In the world of modern Linux web servers, the `cat` command is an essential utility because it enables quick and easy file viewing, combining, and creation. It is a powerful tool for the expert system administrator, and one that can cause problems when used incorrectly. To help ensure its proper usage, this post will discuss common issues encountered when using `cat` and how to fix them.
The most common issue with `cat` is related to formatting. The command will print out each line of the file exactly as it appears, without interpreter insights or special features. This can cause lines to become unreadable or print with extra characters. To counter this, administrators need to use options such as the `-b` and `-n` flags. Adding these to the command will cause `cat` to automatically number the lines within the file, making the text much easier to read. For even more formatting flexibility, administrators can redirect the output of their command to a text editor like nano or vi.
Another major problem arises when performing concatenation, the combining of multiple files into one. This is done using the `cat` command and works by listing all files to be combined as arguments following the command. For example, if I wanted to combine `notes1.txt` and `notes2.txt` into one file I would use `cat notes1.txt notes2.txt > notes3.txt`. This `notes3.txt` would be a combination of each line in the original files. However, if the files do not exist or are not located in the same directory as the command, the process will fail. As such, administrators should ensure all necessary files are available before attempting the operation.
Finally, carpal tunnel syndrome can be a real problem when executing `cat` commands regularly as there is a lot of typing involved. To avoid this, I find typing a quick alias at the start of my session helps me immensely. An alias is a line of code that defines a shorter version of a command or set of commands, and in this case I would use `alias cat=”
In conclusion, the `cat` command is a powerful tool in a system administrator’s repertoire, but one that can lead to problems if misused. By understanding the command’s limitations and adding options such as `-b` and `-n` for formatting, as well as aliasing the command, one can avoid many of the most common issues.