Managing Files, Links, and Redirection in Linux

Table of Contents

• File Links in Linux
  • Soft Links (Symbolic)
  • Hard Links
• Creating Links with ln
• Input and Output Redirection
  • Standard Output (stdout)
  • Appending Output
  • Standard Input (stdin)
  • Standard Error (stderr)
• Conclusion

Description
Learn how to manage files from the command line, create soft and hard links, and use input/output redirection in Linux. Includes clear examples for stdout, stderr, and stdin.

Managing Files, Links, and Redirection in Linux — A Practical Guide

Whether you're preparing for RHCSA, working in DevOps, or just learning Linux, mastering file links and I/O redirection is essential. This guide walks through soft vs hard links and how to use stdin, stdout, and stderr redirection with clear, real-world examples.

File Links in Linux

Every file on a Linux filesystem has an inode, which is like a pointer to where the file lives on the disk.

There are two types of links you can create to refer to a file:

Soft Links (Symbolic)

• A soft link points to the original file path.
• If the original file is deleted or renamed, the link is broken.
• Works across different filesystems. Example ln -s /home/user/original.txt shortcut.txt Ones delete, soft link is broken

Hard Links

A hard link points directly to the file's inode.
Deleting or renaming the original file doesn’t break the link.
Cannot span across different filesystems.
ln /home/user/original.txt clone.txt

Creating Links with ln

Command	Description
ln file1 file2	Creates a hard link
ln -s file1 linkname	Creates a symbolic (soft) link

Input and Output Redirection

Linux uses three default data streams

Stream	Description	File Descriptor
stdin	Standard Input	0
stdout	Standard Output	1
stderr	Standard Error	2

Standard Output (stdout)

By default, command output shows in the terminal. You can redirect it to a file using >
ls -l > listings
pwd > findpath
This overwrites the file if it exists.

Appending Output

Use >> to append to an existing file without overwriting:
ls -la >> listings
echo "Hello World" >> findpath

Standard Input (stdin)

Use < to provide input from a file to a command

cat < listings
mail -s "Office memo" [e-mail] < memoletter

Standard Error (stderr)

Redirect errors using 2>
ls -l /root 2> errorfile
telnet localhost 2> errorfile

To redirect both output and errors to the same file
command > output.txt 2>&1

Or, split them
command > out.txt 2> err.txt

Conclusion

Understanding how to manage links and redirect input/output gives you more control over how Linux handles files and processes. Whether you're scripting, debugging, or configuring servers, these tools will save you time and help avoid mistakes.