cURL flags I use the most

curl.md

cURL flags I use the most

Context

I always see commands like curl -LsS https://www.example.com over the internet, I never remember what does each flag do, and man curl is overwhelming.

This is the list of the flags I use the most.

Flags

Flag	Description
-A, --user-agent <ua>	set the user agent string ("" removes header, " " empty header)
-b, --cookie <data-or-file>	reads cookie data
-c, --cookie-jar <file>	saves cookie data
-D, --dump-header <file>	write headers to <file>
-d, --data <data>	sends a POST request, see notes after table
-f, --fail	fail silently
-H, --header <header>	set an HTTP header (ex. -H "Host: example.com")
-I, --head	make an HTTP HEAD request to retrieve only headers
-i, --include	include http headers in the output
-J, --remote-header-name	when used with -O, it takes the filename from Content-Disposition
-k, --insecure	allow "untrusted" certs like self-signed ones
-L, --location	follow HTTP 3xx redirects
-O, --remote-name	use the filename from the url
-o, --output <file>	write output to <file> instead of stdout
-q, --disable	ignore ~/.curlrc file
-r, --range <range>	retrieves a byte range
-S, --show-error	when used with -s, it shows an error message on error
-s, --silent	do not print the progress, only the data
-T, --upload-file <path>/	sends a file (trailing / needed); uses HTTP PUT method
-u, --user <user:password>	sets the Authentication header, see notes
-v, --verbose	makes curl verbose, see notes after table
-X, --request <method>	set the http method (ex. GET, POST, etc.)
-#, --progress-bar	use a progress bar (i.e. ############################## 100%)
-:, --next	reset previously set flags for next request (except -v or --trace)
--basic	use Basic HTTP Authentication (this is the default with -u)
--create-dirs	creates dirs like mkdir -p
--data-binary <data>	like -d, but data is binary, does NOT set application/octet-stream
--data-raw <data>	like -d, but treats @ as character
--data-urlencode <data>	like -d, but encodes data
--dns-servers	comma-separated DNS servers to resolve the request
--fail-early	when doing multiple requests, abort them if one fails
--fail-with-body	like -f, but outputs the body
--oauth2-bearer <token>	sets the Authentication: Bearer token
--output-dir <dir>	when used with -O or -o, sets the path to store the files
--proto-default <proto>	default protocol
--remote-name-all	when saving multiple files, treat all as -O

Notes about -d, --data

• Sets application/x-www-form-urlencoded if no Content-Type header
• Does NOT do url encoding (see --data-urlencode)
• Reads url encoded values and treats them as /^@(?<filename>.+)|(?<value>.*)$/ (see --data-raw)

Notes about -u, --user <user:password>

• Uses --basic by default
• Can be combined with many options, such as --anyauth, --aws-sigv4, --basic, --digest, --location-trusted, --negotiate, --ntlm, --oauth2-bearer, etc.
• NOTE: The options above are not exhaustive

Notes about -v, --verbose

• Lines starting with >: Headers sent by curl
• Lines starting with <: Headers received by curl
• Lines starting with *: Extra info provided by curl

NOTE: Use --trace if you need even more debug output