stl下string 一些类似MFC中CString的函数
2017-08-15 19:54
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class cstr
{
public:
static void to_lower(char *str)
{
int i = 0;
while(str[i] != '\0')
{
if((str[i] >= 'A') && (str[i] <= 'Z'))
{
str[i] += 32;
}
++i;
}
}
static void to_upper(char *str)
{
int i = 0;
while(str[i] != '\0')
{
if((str[i] >= 'a') && (str[i] <= 'z'))
{
str[i] -= 32;
}
++i;
}
}
static void to_upper(std::string& str)
{
for (std::string::iterator it=str.begin(); it!=str.end(); ++it)
{
if((*it >= 'a') && (*it <= 'z'))
{
*it -= 32;
}
}
}
static void to_lower(std::string& str)
{
for (std::string::iterator it=str.begin(); it!=str.end(); ++it)
{
if((*it >= 'A') && (*it <= 'Z'))
{
*it += 32;
}
}
}
/*
static std::string to_upper(char *str)
{
int i = 0;
while(str[i] != '\0')
{
if((str[i] >= 'a') && (str[i] <= 'z'))
{
str[i] -= 32;
}
++i;
}
return str;
}
*/
//字符串格式化函数
static std::string format(const char *fmt, ...)
{
if (NULL == fmt)
{
return "";
}
std::string strResult = "";
va_list marker = NULL;
va_start(marker, fmt); //初始化变量参数
size_t nLength = 1024*8+1; //获取格式化字符串长度
std::vector<char> vBuffer(nLength, '\0'); //创建用于存储格式化字符串的字符数组
MARK:int nWritten = _vsnprintf(&vBuffer[0], vBuffer.size(), fmt, marker);
//当nwritten不小于0时返回的格式化到vbuffer中的数据长度,当小于0时说明出错,等于-1时说明长度不够,此时将重新分配空间,然后再做格式化
if (nWritten >= 0)
{
strResult = &vBuffer[0];
}
//vbuffer长度不够,扩展nlength/2的长度
else if (-1 == nWritten)
{
vBuffer.erase(vBuffer.begin(), vBuffer.end());
nLength += nLength;
vBuffer.resize(nLength, '\0');
//最多分配1G的空间,超过1G将不再处理
if (nLength < 1024*1024*1024)
{
goto MARK;
}
}
va_end(marker); //重置变量参数
return strResult;
}
//字符串格式化函数
static std::string format_s(size_t maxsize, const char *fmt, ...)
{
if (NULL == fmt)
{
return "";
}
std::string strResult = "";
va_list marker = NULL;
va_start(marker, fmt); //初始化变量参数
size_t nLength = maxsize+1; //获取格式化字符串长度
std::vector<char> vBuffer(nLength, '\0'); //创建用于存储格式化字符串的字符数组
int nWritten = _vsnprintf(&vBuffer[0], vBuffer.size(), fmt, marker);
//当nwritten不小于0时返回的格式化到vbuffer中的数据长度,当小于0时说明出错,此时返回空字符串
if (nWritten > 0)
{
strResult = &vBuffer[0];
}
va_end(marker); //重置变量参数
return strResult;
}
static std::string left(const std::string& str, int nCount)
{
std::string s = str;
int nSize = s.size();
nCount<0?nCount=0:nCount;
nCount>nSize?nCount=nSize:nCount;
if (0 == nCount && 0 == nSize)
{
s = "";
}
else
{
s.erase(MIN2(nCount, nSize), nSize);
}
return s;
}
static std::string right(const std::string& str, int nCount)
{
std::string s = str;
nCount<0?nCount=0:nCount;
int nSize = s.size();
int nLen = nSize-nCount;
if (nLen > 0)
{
s.erase(0, nLen);
}
return s;
}
static void replace(std::string& str, const char* szOld, const char* szNew)
{
if (NULL != szNew && NULL != szOld)
{
int nOldLen = strlen(szOld);
int nNewLen = strlen(szNew);
bool bEqual = ((nNewLen == nOldLen) && 0 == memcmp(szOld, szNew, nOldLen));
//szOld不为空字符串且szOld和szNew不相同
if (nOldLen > 0 && !bEqual)
{
