什么是在C++中解析INI文件的最简单方法?

92

我正在尝试使用C++解析INI文件。有什么最佳实践来实现这一目标吗?我应该使用Windows API提供的INI文件处理工具(我对此完全不熟悉),选择开源解决方案还是尝试手动解析呢?

13个回答

2

我知道这个问题很老,但是因为我需要一个适用于Linux、Win32等跨平台的东西,所以我遇到了它。我写了下面的函数,它是一个单独的函数,可以解析INI文件,希望其他人也能发现它的用处。

规则和注意事项: 要解析的缓冲区必须是以NULL结尾的字符串。将你的INI文件加载到char数组字符串中,并调用此函数进行解析。 节名称必须用[]括起来,例如[MySection],同时值和节必须在没有前导空格的行上开始。它可以解析带有Windows \r\n或Linux \n行结束符的文件。注释应该使用#或//并从文件顶部开始,不应该将注释与INI条目数据混合。返回的字符串两端的引号和撇号被修剪掉。只有当空格在引号外部时才会修剪空格。如果没有引号,则字符串不需要引号,并且去除空格。你还可以提取数字或其他数据,例如如果你有一个浮点数,只需对ret缓冲区执行atof(ret)。

//  -----note: no escape is nessesary for inner quotes or ticks-----
//  -----------------------------example----------------------------
//  [Entry2]
//  Alignment   = 1
//  LightLvl=128
//  Library     = 5555
//  StrValA =  Inner "quoted" or 'quoted' strings are ok to use
//  StrValB =  "This a "quoted" or 'quoted' String Value"
//  StrValC =  'This a "tick" or 'tick' String Value'
//  StrValD =  "Missing quote at end will still work
//  StrValE =  This is another "quote" example
//  StrValF =  "  Spaces inside the quote are preserved "
//  StrValG =  This works too and spaces are trimmed away
//  StrValH =
//  ----------------------------------------------------------------
//12oClocker super lean and mean INI file parser (with section support)
//set section to 0 to disable section support
//returns TRUE if we were able to extract a string into ret value
//NextSection is a char* pointer, will be set to zero if no next section is found
//will be set to pointer of next section if it was found.
//use it like this... char* NextSection = 0;  GrabIniValue(X,X,X,X,X,&NextSection);
//buf is data to parse, ret is the user supplied return buffer
BOOL GrabIniValue(char* buf, const char* section, const char* valname, char* ret, int retbuflen, char** NextSection)
{
    if(!buf){*ret=0; return FALSE;}

    char* s = buf; //search starts at "s" pointer
    char* e = 0;   //end of section pointer

    //find section
    if(section)
    {
        int L = strlen(section);
        SearchAgain1:
        s = strstr(s,section); if(!s){*ret=0; return FALSE;}    //find section
        if(s > buf && (*(s-1))!='\n'){s+=L; goto SearchAgain1;} //section must be at begining of a line!
        s+=L;                                                   //found section, skip past section name
        while(*s!='\n'){s++;} s++;                              //spin until next line, s is now begining of section data
        e = strstr(s,"\n[");                                    //find begining of next section or end of file
        if(e){*e=0;}                                            //if we found begining of next section, null the \n so we don't search past section
        if(NextSection)                                         //user passed in a NextSection pointer
        { if(e){*NextSection=(e+1);}else{*NextSection=0;} }     //set pointer to next section
    }

    //restore char at end of section, ret=empty_string, return FALSE
    #define RESTORE_E     if(e){*e='\n';}
    #define SAFE_RETURN   RESTORE_E;  (*ret)=0;  return FALSE

    //find valname
    int L = strlen(valname);
    SearchAgain2:
    s = strstr(s,valname); if(!s){SAFE_RETURN;}             //find valname
    if(s > buf && (*(s-1))!='\n'){s+=L; goto SearchAgain2;} //valname must be at begining of a line!
    s+=L;                                                   //found valname match, skip past it
    while(*s==' ' || *s == '\t'){s++;}                      //skip spaces and tabs
    if(!(*s)){SAFE_RETURN;}                                 //if NULL encounted do safe return
    if(*s != '='){goto SearchAgain2;}                       //no equal sign found after valname, search again
    s++;                                                    //skip past the equal sign
    while(*s==' '  || *s=='\t'){s++;}                       //skip spaces and tabs
    while(*s=='\"' || *s=='\''){s++;}                       //skip past quotes and ticks
    if(!(*s)){SAFE_RETURN;}                                 //if NULL encounted do safe return
    char* E = s;                                            //s is now the begining of the valname data
    while(*E!='\r' && *E!='\n' && *E!=0){E++;} E--;         //find end of line or end of string, then backup 1 char
    while(E > s && (*E==' ' || *E=='\t')){E--;}             //move backwards past spaces and tabs
    while(E > s && (*E=='\"' || *E=='\'')){E--;}            //move backwards past quotes and ticks
    L = E-s+1;                                              //length of string to extract NOT including NULL
    if(L<1 || L+1 > retbuflen){SAFE_RETURN;}                //empty string or buffer size too small
    strncpy(ret,s,L);                                       //copy the string
    ret[L]=0;                                               //null last char on return buffer
    RESTORE_E;
    return TRUE;

    #undef RESTORE_E
    #undef SAFE_RETURN
}

如何使用...示例...

char sFileData[] = "[MySection]\r\n"
"MyValue1 = 123\r\n"
"MyValue2 = 456\r\n"
"MyValue3 = 789\r\n"
"\r\n"
"[MySection]\r\n"
"MyValue1 = Hello1\r\n"
"MyValue2 = Hello2\r\n"
"MyValue3 = Hello3\r\n"
"\r\n";
char str[256];
char* sSec = sFileData;
char secName[] = "[MySection]"; //we support sections with same name
while(sSec)//while we have a valid sNextSec
{
    //print values of the sections
    char* next=0;//in case we dont have any sucessful grabs
    if(GrabIniValue(sSec,secName,"MyValue1",str,sizeof(str),&next)) { printf("MyValue1 = [%s]\n",str); }
    if(GrabIniValue(sSec,secName,"MyValue2",str,sizeof(str),0))     { printf("MyValue2 = [%s]\n",str); }
    if(GrabIniValue(sSec,secName,"MyValue3",str,sizeof(str),0))     { printf("MyValue3 = [%s]\n",str); }
    printf("\n");
    sSec = next; //parse next section, next will be null if no more sections to parse
}

2

除非您计划将应用程序制作成跨平台的,否则使用Windows API调用是最好的选择。只需忽略API文档中有关仅提供16位应用程序兼容性的注释即可。


1

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