Cheat Sheet logoCheat Sheet Today
cURL HTTP and API Workflows/Conditional request by modification time

Only fetch if the remote file is newer than a local file.

Back to sheetBrowse commands
Sign in to save
Section: Response Inspection

Conditional request by modification time

bash
bash
curl -z local-copy.txt -O https://example.com/local-copy.txt
Explanation

`-z` uses time conditions such as If-Modified-Since.

View in sheet →

Learn the surrounding workflow

Compare similar commands or jump into common fixes when this command is part of a bigger troubleshooting path.

Compare commandsView fixes

Related commands

Same sheet · prioritizing Response Inspection
Save ETag metadata
Store ETag metadata for conditional requests.
OpenIn sheetbashsame section
Conditional request with ETag
Use a saved ETag to avoid downloading unchanged content.
OpenIn sheetbashsame section
Request compressed response
Ask the server for a compressed response body.
OpenIn sheetbashsame section
Write headers to a file
Store response headers separately from the body.
OpenIn sheetbashsame section
Verbose HTTP/TLS details
Show detailed request and response conversation.
OpenIn sheetbashsame section
Full ASCII trace
Capture a detailed ASCII trace of the transfer.
OpenIn sheetbashsame section