curl 是⼀种命令⾏⼯具，作⽤是发出⽹络请求，然后获取数据，显⽰在\"标准输出\"（stdout）上⾯。它⽀持多种协议，下⾯列举其常⽤功能。

⼀、查看⽹页源码

$ curl www.sina.com

如果要把这个⽹页保存下来，可以使⽤ -o 参数：

$ curl -o [⽂件名] www.sina.com

⼆、⾃动跳转

有的⽹址是⾃动跳转的。使⽤ -L 参数，curl 就会跳转到新的⽹址。

$ curl -L www.sina.com

三、显⽰头信息

-i 参数可以显⽰ http response 的头信息，连同⽹页代码⼀起。-I 参数则只显⽰ http response 的头信息。

$ curl -i www.sina.com

HTTP/1.1 301 Moved PermanentlyServer: nginx

Date: Tue, 23 Aug 2016 08:30:16 GMTContent-Type: text/html

Location: http://www.sina.com.cn/

Expires: Tue, 23 Aug 2016 08:32:16 GMTCache-Control: max-age=120Age: 102

Content-Length: 178

X-Cache: HIT from xd33-83.sina.com.cn

四、显⽰通信过程

-v 参数可以显⽰⼀次 http 通信的整个过程，包括端⼝连接和 http request 头信息。

$ curl -v www.sina.com

* Rebuilt URL to: www.sina.com/

* Hostname was NOT found in DNS cache* Trying 202.108.33.60...

* Connected to www.sina.com (202.108.33.60) port 80 (#0)> GET / HTTP/1.1

> User-Agent: curl/7.35.0> Host: www.sina.com> Accept: */*>

< HTTP/1.1 301 Moved Permanently* Server nginx is not blacklisted< Server: nginx

< Date: Tue, 23 Aug 2016 08:48:14 GMT

< Content-Type: text/html

< Location: http://www.sina.com.cn/

< Expires: Tue, 23 Aug 2016 08:50:14 GMT< Cache-Control: max-age=120< Age: 40

< Content-Length: 178

< X-Cache: HIT from xd33-81.sina.com.cn<

* Connection #0 to host www.sina.com left intact

如果觉得上⾯的信息还不够，那么下⾯的命令可以查看更详细的通信过程。

$ curl --trace output.txt www.sina.com

或者

$ curl --trace-ascii output.txt www.sina.com

运⾏后，打开 output.txt ⽂件查看。

五、发送表单信息

发送表单信息有 GET 和 POST 两种⽅法。GET ⽅法相对简单，只要把数据附在⽹址后⾯就⾏。

$ curl example.com/form.cgi?data=xxx

POST ⽅法必须把数据和⽹址分开，curl 就要⽤到 --data 或者 -d 参数。

$ curl -X POST --data \"data=xxx\" example.com/form.cgi

如果你的数据没有经过表单编码，还可以让 curl 为你编码，参数是 --data-urlencode 。

$ curl -X POST--data-urlencode \"date=April 1\" example.com/form.cgi

六、HTTP动词

curl 默认的 HTTP 动词是 GET，使⽤ -X 参数可以⽀持其他动词。

$ curl -X POST www.example.com$ curl -X DELETE www.example.com

七、User Agent字段

这个字段是⽤来表⽰客户端的设备信息。服务器有时会根据这个字段，针对不同设备，返回不同格式的⽹页，⽐如⼿机版和桌⾯版。 浏览器的 User Agent 是：

Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.84 Safari/537.36

curl 可以这样模拟：

$ curl --user-agent \"[User Agent]\" [URL]

⼋、cookie

使⽤ --cookie 参数，可以让 curl 发送 cookie。

$ curl --cookie \"name=xxx\" www.example.com

⾄于具体的 cookie 的值，可以从 http response 头信息的 Set-Cookie 字段中得到。

九、增加头信息

有时需要在 http request 之中，⾃⾏增加⼀个头信息。 --header 参数就可以起到这个作⽤。

$ curl --header \"Content-Type:application/json\" http://example.com

⼗、HTTP认证

有些⽹域需要 HTTP 认证，这时 curl 需要⽤到 --user 或者 -u 参数。

$ curl --user name:password example.com

附录 curl 命令完整的参数

Options: (H) means HTTP/HTTPS only, (F) means FTP only --anyauth Pick \"any\" authentication method (H)

-a, --append Append to target file when uploading (F/SFTP) --basic Use HTTP Basic Authentication (H)

