How to Get Absolute Path in Ubuntu Linux

Working with files in Ubuntu often requires knowing the exact location of an item within the directory structure. While relative paths are convenient for navigation, scripts and system configurations frequently demand the full absolute path. This article explains the specific commands used to convert a relative file reference into its complete absolute path within the Ubuntu terminal.

Using the realpath Command

The most straightforward command to display the absolute path of a relative file reference is realpath. This utility is part of the GNU coreutils package, which is installed by default on Ubuntu. It resolves all symlinks and returns the canonicalized absolute filename.

To use it, open your terminal and type the following command followed by the file or directory name:

realpath filename.txt

If the file is located in a subdirectory, you can pass the relative path directly:

realpath ./documents/report.pdf

The terminal will output the full path starting from the root directory, such as /home/user/documents/report.pdf.

Using the readlink Command

An alternative method is using the readlink command with the -f flag. This option forces readlink to follow symlinks and canonicalize the path, effectively providing the absolute path similar to realpath.

The syntax is as follows:

readlink -f filename.txt

This command is particularly useful if realpath is unavailable on a minimal system, though both are standard on modern Ubuntu installations.

Why Absolute Paths Matter

Relative paths depend on your current working directory, which can change during script execution or user navigation. Absolute paths remain constant regardless of where you are in the filesystem. Using the commands above ensures that your scripts, backups, and system links reference the correct location every time, preventing errors caused by directory mismatches.