bash how to check if a symlink exists as a file or directory

To check if a file/directory is a symlink in bash:

if [ -L /some/path/file ]; then echo "OK we're a symlink" fi

That's all there is to it and then you can see if the symlink target already exists.

Why it is important to know if a file or directory is a symlink:

Data Integrity: Deleting a symlink won't delete the target file or directory. Conversely, deleting the target will render the symlink useless, often termed as a "dangling link." Recognizing symlinks can help prevent unintentional data loss or broken references.
Security: Malicious symlinks can be used to trick users into modifying or deleting critical files inadvertently. Knowing how to identify and verify symlinks can protect against potential security threats.
Disk Usage and Management: Since a symlink takes up very little space (as it's essentially a pointer) and the data is stored in the target file/directory, it's crucial to understand this when assessing disk usage. You might think you have duplicated data when, in reality, you have multiple symlinks pointing to the same data.
Backup and Restoration: Some backup utilities might only backup the symlink and not the target. If the target is not backed up separately, it could lead to data loss. Recognizing symlinks ensures that backup strategies are comprehensive.
Data Consistency: Changing the content of the target file or directory will immediately reflect across all symlinks pointing to it. Without realizing this behavior, one might inadvertently affect various applications or processes relying on that data.
System Configuration and Troubleshooting: Symlinks are commonly used in system configurations, like in /etc directories on UNIX-like systems. Knowing which files or directories are symlinks can help troubleshoot issues related to system or application configurations.
Development and Deployment: In software development and deployment, symlinks can be used for version management, enabling quick switches between versions or configurations. Developers and system administrators need to understand symlink behavior to effectively manage and deploy software.
Redundancy Avoidance: Symlinks can help avoid unnecessary data duplication by allowing different locations or applications to reference the same file or directory.
Navigation and Organization: Understanding symlinks can assist users in navigating the filesystem more efficiently. They can trace back to the original file or directory to get a better grasp of data organization.
Permissions and Ownership: The permissions and ownership of a symlink can be different from its target. Understanding this distinction is crucial when setting up access controls and managing user permissions.