--cacert FILE CA certificate to verify peer against (SSL) --capath DIR CA directory to verify peer against (SSL)

-E, --cert CERT[:PASSWD] Client certificate file and password (SSL) --cert-type TYPE Certificate file type (DER/PEM/ENG) (SSL) --ciphers LIST SSL ciphers to use (SSL)

--compressed Request compressed response (using deflate or gzip) -K, --config FILE Specify which config file to read

--connect-timeout SECONDS Maximum time allowed for connection -C, --continue-at OFFSET Resumed transfer offset

-b, --cookie STRING/FILE String or file to read cookies from (H) -c, --cookie-jar FILE Write cookies to this file after operation (H) --create-dirs Create necessary local directory hierarchy --crlf Convert LF to CRLF in upload

--crlfile FILE Get a CRL list in PEM format from the given file -d, --data DATA HTTP POST data (H)

--data-ascii DATA HTTP POST ASCII data (H) --data-binary DATA HTTP POST binary data (H)

--data-urlencode DATA HTTP POST data url encoded (H) --delegation STRING GSS-API delegation permission --digest Use HTTP Digest Authentication (H) --disable-eprt Inhibit using EPRT or LPRT (F) --disable-epsv Inhibit using EPSV (F)

-D, --dump-header FILE Write the headers to this file

--egd-file FILE EGD socket path for random data (SSL)

--engine ENGINGE Crypto engine (SSL). \"--engine list\" for list -f, --fail Fail silently (no output at all) on HTTP errors (H) -F, --form CONTENT Specify HTTP multipart POST data (H) --form-string STRING Specify HTTP multipart POST data (H) --ftp-account DATA Account data string (F)

--ftp-alternative-to-user COMMAND String to replace \"USER [name]\" (F) --ftp-create-dirs Create the remote dirs if not present (F)

--ftp-method [MULTICWD/NOCWD/SINGLECWD] Control CWD usage (F) --ftp-pasv Use PASV/EPSV instead of PORT (F)

-P, --ftp-port ADR Use PORT with given address instead of PASV (F) --ftp-skip-pasv-ip Skip the IP address for PASV (F) --ftp-pret Send PRET before PASV (for drftpd) (F) --ftp-ssl-ccc Send CCC after authenticating (F)

--ftp-ssl-ccc-mode ACTIVE/PASSIVE Set CCC mode (F)

--ftp-ssl-control Require SSL/TLS for ftp login, clear for transfer (F)-G, --get Send the -d data with a HTTP GET (H)

-g, --globoff Disable URL sequences and ranges using {} and []-H, --header LINE Custom header to pass to server (H)-I, --head Show document info only-h, --help This help text

--hostpubmd5 MD5 Hex encoded MD5 string of the host public key. (SSH)-0, --http1.0 Use HTTP 1.0 (H)

--ignore-content-length Ignore the HTTP Content-Length header-i, --include Include protocol headers in the output (H/F)

-k, --insecure Allow connections to SSL sites without certs (H) --interface INTERFACE Specify network interface/address to use-4, --ipv4 Resolve name to IPv4 address-6, --ipv6 Resolve name to IPv6 address

-j, --junk-session-cookies Ignore session cookies read from file (H)

--keepalive-time SECONDS Interval between keepalive probes --key KEY Private key file name (SSL/SSH)

--key-type TYPE Private key file type (DER/PEM/ENG) (SSL) --krb LEVEL Enable Kerberos with specified security level (F) --libcurl FILE Dump libcurl equivalent code of this command line --limit-rate RATE Limit transfer speed to this rate-l, --list-only List only names of an FTP directory (F)

--local-port RANGE Force use of these local port numbers-L, --location Follow redirects (H)

--location-trusted like --location and send auth to other hosts (H)-M, --manual Display the full manual --mail-from FROM Mail from this address --mail-rcpt TO Mail to this receiver(s)

--mail-auth AUTH Originator address of the original email --max-filesize BYTES Maximum file size to download (H/F) --max-redirs NUM Maximum number of redirects allowed (H)-m, --max-time SECONDS Maximum time allowed for the transfer --metalink Process given URLs as metalink XML file --negotiate Use HTTP Negotiate Authentication (H)-n, --netrc Must read .netrc for user name and password --netrc-optional Use either .netrc or URL; overrides -n --netrc-file FILE Set up the netrc filename to use-N, --no-buffer Disable buffering of the output stream --no-keepalive Disable keepalive use on the connection --no-sessionid Disable SSL session-ID reusing (SSL) --noproxy List of hosts which do not use proxy --ntlm Use HTTP NTLM authentication (H)

