grep in scripts in Bash Scripting - Mini Project: Build & Apply

Using grep in Bash Scripts

📖 Scenario: You work as a system administrator. You often need to find specific words in log files to check system status or errors.Today, you will write a simple bash script that uses grep to search for a word in a text file.

🎯 Goal: Create a bash script that searches for a specific word in a file using grep and shows the matching lines.

📋 What You'll Learn

Create a variable holding the filename

Create a variable holding the search word

Use grep to find the word in the file

Print the matching lines

💡 Why This Matters

🌍 Real World

System administrators often need to search logs for errors or specific messages quickly using scripts.

💼 Career

Knowing how to use <code>grep</code> in scripts helps automate monitoring and troubleshooting tasks in IT jobs.

1

Create the text file

Create a file called log.txt with these exact lines:
error: disk full
info: system rebooted
warning: high memory usage
error: network down

Bash Scripting

# Create the file log.txt with the given lines
# Your code here

Need a hint?

Use cat with a here-document to create the file.

2

Set variables for filename and search word

Create a variable called filename and set it to log.txt.
Create a variable called search_word and set it to error.

Bash Scripting

cat  log.txt
error: disk full
info: system rebooted
warning: high memory usage
error: network down
EOF

# Create variables filename and search_word
# Your code here

Need a hint?

Use = without spaces to assign values to variables.

3

Use grep to find the search word in the file

Use grep with the variable search_word to search inside the file stored in filename. Store the result in a variable called result.

Bash Scripting

cat  log.txt
error: disk full
info: system rebooted
warning: high memory usage
error: network down
EOF

filename="log.txt"
search_word="error"

# Use grep to find search_word in filename and save to result
# Your code here

Need a hint?

Use command substitution $( ) to save grep output to a variable.

4

Print the matching lines

Print the variable result to show the lines containing the search word.

Bash Scripting

cat  log.txt
error: disk full
info: system rebooted
warning: high memory usage
error: network down
EOF

filename="log.txt"
search_word="error"

result=$(grep "$search_word" "$filename")

# Print the result variable
# Your code here

Need a hint?

Use printf or echo to print the variable.