(const char *filename)
{
    FILE *file;
    int len;

    //iniFileFree();
    if (strlen(filename) >= sizeof(gFilename))
        return ;
    strcpy(gFilename, filename);

    file = fopen(gFilename, "ab+");
    if (file == NULL)
        return ;

    fseek(file, , SEEK_END);
    len = ftell(file);
    gBuffer =(char *) malloc(len);
    if (gBuffer == NULL) {
        fclose(file);
        return ;
    }

    fseek(file, , SEEK_SET);
    len = fread(gBuffer, , len, file);
    fclose(file);
    gBuflen = len;
    return ;
}

//读取值原始串
 int ConfigManager::GetValue(const char *section, const char *key, char *value, int maxlen, const char *defvalue)
{
    int type;
    char content[SIZE_LINE];
    char *rem1, *rem2, *nextline;
    char *key0, *value0;

    char *p;
    int uselen = ;
    char found = ;
    int len;

    if (gBuffer == NULL || key == NULL) {
        if (value != NULL)
            value[] = ;
        return ;
    }

    while (gBuflen - uselen > ) {
        p = gBuffer + uselen;
        type = GetLine(p, gBuflen - uselen, content, &rem1, &rem2, &nextline);
        uselen += (int)(nextline - p);

        if (LINE_SECTION == type) {
            if (found || section == NULL) break;        //发现另一section
            content[strlen(content) - ] = ;           //去尾部]
            StrStrip(content + );                      //去首尾空格
            if (StriCmp(content + , section) == ) {
                found = ;
            }
        } else
        if (LINE_VALUE == type) {
            if (!found && section == NULL) {
                found = ;
            }
            if (!found)
                continue;
            GetKeyValue(content, &key0, &value0);
            if (StriCmp(key0, key) == ) {
                len = strlen(value0);
                if (len == ) break;        //空值视为无效
                if (value != NULL) {
                    len = fmin(len, maxlen - );
                    strncpy(value, value0, len);
                    value[len] = ;
                }
            //  printf("value = %s\n",value);
                return ;
            }
        }
    }

    //未发现键值取缺省
    if (value != NULL) {
        if (defvalue != NULL) {
            len = fmin(strlen(defvalue), maxlen - );
            strncpy(value, defvalue, len);
            value[len] = ;
            SetString(section, key, defvalue);
        } else {
            value[] = ;
        }
    }
    return ;
}

//获取字符串，不带引号
int ConfigManager::GetString(const char *section, const char *key, char *value, int maxlen, const char *defvalue)
{
    int ret;
    int len;

    ret = GetValue(section, key, value, maxlen, defvalue);
    if (!ret)
        return ret;

    //去首尾空格
    len = strlen(value);
    if (value[] == '\'' && value[len - ] == '\'') {
        value[len - ] = ;
        memmove(value, value + , len - );
    } else
    if (value[] == '\"' && value[len - ] == '\"') {
        value[len - ] = ;
        memmove(value, value + , len - );
    }
    return ret;
}

//获取整数值
int ConfigManager::GetInt(const char *section, const char *key, int defvalue)
{
    char valstr[];

    if (GetValue(section, key, valstr, sizeof(valstr), NULL))
        return (int)strtol(valstr, NULL, );
    SetInt(section, key,defvalue,);
    return defvalue;
}

//获取浮点数
double ConfigManager::GetDouble(const char *section, const char *key, double defvalue)
{
    char valstr[];

    if (GetValue(section, key, valstr, sizeof(valstr), NULL))
        return (int)atof(valstr);
    return defvalue;
}

//设置字符串：若value为NULL，则删除该key所在行，包括注释
int ConfigManager::SetString(const char *section, const char *key, const char *value)
{
    FILE *file;
    char *sect1, *sect2, *cont1, *cont2, *nextsect;
    char *p;
    int len, type;
    char content[SIZE_LINE];
    char *key0, *value0;
    char *rem1, *rem2, *nextline;

    if (gBuffer == NULL) {
        return ;
    }

    if (FindSection(section, &sect1, &sect2, &cont1, &cont2, &nextsect) == )
    {
        //未找到节
        //value无效则返回
        if (value == NULL)
            return ;
        //在文件尾部添加
        file = fopen(gFilename, "ab");
        if (file == NULL)
            return ;
        fprintf(file, "\r\n[%s]\r\n%s=%s;\r\n", section, key, value);
        fclose(file);
        ConfigFileLoad(gFilename);
        return ;
    }

    //找到节，则节内查找key
    p = cont1;
    len = (int)(cont2 - cont1);
    while (len > ) {
        type = GetLine(p, len, content, &rem1, &rem2, &nextline);
        if (LINE_VALUE == type) {
            GetKeyValue(content, &key0, &value0);
            if (StriCmp(key0, key) == ) {
                //找到key
                file = fopen(gFilename, "wb");
                if (file == NULL)
                    return ;
                len = (int)(p - gBuffer);
                fwrite(gBuffer, , len, file);                  //写入key之前部分
                if (value == NULL) {
                    //value无效，删除
                    len = (int)(nextline - gBuffer);            //整行连同注释一并删除
                } else {
                    //value有效，改写
                    fprintf(file, "%s=%s", key, value);
                    len = (int)(rem1 - gBuffer);                //保留尾部原注释!
                }
                fwrite(gBuffer + len, , gBuflen - len, file);  //写入key所在行含注释之后部分
                fclose(file);
                ConfigFileLoad(gFilename);
                return ;
            }
        }

        len -= (int)(nextline - p);
        p = nextline;
    }

    //未找到key

    //value无效则返回
    if (value == NULL)
        return ;

    //在文件尾部添加
    file = fopen(gFilename, "wb");
    if (file == NULL)
        return ;
    len = (int)(cont2 - gBuffer);
    fwrite(gBuffer, , len, file);                  //写入key之前部分
    fprintf(file, "%s=%s;\r\n", key, value);
    fwrite(gBuffer + len, , gBuflen - len, file);  //写入key之后部分
    fclose(file);
    ConfigFileLoad(gFilename);
    return ;
}

//设置整数值：base取值10、16、8，分别表示10、16、8进制，缺省为10进制
int ConfigManager::SetInt(const char *section, const char *key, int value, int base)
{
    char valstr[];

    switch (base) {
    case :
        sprintf(valstr, "0x%x", value);
        return SetString(section, key, valstr);
    case :
        sprintf(valstr, "0%o", value);
        return SetString(section, key, valstr);
    default:    //
        sprintf(valstr, "%d", value);
        return SetString(section, key, valstr);
    }
}

读取方法

#include "utils/ConfigManager.h"
int main() {
    ConfigManager *configManger=new
    ConfigManager("config.ini");
    char *general_sect="general";
    int city = configManger->GetInt(general_sect,"cityid" ,);
    //整型数字的获取
　　
}

配置文件

[general]
cityid=1;
dbhost=127.0.0.1;
port=3306;
user=root;
passwd=root;