UNIX Sorting & Pipe System

These flashcards cover the key concepts, commands, and functions from the UNIX Sorting & Pipe System lecture notes.

What does 'wc' stand for and what does it do?

Word count; it reports the number of lines, words, and characters in a file.

What is the main function of the 'sort' command?

It sorts the lines of a file into alphabetical order.

What does the 'uniq' command do?

It removes duplicate copies of a line from a file, only if they are adjacent.

What are the three types of streams in UNIX?

stdin (input), stdout (output), and stderr (error messages).

How can you redirect output to a file in UNIX?

You can use the '>' operator to redirect output from stdout to a file.

What happens when you use '>>' in UNIX?

It appends output to a file instead of overwriting it.

What is the purpose of pipes in UNIX?

Pipes connect the output of one program to the input of another.

How do you ensure error messages are redirected to a specific file?

You can use '2>' to redirect stderr to a file.

What command would you use to append stderr messages to an error file?

ls /bin/doesntExist 2>> errorFile.

What is a key difference between 'stdout' and 'stderr'?

stdout is for normal output, while stderr is specifically for error messages.