HTTP requests with curl in scripts in Bash Scripting - Step-by-Step Execution

Concept Flow - HTTP requests with curl in scripts

Start script

↓

Prepare curl command

↓

Execute curl command

↓

Receive HTTP response

↓

Process or display response

↓

End script

The script starts, prepares a curl command to make an HTTP request, executes it, receives the response, then processes or shows the response before ending.

Execution Sample

Bash Scripting

response=$(curl -s https://api.github.com)
echo "$response"

This script sends a silent HTTP GET request to GitHub API and prints the response.

Execution Table

Step	Action	Command/Expression	Result/Output
1	Prepare curl command	curl -s https://api.github.com	Command ready to run
2	Execute curl command	curl -s https://api.github.com	HTTP response JSON received
3	Store response	response=$(curl -s https://api.github.com)	Variable 'response' holds JSON text
4	Print response	echo "$response"	JSON text printed to terminal
5	End script	N/A	Script finishes execution

💡 Script ends after printing the HTTP response stored in 'response' variable.

Variable Tracker

Variable	Start	After Step 3	Final
response	empty	JSON text from GitHub API	JSON text from GitHub API

Key Moments - 3 Insights

Why do we use the -s option with curl in the script?

The -s option makes curl silent, so it does not show progress or errors, only the response. This keeps the output clean as shown in execution_table step 2.

How does the script store the HTTP response in a variable?

Using command substitution $(...), the output of curl is captured and assigned to the variable 'response' as shown in execution_table step 3.

What happens if we omit the quotes around "$response" in echo?

Without quotes, the JSON response might be split or misformatted when printed. Quoting preserves the exact response text, as shown in step 4.

Visual Quiz - 3 Questions

Look at the execution table, what does the variable 'response' contain after step 3?

A The HTTP response JSON text

B The curl command itself

C An empty string

D An error message

💡 Hint

Check the 'Result/Output' column in step 3 of the execution_table.

At which step does the script print the HTTP response to the terminal?

A Step 2

B Step 4

C Step 3

D Step 5

💡 Hint

Look for the 'Print response' action in the execution_table.

If we remove the -s option from curl, what changes in the output?

A The response will be empty

B Curl will not send the HTTP request

C Curl shows progress and error messages along with the response

D The script will fail to run

💡 Hint

Refer to the key moment about the -s option and step 2 in the execution_table.

Concept Snapshot

curl command in scripts:
- Use curl to send HTTP requests
- -s option makes curl silent (no progress shown)
- Capture output with response=$(curl ...)
- Use quotes when printing variables to keep formatting
- Useful for automation and API calls

Full Transcript

This script uses curl to send an HTTP GET request silently to a URL. The response is captured into a variable using command substitution. Then the script prints the response exactly as received. The -s option keeps the output clean by hiding progress info. Quoting the variable when printing preserves the response format. The script ends after printing the response.