Ubuntu Text Processing: Using the cat Command to View File Contents

The `cat` command is a fundamental text processing tool in the Ubuntu system, derived from "concatenate". Its core function is to view and merge file contents. The basic syntax `cat filename` can display a file's content (e.g., viewing `test.txt`). Common options enhance its functionality: `-n` shows line numbers for all lines (including empty ones), `-b` only numbers non-empty lines, and `-s` merges consecutive empty lines. For multi-file processing, you can view multiple files simultaneously (e.g., `cat file1 file2`) or redirect the merged output to a new file using `>` (e.g., `cat a.txt b.txt > new.txt`). Important notes: If the file does not exist, an error will occur, so verify the path. If permissions are insufficient, use `sudo`. The `>` redirection overwrites the target file; it is recommended to back up or use `>>` for appending instead. Despite its simplicity, `cat` is highly practical. By practicing basic operations (e.g., testing different options and merging multiple files), you can quickly master its flexible applications.