How to use the command 'look' (with examples)

The ’look’ command is used to search lines in a sorted file. It provides a way to quickly search for lines that match a specific prefix and also has an option to ignore case.

Use case 1: Look for lines which begins with the given prefix

Code:

look prefix path/to/file

Motivation:

You might want to use this use case when you have a sorted file and need to search for lines that start with a specific prefix. This can be useful in situations where you have a large file and need to quickly find relevant lines based on a specific pattern.

Explanation:

• look: The command itself.
• prefix: The prefix to search for in the lines of the file.
• path/to/file: The path to the sorted file to search in.

Example output:

If we have a sorted file named ’names.txt’ with the following contents:

apple
banana
cherry
grape

And we run the command look b names.txt, it will search for lines starting with ‘b’ and the output will be:

banana

Use case 2: Look for lines ignoring case

Code:

look --ignore-case prefix path/to/file

Motivation:

Sometimes you may want to search for lines in a case-insensitive manner. This use case allows you to do just that. It can be beneficial when you want to search for a prefix regardless of whether it is in uppercase or lowercase.

Explanation:

• look: The command itself.
• --ignore-case: An option to specify that the search should be case-insensitive.
• prefix: The prefix to search for in the lines of the file.
• path/to/file: The path to the sorted file to search in.

Example output:

For instance, if we have a sorted file named ‘fruits.txt’ with the following contents:

Apple
Banana
Cherry
Grape

And we run the command look --ignore-case ba fruits.txt, it will search for lines starting with ‘ba’ while ignoring the case and the output will be:

Banana

Conclusion:

The ’look’ command provides a simple way to search for lines in a sorted file. Whether you need to search for lines based on a specific prefix or want to perform a case-insensitive search, ’look’ can help you quickly find the desired lines.