C实现简单的xml格式文件

今天在工作中遇到了一个需要处理xml格式的字符串，需求是修改某个固定的value值，并且还要把这个xml的key和value按照原本的格式在推送回去。

如果使用库，就显得太臃肿了，就想写个简单的demo实现这个功能：

/*

AnalysisXml.c

*/

#include<stdio.h>

#include<string.h>

/* function: find  the corresponding value with the key transmitted

*   parameter :

*   [in/out] pTmpXml  the afferent string of xml that remaining after finding

*   [int]pKey  the key of incoming

*   [out]pValue  find the corresponding value

*   returned value:

*   -1 :  pStrXml or pStuXml is null

*   -2 :  the corresponding value is null or the key is not find

*/

static int AnalysisXml(char *pTmpXml, char *pValue, char *pKey)

{

    int iRet = -;

    if (pTmpXml == NULL || pValue == NULL || pKey == NULL)

    {

        return iRet;

    }

    memset(pValue, , sizeof(pValue));

    char BegKey[] = {};

    char EndKey[] = {};

    sprintf(BegKey, "<%s>", pKey);

    sprintf(EndKey, "</%s>", pKey);

    //printf("BegKey = %s\n", BegKey);

    //printf("EndKey = %s\n", EndKey);

    char *pBegin = pTmpXml;

    char *pEnd = NULL;

    int BegKey_len = strlen(BegKey);

    if ( (pBegin = strstr(pTmpXml, BegKey)) != NULL)

    {

        pEnd = strstr(pBegin + ,EndKey );

        memcpy(pValue, pBegin + BegKey_len, pEnd - pBegin - BegKey_len);

        //printf("%s = %s\n", BegKey, pValue);

        pTmpXml = pEnd + strlen(EndKey);

        //printf("pTmpXml = %s\n",pTmpXml);

        iRet = ;

    }

    else

    {

        iRet = -;

    }

    return iRet;

}

/* function: analysis string whose foramt is xml

*   parameter :

*   [in] pStrXml  the afferent string of xml

*   [out]pStuXml  the struct of saving  value of various

*   returned value:

*   -1 :  pStrXml or pStuXml is null

*/

int HandleXml(char *pStrXml, XML_CONFIG_INPUT *pStuXml)

{

    int iRet = -;

    if (pStrXml == NULL || pStuXml == NULL)

    {

        return iRet;  //

    }

    char szInbuf[] = {};

    int nInbufSize = ;

    nInbufSize += sprintf(szInbuf, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>");

    char key[] = {};

    char value[] = {};

    char *pTmpXml = pStrXml;

    char KeyXml[][] = {"id", "maxFrameRate", "reflectiveEnable", "reflectiveTemperature",

                          "emissivity", "distance", "refreshInterval", "distanceUnit",

                           "temperatureDataLength", "jpegPicEnabled"};

    int len_KeyXml = sizeof(KeyXml) / sizeof(KeyXml[]);

    printf("len_KeyXml = %d\n", len_KeyXml);

    for (int i =  ; i < len_KeyXml; i++)

    {

        //printf("KeyXml[%d] = %s\n", i, KeyXml[i]);

        sprintf(key, "%s", KeyXml[i]);

        iRet = AnalysisXml(pTmpXml, value, key);

        if (value != NULL)

        {

            printf("%s = %s\n", key, value);

            bool flag = (strcmp(key, "jpegPicEnabled"));

            if(!flag)

            {

                nInbufSize += sprintf(szInbuf+nInbufSize, "\n<JpegPictureWithAppendData>");

            }

            nInbufSize += sprintf(szInbuf+nInbufSize, "\n<%s>%s</%s>", key, value, key);

            if(!flag)

            {

                nInbufSize += sprintf(szInbuf+nInbufSize, "\n</JpegPictureWithAppendData>");

            }

        }

        else

        {

            printf("value is null\n");

        }

    }

    printf("\nszInbuf = %s \n",szInbuf);

    return ;

}

int main()

{

    int iRet = -;

    char Outxml[] = " <?xml version=\"1.0\" encoding=\"UTF-8\"?> \n\

<PixelToPixelParam version=\"2.0\" xmlns=\"http://www.hikvision.com/ver20/XMLSchema\"> \n\

<id></id>  \n\

<maxFrameRate></maxFrameRate>    \n\

<reflectiveEnable>false</reflectiveEnable>  \n\

<reflectiveTemperature>20.00</reflectiveTemperature>\n\

<emissivity>0.96</emissivity>\n\

<distance></distance>\n\

<refreshInterval></refreshInterval>\n\

<distanceUnit>centimeter</distanceUnit>\n\

<temperatureDataLength></temperatureDataLength>\n\

<JpegPictureWithAppendData>\n\

<jpegPicEnabled>true</jpegPicEnabled>\n\

</JpegPictureWithAppendData>\n\

</PixelToPixelParam>";

    char Inxml[] = {};

    float fEmissvity = 0.01;

    int wDistance = ;

    //iRet = HandleXml(Outxml, &stuXml);

    char szInbuf[] = {};

    int nInbufSize = ;

    nInbufSize += sprintf(szInbuf, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>");

    char key[] = {};

    char value[] = {};

    char *pTmpXml = Outxml;

    char KeyXml[][] = {"id", "maxFrameRate", "reflectiveEnable", "reflectiveTemperature",

                          "emissivity", "distance", "refreshInterval", "distanceUnit",

                           "temperatureDataLength", "jpegPicEnabled"};

    int len_KeyXml = sizeof(KeyXml) / sizeof(KeyXml[]);

    printf("len_KeyXml = %d\n", len_KeyXml);

    for (int i =  ; i < len_KeyXml; i++)

    {

        //printf("KeyXml[%d] = %s\n", i, KeyXml[i]);

        sprintf(key, "%s", KeyXml[i]);

        iRet = AnalysisXml(pTmpXml, value, key);

        if (value != NULL)

        {

            printf("%s = %s\n", key, value);

            bool flag = (strcmp(key, "jpegPicEnabled"));

            if(!flag)

            {

                nInbufSize += sprintf(szInbuf+nInbufSize, "\n<JpegPictureWithAppendData>");

            }

            if (  == (strcmp(key, "emissivity")))

            {

                nInbufSize += sprintf(szInbuf+nInbufSize, "\n<%s>%.2f</%s>", key, fEmissvity, key);

            }

            else if (  == (strcmp(key, "distance")))

            {

                nInbufSize += sprintf(szInbuf+nInbufSize, "\n<%s>%d</%s>", key, wDistance, key);

            }

            else

            {

                nInbufSize += sprintf(szInbuf+nInbufSize, "\n<%s>%s</%s>", key, value, key);

            }

            if(!flag)

            {

                nInbufSize += sprintf(szInbuf+nInbufSize, "\n</JpegPictureWithAppendData>");

            }

        }

        else

        {

            printf("value is null\n");

        }

    }

    printf("\nszInbuf = %s \n",szInbuf);

    return ;

}

如果是都xml文件的话只需要加上读写文件操作就可以使用了。

这个是非常简单的xml文件解析

其实还需要一个错误控制，对于遇到的每一个错误都有相应的返回码，在读取文件错误的时候可以准确的定位到错误在哪里发生的。

巴特西

C实现简单的xml格式文件

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