How can I run multiple curl requests processed sequentially?

In development or testing, we frequently need to run multiple curl requests sequentially to simulate user behavior or test APIs. There are several approaches to achieve this:

1. Using Shell Scripts

The simplest method is to utilize a Shell script. You can include multiple curl commands, each on a separate line, within a bash script. For example:

bash
#!/bin/bash

# Request login API
curl -X POST http://example.com/api/login -d 'username=user&password=pass'

# Wait for one second
sleep 1

# Request user information API
curl http://example.com/api/userinfo

# Wait for one second
sleep 1

# Request logout API
curl http://example.com/api/logout

This script executes the login, user information retrieval, and logout operations sequentially, with a one-second pause between requests to ensure the server has adequate time to process each preceding request.

2. Using Loops

When handling multiple similar requests, a loop can simplify the script. For instance, to sequentially query user information for multiple users:

bash
#!/bin/bash

users=('user1' 'user2' 'user3')

for user in "${users[@]}"
	do
		curl http://example.com/api/userinfo?username=$user
		sleep 1
	done

This script sequentially queries user information for user1, user2, and user3.

3. Using Advanced Scripting Languages

For complex requests requiring response data processing, a more powerful language like Python may be necessary. With Python, you can parse curl's JSON responses and determine subsequent actions based on the data. For example:

python
import requests
import time

users = ['user1', 'user2', 'user3']

for user in users:
    response = requests.post("http://example.com/api/login", data={"username": user, "password": "pass"})
    if response.status_code == 200:
        print(f"Login successful: {user}")
        # Simulate operations
        time.sleep(1)

        userinfo = requests.get(f"http://example.com/api/userinfo?username={user}")
        print(userinfo.json())

        time.sleep(1)

        logout = requests.post("http://example.com/api/logout")
        print(f"Logout: {user}")
    else:
        print(f"Login failed: {user}")

This Python script implements login, user information retrieval, and logout functionality while handling response data for each step.

Summary

Running multiple curl requests sequentially can be achieved through various methods, with the choice depending on specific requirements, environment, and personal preference. Whether using a simple Shell script or a more complex Python script, both effectively automate repetitive tasks in testing and development.