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Learn curl
- Watch video from Traversy Media
- (todo: make more notes here) Amazing twitter thread from Rapid Api on learning Curl: Click here
# Run script without downloading (you need sudo as per your requirement)
sudo curl https://cli-assets.heroku.com/install.sh | sh
# only response body (without response header)
curl localhost:3000
# response body + response headers
curl -i localhost:3000
# -i is alias for --include
# only response headers
curl -I localhost:3000
# -I is an alias for --head
# only response's status code
curl -sI localhost:3000 | head -n1 | awk '{print $2}'
# write output to default route-named-file named i.e., `crash` (CAUTION: overwrites to existing file)
curl -O localhost:3000/crash
# -O is an alias for --remote-name
# download an image
curl -O https://i.imgur.com/5pdde58.jpeg
# Output: Image downloaded to `5pdde58.jpeg` file in current folder.
# LEARN: throws error: curl >> Remote file name has no length!
curl -O localhost:3000/
# write output to custom file (lowercase o) (CAUTION: overwrites to existing file)
curl -o myFile.txt localhost:3000
# -o is an alias for --output
# follow redirect with -L flag
curl -L google.com
# Outputs from www.google.com
#fyi: if don't used www. prefix then curl shows us only the redirect message and informs that the page has moved to www.google.com site.
# upload via FTP
curl -u test@traversymedia.com:123456! -T hello.txt ftp://ftp.traversymedia.com
# download via FTP
curl -u test@traversymedia.com:123456! -O ftp://ftp.traversymedia.com/hello.txt
# Default --request (-X) has GET value:
curl "https://reverberate.ml"
curl --request GET https://reverberate.ml
curl -X GET https://reverberate.ml
# Sending telegram message to target group/channel with a given chat_id
curl -X POST \
-H "Content-Type: application/json" \
-d '{"chat_id": "1", "text": "2", "parse_mode": "HTML"}' \
'https://api.telegram.org/bot<BOT_TOKEN>/sendMessage'
# For using multiple request headers use format like this:
`curl -H "X-Header1: value1" -H "X-Header2: value2" localhost:8080`
#### TIPS:
# Tip: replace GET with POST, PUT, PATCH, etc for such usages!**, https://www.keycdn.com/support/popular-curl-examples#13-get-method
# Tip: Use `log({headers: req.headers});` to log the headers on express server.
# Simple curl requests: https://www.keycdn.com/support/popular-curl-examples
#### OTHER HELPFUL FLAGS:
# -s for silent (it hides progressbar)
# -v for verbose
Using bash variables:
# source: https://stackoverflow.com/a/37632617/10012446
# Using bash variables inside url and body
TELEGRAM_CHAT_ID="---"
TELEGRAM_ACCESS_TOKEN="---"
# Enable Debugging
set -x
curl -X POST \
-H "Content-Type: application/json" \
-d @<(cat <<EOF
{ "chat_id": "$TELEGRAM_CHAT_ID", "text": "hello", "parse_mode": "HTML" }
EOF) \
"https://api.telegram.org/bot$TELEGRAM_ACCESS_TOKEN/sendMessage" \
Q. Wonder what is EOF and how it works?
cat <<EOF
SELECT foo, bar FROM db
WHERE foo='baz'
EOF
# Basically <<EOF allows you to enter multiple lines of text into bash which is normally now allowed and redirect it to anythng you want.
# Online resource: The EOF operator is used in many programming languages. This operator stands for the end of the file. This means that wherever a compiler or an interpreter encounters this operator, it will receive an indication that the file it was reading has ended.
