basename_realpath_dirname

➜  Learning-ShellScripting git:(main) basename /mnt/c/Users/naras/OneDrive/Documents/Learning-ShellScripting/arg2.sh
arg2.sh
# gives file name

➜  Learning-ShellScripting git:(main) dirname /mnt/c/Users/naras/OneDrive/Documents/Learning-ShellScripting/arg2.sh
/mnt/c/Users/naras/OneDrive/Documents/Learning-ShellScripting
# gives directory name 

In shell scripting, `realpath`, `basename`, and `dirname` are commonly used commands to manipulate file paths. Here’s how each of them works:

### 1. **`realpath`**
   - **Purpose**: Returns the absolute path of a given file or directory.
   - **Usage**: 
     
     realpath [file_or_directory]
     ```
   - **Example**:
     
     realpath ./myfile.txt
     ```
     If you are in `/home/user/project` and `myfile.txt` is in the current directory, it will return:
     ```
     /home/user/project/myfile.txt
     ```

### 2. **`basename`**
   - **Purpose**: Extracts the filename or directory name from a given path.
   - **Usage**: 
     
     basename [file_or_directory_path] [suffix]
     ```
   - **Example**:
     
     basename /home/user/project/myfile.txt
     ```
     Output:
     ```
     myfile.txt
     ```
     If you use a suffix (e.g., `.txt`), it will strip the suffix:
     ```bash
     basename /home/user/project/myfile.txt .txt
     ```
     Output:
     ```
     myfile
     ```

### 3. **`dirname`**
   - **Purpose**: Extracts the directory path from a given file path.
   - **Usage**: 
     
     dirname [file_path]
     ```
   - **Example**:
     
     dirname /home/user/project/myfile.txt
     ```
     Output:
     ```
     /home/user/project
     ```

### Use Case Example:

file_path="/home/user/project/myfile.txt"

# Get the absolute path
absolute_path=$(realpath "$file_path")
echo "Absolute Path: $absolute_path"

# Get the filename
filename=$(basename "$file_path")
echo "Filename: $filename"

# Get the directory name
directory=$(dirname "$file_path")
echo "Directory: $directory"


This script will output the absolute path, filename, and directory name separately.