Help Topic: MOOS-IvP String Parsing Utilities

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MOOS-IvP String Parsing Utilities

The below describe a set of string utilities in the MBUtils library distributed with MOOS-IvP. To use them, add #include "MBUtils.h" in your source code, and add the mbutil library to the list of libraries your code links to, likely in your local CMakeLists.txt file.

The biteString() function    [top]

The biteString() function takes a string and returns everything to the left of the given character. The original string is modified and is everything to the right of the character. 

  string biteString(string, char);

For example: 

  string orig = "temperature = 98";
  string left = biteString(orig, '=');
  cout << "left: [" << left << "]" << endl;
  cout << "orig: [" << orig << "]" << endl;

Produces: 

  left: [temperature ]
  orgi: [ 98];

Notice that the white space to the left and the right of the '=' character are preserved in the result. If your desire is to have these removed, you can invoke biteStringX() instead, described below.

The biteStringX() function    [top]

The biteStringX() function does the same thing as the biteString function but takes the additional step of removing blanks from the ends of the results. 

  string biteStringX(string, char);

For example: 

  string orig  = "temperature = 98";
  string left = biteStringX(orig, '=');
  cout << "left: [" << left << "]" << endl;
  cout << "orig: [" << orig << "]" << endl;

Produces: 

  left: [temperature]
  orgi: [98];

The parseString() function    [top]

The parseString() function takes a string, and a character. It returns a vector of strings where each string is component of the original string separated by the given character. 

  vector<string> parseString(string, char);

For example: 

  string orig = "temperature=98, height=72, weight=150";
  vector<string> str_vector = parseString(orig, ',');
  for(unsigned int i=0; i<str_vector.size(); i++)
    cout << "component: [" << str_vector[i] << "]" << endl;

Produces: 

   component = [temperature=98]
   component = [ height=72]
   component = [ weight=150]

Notice that the white space to the left and the right of the ',' character are preserved in the result.

The parseStringQ() function    [top]

The parseStringQ() works like parseString() except that the character separated is ignored if it is enounctered between double-quotes. 

  vector<string> parseStringQ(string, char);

For example: 

  string orig = "children="john,bob,mary", height=72, weight=150";
  vector<string> str_vector = parseStringQ(orig, ',');
  for(unsigned int i=0; i<str_vector.size(); i++)
    cout << "component: [" << str_vector[i] << "]" << endl;

Produces: 

   component = [children=john,bob,mary]
   component = [ height=72]
   component = [ weight=150]

Notice that the white space to the left and the right of the ',' character are preserved in the result.

The tokStringParse() function    [top]

The tokStringParse() works on a comma-separated list of parameter=value pairs and pulls out the value for a given parameter. The first character argument is the "global" separator, and the second argument is the "local" separator. 

  string tokStringParse(string, string, char, char);

For example: 

  string orig = "temperature=98.1, height=72, weight=150";

  string a = tokStringParse(orig, "temperature", ',', '=');
  string b = tokStringParse(orig, "height", ',', '=');
  string c = tokStringParse(orig, "weight", ',', '=');
  string d = tokStringParse(orig, "age", ',', '=');

  cout << "a: [" << a << "]" << endl;
  cout << "b: [" << b << "]" << endl;
  cout << "c: [" << c << "]" << endl;
  cout << "d: [" << d << "]" << endl;

Produces: 

   a: [98.1]
   b: [72]
   a: [150]
   a: []

This function will also strip leading and trailing white space on its return value.

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