Large downloads can fail due to interruptions, wasting time and bandwidth if restarted from scratch. cURL supports resuming if the server allows HTTP Range requests, enabling download continuation from the last received byte.
This functionality is invaluable for unreliable connections or huge files. If partial content is supported, cURL seamlessly resumes rather than restarting, improving efficiency and conserving resources.
Resuming downloads aids in resource management, ensuring smooth retrieval even under challenging network conditions.
Steps to resume a download using cURL:
- Open a terminal.
- Start downloading a large file.
$ curl --remote-name "https://www.example.com/largefile.zip"
- Interrupt the download or let it fail.
A partial file is saved, ready for resumption.
- Resume the download with --continue-at -.
$ curl --continue-at - --remote-name "https://www.example.com/largefile.zip"
The server must support HTTP Range requests.
- Check file size or integrity with checksums.
$ ls -l largefile.zip $ sha256sum largefile.zip
Validation ensures a complete, correct file.
- If resuming fails, restart without --continue-at.
No partial content support means a full restart is needed.
- Remove partial files if corrupted.
$ rm largefile.zip.part
Cleaning up avoids confusion in future downloads.
Mohd Shakir Zakaria is a cloud architect with deep roots in software development and open-source advocacy. Certified in AWS, Red Hat, VMware, ITIL, and Linux, he specializes in designing and managing robust cloud and on-premises infrastructures.
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