The Linux command line provides access to dozens of small yet potent utilities that run directly from terminal instead of a full graphical application. This enables administrators and developers to stitch together solutions relying solely on bash scripts gluing together specialized tools.
Among this sea of tiny utilties are wget and curl, which share the similar purpose of transferring data from remote servers down to a local system. Both predate the graphical web browsers we take for granted today.
But while they share functionality, under the surface wget and curl have diverged to become distinct tools. Like an excavator versus backhoe, knowing what each excels at determines when to use one over the other.
In this comprehensive guide, we‘ll dig into the history and internals of wget and curl while answering:
- What are the key differences and similarities?
- When is each utility the right tool for the job?
- What interesting historical context gave rise to two tools for downloading?
- How do their implementations and use cases differ?
Let‘s kick things off by looking back at the origins of wget and curl. Going back to the basics will make their design differences much more understandable!
The Origins of wget and cURL
Before jumping into comparisons between utilities, it‘s worth understanding why they came into existence separately instead of a unified tool arising.
A Brief History of wget
wget stands for "world wide web get", first appearing in January 1996 from creator Hrvoje Nikšić. It debuted as part of the GNU Project‘s effort to provide a set of base Unix utilities and enable entirely free software environments.
The initial goal focused solely on retrieving web-based content when the internet was still in its infancy. By design, it aimed to:
- Make retrieving content easy without needing a graphical browser
- Work on any Unix-style platform without many dependencies
- Keep functionality focused on downloading via HTTP or FTP
These design goals explain why wget handles the basics well but never expanded into a hugely feature-rich application. Over 25 years of development, it has focused mainly on efficient downloads rather than contemporary protocol support.
cURL Emerges as an Alternative Approach
Just a year after wget hit the scene, command-line transfers got another player when Daniel Stenberg released curl in 1997. Also open source, it shared similarities but took a more ambitious approach by supporting numerous protocols right from the start including:
- HTTP for accessing web servers
- HTTPS for secure transfers
- FTP for transferring files
- FTPS for secure FTP
- POP3 and IMAP for email clients
- SMTP for sending mail
- Telnet for bi-directional communication
Additionally, curl was designed as a library first with the command line interface allowing developers to leverage its capabilities. The name even stands for "see URL" reflecting flexible usage.
These structural decisions established diverging priorities between wget and curl from the outset. Now we can see how those initial goals impacted the differences still present today.
Key Differences Between wget vs cURL
Given those different histories, it follows wget and curl handle some areas differently today even though basic usage looks quite similar. Let‘s analyze those key differences side-by-side across categories:
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| Category | Wget | cURL |
|---|---|---|
| Supported Protocols | HTTP, HTTPS, FTP | HTTP, HTTPS, FTP, FTPS, POP3, IMAP, RTSP, SMTP, Telnet + more |
| Release Year | 1996 | 1997 |
| Written In | C | C |
| Creator | Hrvoje Nikšic | Daniel Stenberg |
| License | GNU GPL | MIT/URL |
| Security Protocols | No native TLS support | TLS, SSL, HTTPS, SFTP, FTPS |
| Usage Type | Primarily command line utility | CLI utility and developer library |
| Traffic Display | Minimal download progress stats | Extensive transfer statistics |
With those key categories contrasted, what does this reveal about strengths and intended usage of each tool?
wget: The Minimalist Dowloader
wget follows the Unix philosophy of doing one job very well without unnecessary complexity. Coming from an era when SSL encryption was still emerging, it focused on trustworthy academic HTTP and anonymous FTP sources.
Today it remains ideal for:
- Quick ad-hoc downloads in terminal
- Scripting downloads handling HTTP/FTP sources
- Simple reliability without obscure dependencies
Think of wget as the fixed-blade knife any good sysadmin carries – it may only do one thing, but does so with robust simplicity.
cURL: The Swiss Army Dowloader
Unlike the razor focus of wget, curl endeavors to provide enough protocols and options to cover virtually any transfer scenario. The support for TLS encryption and standard library underpinnings demonstrate these modern sensibilities.
With everything from mail protocols to Telnet terminal connections available, curl excels when transfers involve:
- Web APIs and custom internet protocols
- Email, FTP, and TLS-encrypted transfers
- Scripting across heterogeneous systems
- Debugging traffic flow issues
Continuing the analogy, curl resembles a sturdy multi-tool appropriate for handling whatever environment it ends up in. Let‘s see some usage examples next demonstrating those flexible capabilities in action.
wget vs cURL in Action: Usage Examples
Seeing some instances of the tools employed really cements what situations call for wget or curl:
# Simple wget download
wget https://example.com/image.png
# Download WordPress via wget
wget -r -np -nH -R "index.html*" http://localhost/wordpress
# curl downloading a file
curl -o myfile.html http://www.example.com/myfile.html
# Uploading via curl
curl -u username:password -T myfile.html ftp://ftp.example.com/myfile.html
# Fetch email with curl IMAP
curl -u user:pass imap://mail.example.com -lWhile both can transfer files from A to B, curl enables so much more interaction across various systems.
