Portable scripting (POSIX compliance) in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print the current working directory in a POSIX-compliant way.

Bash Scripting

echo [1]

Drag options to blanks, or click blank then click option'

Agetcwd

Bcwd

Cpwd

Ddir

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-POSIX commands like 'cwd' or 'getcwd' which may not exist.

Using 'dir' which is not guaranteed to be POSIX-compliant.

The pwd command prints the current working directory and is POSIX-compliant.

2fill in blank

medium

Complete the code to check if a file named 'data.txt' exists in a POSIX-compliant way.

Bash Scripting

if [ [1] "data.txt" ]; then echo "File exists"; fi

Drag options to blanks, or click blank then click option'

A-d

B-e

C-f

D-s

Attempts:

3 left

💡 Hint

Common Mistakes

Using -d which checks only for directories.

Using -f which checks only for regular files.

Using -s which checks if file size is greater than zero.

The -e test checks if a file or directory exists and is POSIX-compliant.

3fill in blank

hard

Fix the error in the script to assign the output of the 'date' command to a variable in a POSIX-compliant way.

Bash Scripting

current_date=[1]

Drag options to blanks, or click blank then click option'

A`date`

B$(date +%Y-%m-%d)

C${date}

D$(date)

Attempts:

3 left

💡 Hint

Common Mistakes

Using ${date} which tries to expand a variable named date.

Using backticks which can cause issues in nested commands.

Using $(date +%Y-%m-%d) when the question wants just the output of date command.

Using $(date) is POSIX-compliant for command substitution.

4fill in blank

hard

Fill both blanks to create a POSIX-compliant loop that prints numbers 1 to 5.

Bash Scripting

i=1
while [ [1] ]; do
  echo $i
  i=[2]
 done

Drag options to blanks, or click blank then click option'

A$i -le 5

B$i -lt 5

C$((i + 1))

D$i + 1

Attempts:

3 left

💡 Hint

Common Mistakes

Using '$i -lt 5' which stops at 4, not 5.

Using 'i=$i + 1' which is not arithmetic expansion.

Using 'i=$i++' which is not POSIX-compliant.

The condition [ $i -le 5 ] checks if i is less or equal to 5, and i=$((i + 1)) increments i in a POSIX-compliant way.

5fill in blank

hard

Fill all three blanks to create a POSIX-compliant script that creates a directory if it does not exist and then changes into it.

Bash Scripting

if [ ! -d [1] ]; then
  [2] [3]
fi

Drag options to blanks, or click blank then click option'

Amyfolder

Bmkdir

C-p

Dcd

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'cd' in the blank where directory creation is expected.

Omitting the '-p' option which is safer for nested directories.

Using a different directory name than 'myfolder'.

The script checks if 'myfolder' directory does not exist, then creates it with mkdir -p. The cd command is not used here because the instruction only asks to create and then change into it, but the blank is only for creation.