# See better examples of this @ src: https://stackoverflow.com/a/21549836/10012446
Help
$ curl -h
# Usage: curl [options...] <url>
# -d, --data <data> HTTP POST data
# -f, --fail Fail silently (no output at all) on HTTP errors
# -h, --help <category> Get help for commands
# -i, --include Include protocol response headers in the output
# -o, --output <file> Write to file instead of stdout
# -O, --remote-name Write output to a file named as the remote file
# -s, --silent Silent mode
# -T, --upload-file <file> Transfer local FILE to destination
# -u, --user <user:password> Server user and password
# -A, --user-agent <name> Send User-Agent <name> to server
# -v, --verbose Make the operation more talkative
# -V, --version Show version number and quit
#
# This is not the full help, this menu is stripped into categories.
# Use "--help category" to get an overview of all categories.
# For all options use the manual or "--help all".
Help - all
curl -h all
# Output:
# Usage: curl [options...] <url>
# --abstract-unix-socket <path> Connect via abstract Unix domain
# --alt-svc <file name> Enable alt-svc with this cache file
# --anyauth Pick any authentication method
# -a, --append Append to target file when uploading
# --aws-sigv4 <provider1[:provider2[:region[:service]]]> Use AWS
# --basic Use HTTP Basic Authentication
# --cacert <file> CA certificate to verify peer against
# --capath <dir> CA directory to verify peer against
# -E, --cert <certificate[:password]> Client certificate file and pas
# --cert-status Verify the status of the server cert via O
# --cert-type <type> Certificate type (DER/PEM/ENG)
# --ciphers <list of ciphers> SSL ciphers to use
# --compressed Request compressed response
# --compressed-ssh Enable SSH compression
# -K, --config <file> Read config from a file
# --connect-timeout <fractional seconds> Maximum time allowed for
# --connect-to <HOST1:PORT1:HOST2:PORT2> Connect to host
# -C, --continue-at <offset> Resumed transfer offset
# -b, --cookie <data|filename> Send cookies from string/file
# -c, --cookie-jar <filename> Write cookies to <filename> after opera
# --create-dirs Create necessary local directory hierarchy
# --create-file-mode <mode> File mode for created files
# --crlf Convert LF to CRLF in upload
# --crlfile <file> Use this CRL list
# --curves <algorithm list> (EC) TLS key exchange algorithm(s) to
# -d, --data <data> HTTP POST data
# --data-ascii <data> HTTP POST ASCII data
# --data-binary <data> HTTP POST binary data
# --data-raw <data> HTTP POST data, '@' allowed
# --data-urlencode <data> HTTP POST data url encoded
# --delegation <LEVEL> GSS-API delegation permission
# --digest Use HTTP Digest Authentication
# -q, --disable Disable .curlrc
# --disable-eprt Inhibit using EPRT or LPRT
# --disable-epsv Inhibit using EPSV
# --disallow-username-in-url Disallow username in url
# --dns-interface <interface> Interface to use for DNS requests
# --dns-ipv4-addr <address> IPv4 address to use for DNS requests
# --dns-ipv6-addr <address> IPv6 address to use for DNS requests
# --dns-servers <addresses> DNS server addrs to use
# --doh-cert-status Verify the status of the DoH server cert v
# --doh-insecure Allow insecure DoH server connections
# --doh-url <URL> Resolve host names over DoH
# -D, --dump-header <filename> Write the received headers to <filenam
# --egd-file <file> EGD socket path for random data
# --engine <name> Crypto engine to use
# --etag-compare <file> Pass an ETag from a file as a custom head
# --etag-save <file> Parse ETag from a request and save it to a
# --expect100-timeout <seconds> How long to wait for 100-continue
# -f, --fail Fail silently (no output at all) on HTTP e
# --fail-early Fail on first transfer error, do not conti
# --fail-with-body Fail on HTTP errors but save the body
# --false-start Enable TLS False Start
# -F, --form <name=content> Specify multipart MIME data
# --form-escape Escape multipart form field/file names usi
# --form-string <name=string> Specify multipart MIME data
# --ftp-account <data> Account data string
# --ftp-alternative-to-user <command> String to replace USER [nam
# --ftp-create-dirs Create the remote dirs if not present
# --ftp-method <method> Control CWD usage
# --ftp-pasv Use PASV/EPSV instead of PORT
# -P, --ftp-port <address> Use PORT instead of PASV
# --ftp-pret Send PRET before PASV
# --ftp-skip-pasv-ip Skip the IP address for PASV
# --ftp-ssl-ccc Send CCC after authenticating
# --ftp-ssl-ccc-mode <active/passive> Set CCC mode
# --ftp-ssl-control Require SSL/TLS for FTP login, clear for t
# -G, --get Put the post data in the URL and use GET
# -g, --globoff Disable URL sequences and ranges using {}
# --happy-eyeballs-timeout-ms <milliseconds> Time for IPv6 before
# --haproxy-protocol Send HAProxy PROXY protocol v1 header
# -I, --head Show document info only
# -H, --header <header/@file> Pass custom header(s) to server
# -h, --help <category> Get help for commands
# --hostpubmd5 <md5> Acceptable MD5 hash of the host public key
# --hostpubsha256 <sha256> Acceptable SHA256 hash of the host pub
# --hsts <file name> Enable HSTS with this cache file
# --http0.9 Allow HTTP 0.9 responses
# -0, --http1.0 Use HTTP 1.0
# --http1.1 Use HTTP 1.1
# --http2 Use HTTP 2
# --http2-prior-knowledge Use HTTP 2 without HTTP/1.1 Upgrade
# --http3 Use HTTP v3
# --ignore-content-length Ignore the size of the remote resource
# -i, --include Include protocol response headers in the o
# -k, --insecure Allow insecure server connections
# --interface <name> Use network INTERFACE (or address)
# -4, --ipv4 Resolve names to IPv4 addresses
# -6, --ipv6 Resolve names to IPv6 addresses
# --json <data> HTTP POST JSON
# -j, --junk-session-cookies Ignore session cookies read from file
# --keepalive-time <seconds> Interval time for keepalive probes
# --key <key> Private key file name
# --key-type <type> Private key file type (DER/PEM/ENG)
# --krb <level> Enable Kerberos with security <level>
# --libcurl <file> Dump libcurl equivalent code of this comma
# --limit-rate <speed> Limit transfer speed to RATE
# -l, --list-only List only mode
# --local-port <num/range> Force use of RANGE for local port numb
# -L, --location Follow redirects
# --location-trusted Like --location, and send auth to other ho
# --login-options <options> Server login options
# --mail-auth <address> Originator address of the original email
# --mail-from <address> Mail from this address
# --mail-rcpt <address> Mail to this address
# --mail-rcpt-allowfails Allow RCPT TO command to fail for some r
# -M, --manual Display the full manual
# --max-filesize <bytes> Maximum file size to download
# --max-redirs <num> Maximum number of redirects allowed
# -m, --max-time <fractional seconds> Maximum time allowed for transf
# --metalink Process given URLs as metalink XML file
# --negotiate Use HTTP Negotiate (SPNEGO) authentication
# -n, --netrc Must read .netrc for user name and passwor
# --netrc-file <filename> Specify FILE for netrc
# --netrc-optional Use either .netrc or URL
# -:, --next Make next URL use its separate set of opti
# --no-alpn Disable the ALPN TLS extension
# -N, --no-buffer Disable buffering of the output stream
# --no-keepalive Disable TCP keepalive on the connection
# --no-npn Disable the NPN TLS extension
# --no-progress-meter Do not show the progress meter
# --no-sessionid Disable SSL session-ID reusing
# --noproxy <no-proxy-list> List of hosts which do not use proxy
# --ntlm Use HTTP NTLM authentication
# --ntlm-wb Use HTTP NTLM authentication with winbind
# --oauth2-bearer <token> OAuth 2 Bearer Token
# -o, --output <file> Write to file instead of stdout
# --output-dir <dir> Directory to save files in
# -Z, --parallel Perform transfers in parallel
# --parallel-immediate Do not wait for multiplexing (with --paral
# --parallel-max <num> Maximum concurrency for parallel transfers
# --pass <phrase> Pass phrase for the private key
# --path-as-is Do not squash .. sequences in URL path
# --pinnedpubkey <hashes> FILE/HASHES Public key to verify peer a
# --post301 Do not switch to GET after following a 301
# --post302 Do not switch to GET after following a 302
# --post303 Do not switch to GET after following a 303
# --preproxy [protocol://]host[:port] Use this proxy first
# -#, --progress-bar Display transfer progress as a bar
# --proto <protocols> Enable/disable PROTOCOLS
# --proto-default <protocol> Use PROTOCOL for any URL missing a s
# --proto-redir <protocols> Enable/disable PROTOCOLS on redirect
# -x, --proxy [protocol://]host[:port] Use this proxy
# --proxy-anyauth Pick any proxy authentication method
# --proxy-basic Use Basic authentication on the proxy
# --proxy-cacert <file> CA certificate to verify peer against for
# --proxy-capath <dir> CA directory to verify peer against for pr
# --proxy-cert <cert[:passwd]> Set client certificate for proxy
# --proxy-cert-type <type> Client certificate type for HTTPS prox
# --proxy-ciphers <list> SSL ciphers to use for proxy
# --proxy-crlfile <file> Set a CRL list for proxy
# --proxy-digest Use Digest authentication on the proxy
# --proxy-header <header/@file> Pass custom header(s) to proxy
# --proxy-insecure Do HTTPS proxy connections without verifyi
# --proxy-key <key> Private key for HTTPS proxy
# --proxy-key-type <type> Private key file type for proxy
# --proxy-negotiate Use HTTP Negotiate (SPNEGO) authentication
# --proxy-ntlm Use NTLM authentication