[英]C++ Sanitize string function
I need to build my own sanitize function for the following chars: 我需要为以下字符构建自己的清理函数:
', ", \, \n, \r, \0 and CTRL-Z
I want to make sure that the following code will do the trick with no side effects: 我想确保以下代码可以完成没有副作用的技巧:
#include <iostream>
#include <string>
#include <memory>
#include <sstream>
#include <iomanip>
#include <algorithm>
void sanitize (std::string &stringValue)
{
stringValue.replace(stringValue.begin(), stringValue.end(), "\\", "\\\\");
stringValue.replace(stringValue.begin(), stringValue.end(), "'", "\\'");
stringValue.replace(stringValue.begin(), stringValue.end(), "\"", "\\\"");
stringValue.replace(stringValue.begin(), stringValue.end(), "\n", "");
stringValue.replace(stringValue.begin(), stringValue.end(), "\r", "");
stringValue.replace(stringValue.begin(), stringValue.end(), "\0", "");
stringValue.replace(stringValue.begin(), stringValue.end(), "\x1A", "");
}
int main()
{
std::string stringValue = "This is a test string with 'special //characters\n";
std::cout << stringValue << std::endl;
sanitize(stringValue);
std::cout << stringValue << std::endl;
}
This code is not working. 此代码无效。 Error: 错误:
terminate called after throwing an instance of 'std::length_error'
what(): basic_string::_M_replace
1
1 This is a test string with 'special //characters
See comment to my post as to why your replace
calls are incorrect. 请参阅我的帖子评论,为什么您的replace
呼叫不正确。 "\\0"
has another problem: "\\0"
还有另一个问题:
stringValue.replace(stringValue.begin(), stringValue.end(), "\0", "");
\\0
marks the end of a C string, so it will try to replace an empty string with an empty string. \\0
标记C字符串的结尾,因此它将尝试用空字符串替换空字符串。 It seems you are removing \\n, \\r, \\0 and CTRL-Z
, in which case you can use the erase-remove idiom instead for these: 看来你正在删除\\n, \\r, \\0 and CTRL-Z
,在这种情况下你可以使用erase-remove惯用法代替:
void sanitize(std::string &stringValue)
{
// Add backslashes.
for (auto i = stringValue.begin();;) {
auto const pos = std::find_if(
i, stringValue.end(),
[](char const c) { return '\\' == c || '\'' == c || '"' == c; }
);
if (pos == stringValue.end()) {
break;
}
i = std::next(stringValue.insert(pos, '\\'), 2);
}
// Removes others.
stringValue.erase(
std::remove_if(
stringValue.begin(), stringValue.end(), [](char const c) {
return '\n' == c || '\r' == c || '\0' == c || '\x1A' == c;
}
),
stringValue.end()
);
}
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