Problem removing backslash characters on std::string - c++

Question

I'm trying to execute CMD commands which I'm getting deserializing a JSON message.
When I deserialize message, I store the value in a std::string variable whose value is "tzutil /s \"Romance Standard Time_dstoff\"":
I would like to remove backslash characters ('\') when I receive commands with floating quotes parameters (e.g."tzutil /s "Romance Standard Time_dstoff"").
std::string command = "tzutil /s \"Romance Standard Time_dstoff\""; //Problem
system(command.c_str());
Are there any way to do it?
I will appreciate any kind of help.

Answer 1

If you wish to remove all occurrences the character then you may use
#include <algorithm>
str.erase(std::remove(str.begin(), str.end(), char_to_remove), str.end());
If you wish to replace them with another character then try
#include <algorithm>
std::replace(str.begin(), str.end(), old_char, new_char);

Answer 2

Here is a function I made in C++ for one of my own projects for replacing sub-strings.
std::string
Replace(std::string str,
const std::string& oldStr,
const std::string& newStr)
{
size_t index = str.find(oldStr);
while(index != str.npos)
{
str = str.substr(0, index) +
newStr + str.substr(index + oldStr.size());
index = str.find(oldStr, index + newStr.size());
}
return str;
}
int main(){
std::string command = GetCommandFromJsonSource();
command = Replace(command, "\\\"", "\""); // unescape only double quotes
}

Answer 3

Although the source code of your program does contain, the string represented by the literal doesn't contain any backslashes, as demonstrated by the following example:
std::string command = "tzutil /s \"Romance Standard Time_dstoff\""; //Problem
std::cout << command;
// output:
tzutil /s "Romance Standard Time_dstoff"
As such, there is nothing to remove from the string.
Backslash is an escape character. \" is an escape sequence that represents a single character, the double quote. It is a way to type a double quote character within a string literal without that quote being interpreted as the end of the string instead.
To write a backslash into a string literal, you can by escaping it with a backslash. The following string does contain backslashes: "tzutil /s \\"Romance Standard Time_dstoff\\"". In this case, removing all backslashes can be done like so:
command.erase(std::remove(command.begin(), command.end(), '\\'), command.end());
However, simply removing all instances of the character might not be sensible. If your string contains escape sequences, what you probably should want to do instead is to unescape them. This is somewhat more complicated. You wouldn't want to remove all backslashes, but instead replace \" with " and \\ with \ and \n with a newline and so on.

Answer 4

You can use std::quoted to convert from and to a string literal.
#include <iomanip> // -> std::quoted
#include <iostream>
#include <sstream>
int main() {
std::istringstream s("\"Hello world\\n\"");
std::string hello;
s >> std::quoted(hello);
std::cout << std::quoted(s) << ": " << s;
}