size_t found = str.find(szOld);
while (found != std::string::npos)
{
str.replace(found, nOldLen, szNew);
found += nNewLen;
found = str.find(szOld, found);
}
}
}
}
//去右空格
static void trimright(std::string& str, const char* szTargets=NULL)
{
int nLen = str.size();
int nTargetsLen = 0;
//默认只去空格
if (NULL == szTargets || (0 == strlen(szTargets)))
{
if (nLen > 0)
{
while (nLen > 0)
{
if (str[nLen - 1] != 32)
{
break;
}
else
{
--nLen;
str.erase(nLen, 1);
}
}
}
}
else
{
nTargetsLen = strlen(szTargets);
if (nLen > 0)
{
int i = 0;
while (nLen > 0)
{
if (str[nLen - 1] != szTargets[nTargetsLen - i - 1])
{
break;
}
else
{
++i;
--nLen;
}
if (i == nTargetsLen)
{
str.erase(nLen, nTargetsLen);
i = 0;
nLen = str.size();
}
}
}
}
}
//去左空格
static void trimleft(std::string& str, const char* szTargets=NULL)
{
if (!szTargets || '\0'==szTargets[0] || '\0'==szTargets[1])
{
const char ch = (!szTargets || '\0'==szTargets[0])?' ':szTargets[0];
std::string::iterator it;
for (it=str.begin(); it!=str.end(); ++it)
{
if (ch != *it)
break;
}
if (it != str.begin())
{
str.erase(str.begin(), it);
}
}
else
{
const size_t nLen = strlen(szTargets);
const size_t nStrLen = str.size();
size_t nPos = 0;
while ((nPos + nLen) <= nStrLen)
{
if (0 != memcmp(str.data()+nPos, szTargets, nLen))
{
break;
}
nPos += nLen;
}
if (nPos > 0)
{
str.erase(0, nPos);
}
}
}
};
{
public:
static void to_lower(char *str)
{
int i = 0;
while(str[i] != '\0')
{
if((str[i] >= 'A') && (str[i] <= 'Z'))
{
str[i] += 32;
}
++i;
}
}
static void to_upper(char *str)
{
int i = 0;
while(str[i] != '\0')
{
if((str[i] >= 'a') && (str[i] <= 'z'))
{
str[i] -= 32;
}
++i;
}
}
static void to_upper(std::string& str)
{
for (std::string::iterator it=str.begin(); it!=str.end(); ++it)
{
if((*it >= 'a') && (*it <= 'z'))
{
*it -= 32;
}
}
}
static void to_lower(std::string& str)
{
for (std::string::iterator it=str.begin(); it!=str.end(); ++it)
{
if((*it >= 'A') && (*it <= 'Z'))
{
*it += 32;
}
}
}
/*
static std::string to_upper(char *str)
{
int i = 0;
while(str[i] != '\0')
{
if((str[i] >= 'a') && (str[i] <= 'z'))
{
str[i] -= 32;
}
++i;
}
return str;
}
*/
//字符串格式化函数
static std::string format(const char *fmt, ...)
{
if (NULL == fmt)
{
return "";
}
std::string strResult = "";
va_list marker = NULL;
va_start(marker, fmt); //初始化变量参数
size_t nLength = 1024*8+1; //获取格式化字符串长度
std::vector<char> vBuffer(nLength, '\0'); //创建用于存储格式化字符串的字符数组
MARK:int nWritten = _vsnprintf(&vBuffer[0], vBuffer.size(), fmt, marker);
//当nwritten不小于0时返回的格式化到vbuffer中的数据长度,当小于0时说明出错,等于-1时说明长度不够,此时将重新分配空间,然后再做格式化
if (nWritten >= 0)
{
strResult = &vBuffer[0];
}
//vbuffer长度不够,扩展nlength/2的长度
else if (-1 == nWritten)
{
vBuffer.erase(vBuffer.begin(), vBuffer.end());
nLength += nLength;
vBuffer.resize(nLength, '\0');
//最多分配1G的空间,超过1G将不再处理
if (nLength < 1024*1024*1024)
{
goto MARK;
}
}
va_end(marker); //重置变量参数
return strResult;
}
//字符串格式化函数
static std::string format_s(size_t maxsize, const char *fmt, ...)
