Find out the current working directory in C/C++

To find the Current Working Directory (CWD) in C or C++ is like asking your program: "Hey, where am I right now?". Simply we can say that it is like a folder of your program which is present and used to operate in.

We can use functions like getcwd() from unistd.h in C/C++ or filesystem::current_path() from C++17. Below are the list of the ways to achieve this −

• Using getcwd() in C/C++
• Using filesystem in C++17

Using getcwd() Function in C

In C, we use the getcwd() function. This function gets the path to the current working directory. You can provide a buffer (a space in memory to store the result) and its size, and the function fills it with the directory path.

Syntax

#include <unistd.h>
char *getcwd(char *buf, size_t size);

Example 1: Basic Usage of getcwd()

In this example, we ask the operating system for the current working directory using the getcwd() function −

Note: On Windows, you may need to use _getcwd() from <direct.h> instead of getcwd().

#include <stdio.h>
#include <unistd.h>

int main() {
    char cwd[1024]; /* Buffer to store the directory path */
    
    if (getcwd(cwd, sizeof(cwd)) != NULL) {
        printf("Current working directory: %s\n", cwd);
    } else {
        perror("getcwd() error"); /* Prints error if getcwd() fails */
    }
    return 0;
}

Current working directory: /home/user/project

Example 2: Using NULL Buffer for Dynamic Allocation

When you pass NULL as the buffer, getcwd() allocates memory automatically −

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int main() {
    char *cwd = getcwd(NULL, 0); /* Automatic memory allocation */
    
    if (cwd != NULL) {
        printf("Current working directory: %s\n", cwd);
        free(cwd); /* Free the allocated memory */
    } else {
        perror("getcwd() error");
    }
    return 0;
}

Current working directory: /home/user/project

Using filesystem::current_path() in C++17

In C++17, we can achieve the same using the <filesystem> library. It provides an elegant and modern way to get the current working directory.

Syntax

#include <filesystem>
std::filesystem::current_path();

Example

In this example, we use the modern C++17 approach to get the current working directory −

Note: You may need to compile with -std=c++17 flag and link with -lstdc++fs on some compilers.

#include <iostream>
#include <filesystem>

namespace fs = std::filesystem;

int main() {
    std::cout << "Current path is: " << fs::current_path() << std::endl;
    return 0;
}

Current path is: "/home/user/cpp17"

Comparison

Conclusion

The getcwd() function is the standard C approach for getting the current working directory, while std::filesystem::current_path() offers a modern C++17 alternative. Both methods are effective for determining your program's current location in the filesystem.