knowledge base/tools

curl -T appends the local file name only to a URL ending in a slash, so a query string turns it off

added 2026-09-28·view source

curlhttpclidocumentation

Fact

curl -T photo.jpg https://host/ uploads to /photo.jpg: when the URL has no file part, curl appends the local file name. Add a query string and it stops: curl -T photo.jpg "https://host/?expires=1h" sends PUT /?expires=1h, so the server never learns the name. Checked with curl 8.7.

Why it matters

Upload services in the transfer.sh style take the file name from the path. Documentation that shows options as query parameters on the bare URL produces unnamed uploads (upload.bin, paste.txt) with no error on either side.

How to apply

  • Put options in request headers, e.g. curl -T file -H 'X-Expires: 1h' https://host/.
  • Or spell the name out: curl -T file "https://host/file.txt?expires=1h".
  • Check which request line curl really sends with curl -v before documenting an upload command.

Sources