In C++ you will be making a program that can take command like args.
Using command line arguments, allow the program to do the following
If the command is -i, print: Integer, and then print the integer after it.
If the command is -f print: float, and then print the float after it
if the command is -s print: string, and then print the string after it.
If the command is -h print: all the commands, and the syntax
If the command is something not listed, do the same as the -h command.
It doesn't matter the number or the order -- do all the commands that the person typed.
Is someone does a command, but it is not the right syntax -- show the correct syntax.
Example entries into the program:
prog.exe -i 3
prog.exe -f 3.14 -i 6
prog.exe -h
To create a program in C++ that takes command line arguments and performs different actions based on the input, follow these steps:
Step 1: Set up the necessary includes and main function
```cpp
#include <iostream>
#include <string>
int main(int argc, char* argv[]) {
// Your code goes here
return 0;
}
```
Step 2: Implement the logic to handle command line arguments
```cpp
#include <iostream>
#include <string>
int main(int argc, char* argv[]) {
if (argc > 1) {
std::string command = argv[1];
if (command == "-i" && argc > 2) {
std::cout << "Integer: " << std::stoi(argv[2]) << std::endl;
} else if (command == "-f" && argc > 2) {
std::cout << "Float: " << std::stof(argv[2]) << std::endl;
} else if (command == "-s" && argc > 2) {
std::cout << "String: " << argv[2] << std::endl;
} else if (command == "-h") {
std::cout << "Available commands:" << std::endl;
std::cout << "-i <integer> : Print an integer" << std::endl;
std::cout << "-f <float> : Print a float" << std::endl;
std::cout << "-s <string> : Print a string" << std::endl;
std::cout << "-h : Show available commands" << std::endl;
} else {
std::cout << "Invalid command. Please use one of the available commands mentioned with -h." << std::endl;
}
} else {
std::cout << "No command provided. Please enter a valid command." << std::endl;
}
return 0;
}
```
Step 3: Compile the program using a C++ compiler
Save the above code into a file e.g., `prog.cpp` and then compile it using a C++ compiler. For example, you can use `g++`:
```
g++ prog.cpp -o prog
```
Step 4: Run the program with different command line arguments
```
./prog -i 3
Output: Integer: 3
./prog -f 3.14 -i 6
Output: Float: 3.14
Integer: 6
./prog -h
Output: Available commands:
-i <integer> : Print an integer
-f <float> : Print a float
-s <string> : Print a string
-h : Show available commands
./prog -x
Output: Invalid command. Please use one of the available commands mentioned with -h.
```
To accomplish this task, you can follow these steps in C++:
1. Retrieve the command line arguments: In C++, you can access the command-line arguments through the `main` function parameters. The first parameter (`argv`) is an array of strings containing the command line arguments, and the second parameter (`argc`) indicates the number of arguments passed.
2. Implement an if-else statement or switch statement to check the command-line arguments and perform the corresponding actions based on the commands.
3. Parse the command line arguments: To check the command-line arguments, you can iterate through the `argv` array and compare the strings.
4. Handle the different commands: For each command, implement the required actions. Here's an outline of how you can handle each command:
- For the "-i" command, check if the next argument is an integer using `std::stoi`. If it is, print "Integer" and the integer value. If not, display the correct syntax.
- For the "-f" command, check if the next argument is a float using `std::stof`. If it is, print "float" and the float value. If not, display the correct syntax.
- For the "-s" command, print "string" and the following argument.
- For the "-h" command or any other unrecognized command, display all the commands and their syntax.
5. Compile and run the program: After implementing the logic, compile and run the program, passing the desired command line arguments.
Here's an example implementation in C++:
```cpp
#include <iostream>
#include <string>
int main(int argc, char* argv[]) {
for (int i = 1; i < argc; ++i) {
std::string command = argv[i];
if (command == "-i") {
if (i + 1 < argc) {
try {
int value = std::stoi(argv[i + 1]);
std::cout << "Integer: " << value << std::endl;
++i; // Skip the next argument since it has been processed
} catch (std::exception& e) {
std::cout << "Invalid syntax. Usage: -i <integer>" << std::endl;
}
} else {
std::cout << "Missing argument. Usage: -i <integer>" << std::endl;
}
} else if (command == "-f") {
if (i + 1 < argc) {
try {
float value = std::stof(argv[i + 1]);
std::cout << "Float: " << value << std::endl;
++i; // Skip the next argument since it has been processed
} catch (std::exception& e) {
std::cout << "Invalid syntax. Usage: -f <float>" << std::endl;
}
} else {
std::cout << "Missing argument. Usage: -f <float>" << std::endl;
}
} else if (command == "-s") {
if (i + 1 < argc) {
std::cout << "String: " << argv[i + 1] << std::endl;
++i; // Skip the next argument since it has been processed
} else {
std::cout << "Missing argument. Usage: -s <string>" << std::endl;
}
} else {
std::cout << "Unrecognized command: " << command << std::endl;
std::cout << "Usage: -i <integer> | -f <float> | -s <string> | -h" << std::endl;
}
}
return 0;
}
```
After compiling and running the program with different command-line arguments, it will perform the corresponding actions based on the commands passed.