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[ Linux Command Encyclopaedia](#) * * * ## What is the dirname Command `dirname` is a simple but practical command-line tool in Linux/Unix systems, used to extract the directory part from a file path. It helps you quickly get the parent directory from a path without manually parsing strings. ### Basic Functionality * **Input**: A file path string * **Output**: The directory part of the path (i.e., content after removing the last slash) * * * ## Command Syntax dirname filename... ### Parameter Description * **Filename**: Can be one or more file paths (supports absolute and relative paths) * **...**: Indicates that multiple file paths can be processed simultaneously ### Option Parameters While `dirname` doesn't require options in most cases, the GNU version supports the following standard options: | Option | Description | | --- | --- | | `-z` | Use NUL character () to separate output, instead of newline | | `--help` | Display help information | | `--version` | Display version information | * * * ## How It Works The `dirname` command processes paths through the following steps: 1. Remove all trailing slashes (/) from the path 2. Remove the last slash and all characters after it 3. If the result is empty, output "." (current directory) ### Processing Flowchart !(#) * * * ## Usage Examples ### Basic Usage ## Example $ dirname /home/user/docs/file.txt /home/user/docs $ dirname relative/path/to/file relative/path/to ### Processing Multiple Files ## Example $ dirname /a/b/c.txt /x/y/z.txt /a/b /x/y ### Special Path Handling ## Example $ dirname /usr/bin/ # Note the trailing slash /usr $ dirname file.txt # Only filename . $ dirname / # Root directory / ### Using in Scripts ## Example #!/bin/bash # Get the directory where the script is located SCRIPT_DIR=$(dirname "$0") echo "Script directory: $SCRIPT_DIR" # Get the directory of config file path CONFIG_PATH="/etc/app/config.cfg" CONFIG_DIR=$(dirname "$CONFIG_PATH") echo "Config directory: $CONFIG_DIR" * * * ## Common Application Scenarios ### 1. Get Script's Directory ## Example #!/bin/bash # Get the absolute path where the script is located SCRIPT_DIR=$(dirname "$(readlink -f "$0")") echo "Script location: $SCRIPT_DIR" ### 2. Build Relative Paths ## Example # Assuming we know the file is in a subdirectory of a certain directory BASE_DIR="/var/log" FULL_PATH="$BASE_DIR/app/error.log" # Get the log directory LOG_DIR=$(dirname "$FULL_PATH") ### 3. Use with basename ## Example # Decompose the full path FULL_PATH="/home/user/docs/report.pdf" DIR=$(dirname "$FULL_PATH") FILE=$(basename "$FULL_PATH") echo "Directory: $DIR" echo "Filename: $FILE" * * * ## Notes **Symbolic Links**: `dirname` does not resolve symbolic links. To resolve them, use with `readlink` ## Example dirname "$(readlink -f "/path/with/symlink")" **Space Handling**: When the path contains spaces, ensure quotes are used ## Example dirname "/path/with spaces/file.txt" **Relative Paths**: The output will maintain the relative path form ## Example $ dirname ../parent/file.txt ../parent **Empty Input**: If no argument is provided, the GNU version outputs ".", but this is not POSIX standard behavior * * * ## Comparison with Similar Commands | Command | Function | Example Input | Example Output | | --- | --- | --- | --- | | `dirname` | Extract directory part | /a/b/c.txt | /a/b | | `basename` | Extract filename part | /a/b/c.txt | c.txt | | `realpath` | Get absolute path (resolve symlinks) | ../file | /full/path/to/file | * * * ## Practice Exercises Create a test file and get its directory path ## Example touch /tmp/testfile dirname /tmp/testfile Write a script that displays the directory where it itself is located ## Example #!/bin/bash echo "This script is located at: $(dirname "$0")" Try handling paths with spaces and special characters ## Example mkdir -p "/tmp/my dir" touch "/tmp/my dir/special file.txt" dirname "/tmp/my dir/special file.txt" * * Linux Command Encyclopaedia](#)