1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Long: etag-compare 5Arg: <file> 6Help: Pass an ETag from a file as a custom header 7Protocols: HTTP 8Added: 7.68.0 9Category: http 10Multi: single 11See-also: 12 - etag-save 13 - time-cond 14Example: 15 - --etag-compare etag.txt $URL 16--- 17 18# `--etag-compare` 19 20This option makes a conditional HTTP request for the specific ETag read 21from the given file by sending a custom If-None-Match header using the 22stored ETag. 23 24For correct results, make sure that the specified file contains only a 25single line with the desired ETag. An empty file is parsed as an empty 26ETag. 27 28Use the option --etag-save to first save the ETag from a response, and 29then use this option to compare against the saved ETag in a subsequent 30request. 31