InputFile

The InputFile class in utils/InputFile.h allows you to read parameters and options from a file.

class InputFile

InputFile(std::string fileName);

Initializes the class with a certain parameter file. See File format below.

std::istringstream getOption(std::string option, InputFile::OptionType type);

Parameters:

• option – The option to look for in the file.

• type – Whether the option is mandatory or optional. An exception will be thrown if a mandatory option is not found in the file.

Returns:

A stream with the contents of the line containing the option (not including the option). Empty if the option was not found.

enum OptionType

enumerator Optional

enumerator Required

File format

The input file must have the following format:

#Lines starting with '#' will be ignored
#[option] [argument1] [argument2] ...

exampleOption argument1 argument2
#You can have an option with no arguments
justAFlag
#Additionally you can use the special shell option, which will run the rest of the line as a bash command when encountered and wait for it to finish.
shell bash run.sh
shell echo "Hello"

Usage

InputFile inputFile("options.in");
//Read an option of type float
float cutOff;
inputFile.getOption("cutOff")>>cutOff;

//You can have several arguments for an option
//An additional parameter might be passed (Optional or Required, Optional by default) specifying if the option is necessary or not.
//If required is specified and the option is not found, InputFile will issue a CRITICAL error
real3 L;
inputFile.getOption("boxSize", InputFile::Required)>>L.x>>L.y>>L.z;

//Or none!
bool isOptionPresent = bool(inputFile.getOption("someOption"));

//You can check if an option is present in the file by casting to bool somehow
//i.e
if(!(inputFile.getOption("NotPresentOption"))){
  cerr<<"Option not present in the file!!!"<<endl;
}

//Finally you can check if the option not only exists but has the correct number/type of arguments
int anInt;
float aFloat;
std::string aString;
if(!(inputFile.getOption("someOption")>>anInt>>aFloat>>aString)){
   cerr<<"Some parameter missing in the option!"<<endl;
}

Note

getOption will return an std::istringstream, so you can work with its output as such.