{
if (NULL == fmt)
{
return "";
}
std::string strResult = "";
va_list marker = NULL;
va_start(marker, fmt); //初始化变量参数
size_t nLength = maxsize+1; //获取格式化字符串长度
std::vector<char> vBuffer(nLength, '\0'); //创建用于存储格式化字符串的字符数组
int nWritten = _vsnprintf(&vBuffer[0], vBuffer.size(), fmt, marker);
//当nwritten不小于0时返回的格式化到vbuffer中的数据长度,当小于0时说明出错,此时返回空字符串
if (nWritten > 0)
{
strResult = &vBuffer[0];
}
va_end(marker); //重置变量参数
return strResult;
}
static std::string left(const std::string& str, int nCount)
{
std::string s = str;
int nSize = s.size();
nCount<0?nCount=0:nCount;
nCount>nSize?nCount=nSize:nCount;
if (0 == nCount && 0 == nSize)
{
s = "";
}
else
{
s.erase(MIN2(nCount, nSize), nSize);
}
return s;
}
static std::string right(const std::string& str, int nCount)
{
std::string s = str;
nCount<0?nCount=0:nCount;
int nSize = s.size();
int nLen = nSize-nCount;
if (nLen > 0)
{
s.erase(0, nLen);
}
return s;
}
static void replace(std::string& str, const char* szOld, const char* szNew)
{
if (NULL != szNew && NULL != szOld)
{
int nOldLen = strlen(szOld);
int nNewLen = strlen(szNew);
bool bEqual = ((nNewLen == nOldLen) && 0 == memcmp(szOld, szNew, nOldLen));
//szOld不为空字符串且szOld和szNew不相同
if (nOldLen > 0 && !bEqual)
{
size_t found = str.find(szOld);
while (found != std::string::npos)
{
str.replace(found, nOldLen, szNew);
found += nNewLen;
found = str.find(szOld, found);
}
}
}
}
//去右空格
static void trimright(std::string& str, const char* szTargets=NULL)
{
int nLen = str.size();
int nTargetsLen = 0;
//默认只去空格
if (NULL == szTargets || (0 == strlen(szTargets)))
{
if (nLen > 0)
{
while (nLen > 0)
{
if (str[nLen - 1] != 32)
{
break;
}
else
{
--nLen;
str.erase(nLen, 1);
}
}
}
}
else
{
nTargetsLen = strlen(szTargets);
if (nLen > 0)
{
int i = 0;
while (nLen > 0)
{
if (str[nLen - 1] != szTargets[nTargetsLen - i - 1])
{
break;
}
else
{
++i;
--nLen;
}
if (i == nTargetsLen)
{
str.erase(nLen, nTargetsLen);
i = 0;
nLen = str.size();
}
}
}
}
}
//去左空格
static void trimleft(std::string& str, const char* szTargets=NULL)
{
if (!szTargets || '\0'==szTargets[0] || '\0'==szTargets[1])
{
const char ch = (!szTargets || '\0'==szTargets[0])?' ':szTargets[0];
std::string::iterator it;
for (it=str.begin(); it!=str.end(); ++it)
{
if (ch != *it)
break;
}
if (it != str.begin())
{
str.erase(str.begin(), it);
}
}
else
{
const size_t nLen = strlen(szTargets);
const size_t nStrLen = str.size();
size_t nPos = 0;
while ((nPos + nLen) <= nStrLen)
{
if (0 != memcmp(str.data()+nPos, szTargets, nLen))
{
break;
}
nPos += nLen;
}
if (nPos > 0)
{
str.erase(0, nPos);
}
}
}
};
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