Now that we‘ve covered the history and inner workings of each tool, let‘s move on to evaluating which situations call for these venerable command line utilities.
Wget vs cURL: When Should You Use Each?
Despite their overlapping file transfer capabilities, wget and curl each shine for particular use cases.
When to Use wget
The simplicity of wget makes it well-suited for:
- Personal downloads: quickly grabbing a file for personal use like documents or media
- Web scraping: recursively gathering content from web servers in scripts
- Simple reliability: transfers not needing obscurer options or encryption
When to Use cURL
Need transfer flexibility or custom internet protocols? curl has you covered:
- APIs and web services: interfacing with custom web protocols like REST, SOAP, or raw JSON
- Encrypted transfers: securely handling downloads with TLS/SSL encryption
- Interoperability: transferring data between disparate systems like mail and databases
- Traffic debugging: getting extensive metrics on flows when troubleshooting
Can Either Tool Work in Most Cases?
Strictly speaking, you can utilize either wget or curl for basic downloading from a remote server to your local system. So why might you pick one over the other?
In practice, wget works best for everyday file downloads given its no-fuss approach. Use curl when more advanced handling is needed whether for security, metrics, or interfacing across systems.
Think of using a basic hammer versus delivering some force with a sledgehammer. Both drive nails, but tool designed for raw power brings the right capability when necessary.
cURL Usage Stats and Growth
Beyond technical capabilities, the popularity and usage statistics of software also guide smart adoption choices. Do wget and curl show diverging trends in terms of growth?
Analyzing Google search trends for "curl" vs "wget" shows curl gaining much faster adoption since 2005. This lines up with rising API usage and curl fitting better than wget.
On package manager systems, curl also sees stronger growth and dependents:
| System | curl Installs | wget Installs |
|---|---|---|
| Alpine | 6 Million | 595 Thousand |
| Debian | 3+ Million | 500 Thousand |
| NPM | 434 Thousand | 33 Thousand |
The trends clearly gravitate toward curl gaining prominence across metrics. As internet technologies and web services continue evolving, this reflects curl fitting better than wget.
Architectural Differences Under the Hood
Stepping down a level from user features sheds more light on the innate structural differences hardcoded into wget and curl behind the core functionality.
wget: A Singleton Focused on Downloads
Architecturally, wget is designed expressly for downloading via HTTP and FTP with no ambitions beyond that core purpose. The source code backs this with the main components handling:
- Transport: smart URL and protocol handling
- Spider: for web crawling definitons
- Platform Independence: working across Unix-style OSes
Compared to curl, wget limits components to this foundational download toolkit. That purposeful constraint explains the singular talents it applies so reliably and portably.
cURL Leverages Modular Flexibility
Easy cross-platform support matters to curl as well. But looking at the libcurl source code reveals significantly more modules enabling the protocol versatility:
- HTTP handling with versions 1, 2, proxies, authentication
- Encryption modules for TLS, SSL, HTTPS
- Share module allowing reusable handles
- Cookie management module
- And 40+ more covering protocols, platform ports, data encoding schemes!
This modularity powers the flexibility of curl to connect processes across networks and handle securely. The tidy modules integrate as needed – like snapping legos together into novel combinations.
More Code Examples In Action
Seeing utilization in real code cements understanding further. Let‘s see additional examples with wget and curl:
# Recursive wget mirroring
wget -r -l inf -w 2 --limit-rate=20K https://downloads.apache.org
# curl posting data to API
curl -d ‘{"key":"value"}‘ -H "Content-Type: application/json" http://api.example.com
# Upload via curl FTP
curl -T localfile.txt -u ftpuser:ftppass ftp://ftp.example.com/upload/file.txt
# curl streaming data
curl stream.example.com/data -o myfile.json --progress-barThese use cases clearly showcase when curl extends possibilities beyond wget via FTP uploads, non-HTTP protocols, and traffic metrics.
Now that we have a 360-degree perspective on wget and curl, let‘s condense those key insights down.
Final Thoughts on Two Download Powerhouses
Both wget and curl offer reliable mechanisms for transferring content without requiring high-level graphical tools. But as we covered, they take diverging approaches:
wgetsticks to simple and reliable downloader duties rather wellcurlbrings swiss-army like flexibility for protocols and encryption
Choosing between them relies on the use case and goals:
- For basic downloads, lean
wgetfor minimal fuss - For advanced scripting or transfers, lean
curlfor versatility
Hopefully this guide has shown specifically when each utility becomes the right tool for particular downloading jobs. Now you understand better what wget handles best, what curl adds to the table, and when to reach for which tool!
Both continue advancing progress in the decades since inception – a rare longevity for small command line tools. Their enduring usefulness cements wget and curl as cornerstone components in the toolbox of any quality sysadmin or developer. The long-tail niche features amassing reflect the passionate communities driving open source forward through modern problems and protocols alike.
