Why reading files is constant in Linux CLI - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to read the entire file content using a single command.

Linux CLI

cat [1]

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Aopen

Bread

Cfile.txt

Dwrite

Attempts:

3 left

💡 Hint

Common Mistakes

Using commands like 'read' or 'open' which are not valid in this context.

Forgetting to specify the filename.

The 'cat' command followed by the filename reads and outputs the entire file content.

2fill in blank

medium

Complete the command to read the first 10 lines of a file.

Linux CLI

head -n [1] file.txt

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A15

B5

C20

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Using numbers other than 10 when the question asks for first 10 lines.

Omitting the '-n' option.

The option '-n 10' tells 'head' to show the first 10 lines of the file.

3fill in blank

hard

Fix the error in the command to read a file line by line in a shell script.

Linux CLI

while IFS= read -r [1]; do echo "$line"; done < file.txt

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Aline

Bfile

Ctext

Dinput

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name different from the one echoed inside the loop.

Not specifying a variable after 'read -r'.

The variable 'line' is used to store each line read from the file in the loop.

4fill in blank

hard

Fill in the blank to create a command that counts the number of lines in a file.

Linux CLI

cat file.txt | [1] -l

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Awc

Bhead

Ctail

Dsort

Attempts:

3 left

💡 Hint

Common Mistakes

Using commands like 'head' or 'tail' which do not count lines.

Leaving the blank empty.

The 'wc -l' command counts the number of lines in the piped input.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps words to their lengths for words longer than 3 characters.

Linux CLI

lengths = { [1]: [2] for [3] in words if len([3]) > 3 }

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Aword

Blen(word)

Ditem

Attempts:

3 left

💡 Hint

Common Mistakes

Using inconsistent variable names.

Mapping keys to wrong values.

The comprehension uses 'word' as the variable, maps 'word' to 'len(word)', and iterates over 'word' in words.