on the proxy
# --proxy-pass <phrase> Pass phrase for the private key for HTTPS
# --proxy-pinnedpubkey <hashes> FILE/HASHES public key to verify
# --proxy-service-name <name> SPNEGO proxy service name
# --proxy-ssl-allow-beast Allow security flaw for interop for HTT
# --proxy-ssl-auto-client-cert Use auto client certificate for pr
# --proxy-tls13-ciphers <ciphersuite list> TLS 1.3 proxy cipher s
# --proxy-tlsauthtype <type> TLS authentication type for HTTPS pr
# --proxy-tlspassword <string> TLS password for HTTPS proxy
# --proxy-tlsuser <name> TLS username for HTTPS proxy
# --proxy-tlsv1 Use TLSv1 for HTTPS proxy
# -U, --proxy-user <user:password> Proxy user and password
# --proxy1.0 <host[:port]> Use HTTP/1.0 proxy on given port
# -p, --proxytunnel Operate through an HTTP proxy tunnel (usin
# --pubkey <key> SSH Public key file name
# -Q, --quote <command> Send command(s) to server before transfer
# --random-file <file> File for reading random data from
# -r, --range <range> Retrieve only the bytes within RANGE
# --raw Do HTTP "raw"; no transfer decoding
# -e, --referer <URL> Referrer URL
# -J, --remote-header-name Use the header-provided filename
# -O, --remote-name Write output to a file named as the remote
# --remote-name-all Use the remote file name for all URLs
# -R, --remote-time Set the remote file's time on the local ou
# -X, --request <method> Specify request method to use
# --request-target <path> Specify the target for this request
# --resolve <[+]host:port:addr[,addr]...> Resolve the host+port t
# --retry <num> Retry request if transient problems occur
# --retry-all-errors Retry all errors (use with --retry)
# --retry-connrefused Retry on connection refused (use with --re
# --retry-delay <seconds> Wait time between retries
# --retry-max-time <seconds> Retry only within this period
# --sasl-authzid <identity> Identity for SASL PLAIN authenticatio
# --sasl-ir Enable initial response in SASL authentica
# --service-name <name> SPNEGO service name
# -S, --show-error Show error even when -s is used
# -s, --silent Silent mode
# --socks4 <host[:port]> SOCKS4 proxy on given host + port
# --socks4a <host[:port]> SOCKS4a proxy on given host + port
# --socks5 <host[:port]> SOCKS5 proxy on given host + port
# --socks5-basic Enable username/password auth for SOCKS5 p
# --socks5-gssapi Enable GSS-API auth for SOCKS5 proxies
# --socks5-gssapi-nec Compatibility with NEC SOCKS5 server
# --socks5-gssapi-service <name> SOCKS5 proxy service name for GS
# --socks5-hostname <host[:port]> SOCKS5 proxy, pass host name to
# -Y, --speed-limit <speed> Stop transfers slower than this
# -y, --speed-time <seconds> Trigger 'speed-limit' abort after this t
# --ssl Try SSL/TLS
# --ssl-allow-beast Allow security flaw to improve interop
# --ssl-auto-client-cert Use auto client certificate (Schannel)
# --ssl-no-revoke Disable cert revocation checks (Schannel)
# --ssl-reqd Require SSL/TLS
# --ssl-revoke-best-effort Ignore missing/offline cert CRL dist p
# -2, --sslv2 Use SSLv2
# -3, --sslv3 Use SSLv3
# --stderr <file> Where to redirect stderr
# --styled-output Enable styled output for HTTP headers
# --suppress-connect-headers Suppress proxy CONNECT response head
# --tcp-fastopen Use TCP Fast Open
# --tcp-nodelay Use the TCP_NODELAY option
# -t, --telnet-option <opt=val> Set telnet option
# --tftp-blksize <value> Set TFTP BLKSIZE option
# --tftp-no-options Do not send any TFTP options
# -z, --time-cond <time> Transfer based on a time condition
# --tls-max <VERSION> Set maximum allowed TLS version
# --tls13-ciphers <ciphersuite list> TLS 1.3 cipher suites to use
# --tlsauthtype <type> TLS authentication type
# --tlspassword <string> TLS password
# --tlsuser <name> TLS user name
# -1, --tlsv1 Use TLSv1.0 or greater
# --tlsv1.0 Use TLSv1.0 or greater
# --tlsv1.1 Use TLSv1.1 or greater
# --tlsv1.2 Use TLSv1.2 or greater
# --tlsv1.3 Use TLSv1.3 or greater
# --tr-encoding Request compressed transfer encoding
# --trace <file> Write a debug trace to FILE
# --trace-ascii <file> Like --trace, but without hex output
# --trace-time Add time stamps to trace/verbose output
# --unix-socket <path> Connect through this Unix domain socket
# -T, --upload-file <file> Transfer local FILE to destination
# --url <url> URL to work with
# -B, --use-ascii Use ASCII/text transfer
# -u, --user <user:password> Server user and password
# -A, --user-agent <name> Send User-Agent <name> to server
# -v, --verbose Make the operation more talkative
# -V, --version Show version number and quit
# -w, --write-out <format> Use output FORMAT after completion
# --xattr Store metadata in extended file attributes
Tip: Click below image to open 5k+ manual pages of curl.