-o, --output FILE Write output to instead of stdout

--pass PASS Pass phrase for the private key (SSL/SSH)

--post301 Do not switch to GET after following a 301 redirect (H) --post302 Do not switch to GET after following a 302 redirect (H) --post303 Do not switch to GET after following a 303 redirect (H)-#, --progress-bar Display transfer progress as a progress bar --proto PROTOCOLS Enable/disable specified protocols

--proto-redir PROTOCOLS Enable/disable specified protocols on redirect-x, --proxy [PROTOCOL://]HOST[:PORT] Use proxy on given port --proxy-anyauth Pick \"any\" proxy authentication method (H) --proxy-basic Use Basic authentication on the proxy (H) --proxy-digest Use Digest authentication on the proxy (H)

--proxy-negotiate Use Negotiate authentication on the proxy (H) --proxy-ntlm Use NTLM authentication on the proxy (H)-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 a HTTP proxy tunnel (using CONNECT) --pubkey KEY Public key file name (SSH)

-Q, --quote CMD Send command(s) to server before transfer (F/SFTP) --random-file FILE File for reading random data from (SSL)-r, --range RANGE Retrieve only the bytes within a range

--raw Do HTTP \"raw\", without any transfer decoding (H)-e, --referer Referer URL (H)

-J, --remote-header-name Use the header-provided filename (H)-O, --remote-name Write output to a file named as the remote file --remote-name-all Use the remote file name for all URLs-R, --remote-time Set the remote file's time on the local output-X, --request COMMAND Specify request command to use

--resolve HOST:PORT:ADDRESS Force resolve of HOST:PORT to ADDRESS --retry NUM Retry request NUM times if transient problems occur

--retry-delay SECONDS When retrying, wait this many seconds between each --retry-max-time SECONDS Retry only within this period

-S, --show-error Show error. With -s, make curl show errors when they occur-s, --silent Silent mode. Don't output anything

--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 proxies --socks5-gssapi Enable GSS-API auth for SOCKS5 proxies

--socks5-hostname HOST[:PORT] SOCKS5 proxy, pass host name to proxy --socks5-gssapi-service NAME SOCKS5 proxy service name for gssapi --socks5-gssapi-nec Compatibility with NEC SOCKS5 server

-Y, --speed-limit RATE Stop transfers below speed-limit for 'speed-time' secs-y, --speed-time SECONDS Time for trig speed-limit abort. Defaults to 30 --ssl Try SSL/TLS (FTP, IMAP, POP3, SMTP)

--ssl-reqd Require SSL/TLS (FTP, IMAP, POP3, SMTP)-2, --sslv2 Use SSLv2 (SSL)-3, --sslv3 Use SSLv3 (SSL)

--ssl-allow-beast Allow security flaw to improve interop (SSL) --stderr FILE Where to redirect stderr. - means stdout --tcp-nodelay Use the TCP_NODELAY option-t, --telnet-option OPT=VAL Set telnet option

--tftp-blksize VALUE Set TFTP BLKSIZE option (must be >512)-z, --time-cond TIME Transfer based on a time condition-1, --tlsv1 Use => TLSv1 (SSL) --tlsv1.0 Use TLSv1.0 (SSL) --tlsv1.1 Use TLSv1.1 (SSL)

--tlsv1.2 Use TLSv1.2 (SSL)

--trace FILE Write a debug trace to the given file

--trace-ascii FILE Like --trace but without the hex output --trace-time Add time stamps to trace/verbose output --tr-encoding Request compressed transfer encoding (H)-T, --upload-file FILE Transfer FILE to destination --url URL URL to work with

-B, --use-ascii Use ASCII/text transfer

-u, --user USER[:PASSWORD] Server user and password --tlsuser USER TLS username

--tlspassword STRING TLS password

--tlsauthtype STRING TLS authentication type (default SRP) --unix-socket FILE Connect through this UNIX domain socket-A, --user-agent STRING User-Agent to send to server (H)-v, --verbose Make the operation more talkative-V, --version Show version number and quit

-w, --write-out FORMAT What to output after completion --xattr Store metadata in extended file attributes-q If used as the first parameter disables .curlrc