简单解析SQL语句及遇到的小问题

#include <cstdio>
#include <iostream>
#include <cstring>
#include <cstdlib>

using namespace std;

class CFileUnit
{
    public:
        CFileUnit();
        ~CFileUnit();
        void GetFilePath(const char* psrFilePath);
        void OpenFile();
        bool isOpen();
        void GetSQLStatement(char* psrStmt);
        static void Erase(char* psrStmt);
        bool isEndFile();
    private:
        int m_iPos;
        FILE* m_pfFile;
        char m_srFilePath[128];
        bool m_bEndFile;
};

CFileUnit::CFileUnit()
{
    m_iPos = 0;
    m_pfFile = NULL;
    m_bEndFile = false;
    memset(m_srFilePath, 0, sizeof(m_srFilePath));
}

CFileUnit::~CFileUnit()
{
    if (!isOpen())
    {
        fclose(m_pfFile);
    }
}

bool CFileUnit::isEndFile()
{
    if (m_bEndFile)
    {
        return true;
    }
    return false;
}

bool CFileUnit::isOpen()
{
    if (m_pfFile != NULL)
    {
        return false;
    }
    else
    {
        return true;
    }
}

void CFileUnit::GetFilePath(const char* psrFilePath)
{
    if (NULL == psrFilePath)
    {
        return;
    }
    memset(m_srFilePath, 0, sizeof(m_srFilePath));
    strncpy(m_srFilePath, psrFilePath, sizeof(m_srFilePath));
}

void CFileUnit::OpenFile()
{
    m_pfFile = fopen(m_srFilePath, "r");
    if (NULL == m_pfFile)
    {
    }
}

void CFileUnit::GetSQLStatement(char* psrStmt)
{
    if (NULL == psrStmt)
    {
    }

    char chTmp = 0;
    char chPrev = 0;
    int iLen = 0;
    bool bInString = false;
    char srTmp[128] = {'\0'};

    while ((chTmp = fgetc(m_pfFile)) != EOF)
    {
        if ('\'' == chTmp)
        {
            if (chPrev != '\\')
            {
                if (!bInString)
                {
                    bInString = true;
                }
                else
                {
                    bInString = false;
                }
            }
        }
        else if (';' == chTmp && !bInString)
        {
            fseek(m_pfFile, m_iPos - iLen, SEEK_SET);
            memset(srTmp, 0, sizeof(srTmp));
            fread(srTmp, 1, iLen + 1, m_pfFile);
            strncpy(psrStmt, srTmp, sizeof(srTmp));
            CFileUnit::Erase(psrStmt);
            m_iPos++;
            return;
        }
        chPrev = chTmp;
        iLen++;
        m_iPos++;
    }
    m_bEndFile = true;
}

void CFileUnit::Erase(char* psrStmt)
{
    char* psrTra = psrStmt;
    char* psrSt = psrStmt;

    while (*psrTra != '\0')
    {
        if ('\n' == *psrTra || '\r' == *psrTra || ' ' == *psrTra)
        {
            psrTra++;
        }
        else
        {
            *psrSt++ = *psrTra++;
        }
    }
    *psrSt = '\0';
}

int main()
{
    char str[128] = {'\0'};
    CFileUnit fileUnit;

    fileUnit.GetFilePath("tempfile");
    fileUnit.OpenFile();

    while (1)
    {
        fileUnit.GetSQLStatement(str);
        if (fileUnit.isEndFile())
        {
            break;
        }
        cout << str << endl;
    }

    return 0;
}

tempfile文件内容：'\'name\''; ';\';;;'; update('\'\'');
缺陷：
遇到的问题：第90行和对应的113行。设置srTmp大小为1024字节，这样113执行时，覆盖了对象中其他属性的值，被改为0了，导致之后的函数调用出现“Segment error”。strncpy(psrStmt, srTmp, sizeof(srTmp));也应该改为strncpy(psrStmt, srTmp, sizeof(psrStmt));