Linux系列之学会使用CURL命令

一. 查看帮助
- 1.1 查看命令参数
二. 查询使用手册
- 2.1 查看详细使用
三. 提取网页
四. 用curl进行认证
五. 文件操作
六. Cookie设置
七. curl RESTFul
八. CURL参考资料

curl命令是一个利用URL规则在shell终端命令行下工作的文件传输工具；curl命令作为一款强力工具，curl支持包括HTTP、HTTPS、ftp等众多协议，还支持POST、cookies、认证、从指定偏移处下载部分文件、用户代理字符串、限速、文件大小、进度条等特征；做网页处理流程和数据检索自动化。

语法：语法格式：curl [参数] [网址]

一. 查看帮助

1.1 查看命令参数

curl的参数很多，可以用命令curl --help查看：

[root@localhost ~]# curl --help

Usage: curl [options...] <url>

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 <file> 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-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)

 -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

国内翻译过来的curl文档：curl参数介绍

二. 查询使用手册

2.1 查看详细使用

也可以使用curl --manual查看基本用法例子：

三. 提取网页

3.1 查看网页源码

语法：curl uri

[root@localhost ~]# curl www.baidu.com

<!DOCTYPE html>

<!--STATUS OK--><html> <head><meta http-equiv=content-type content=text/html;charset=utf-8><meta http-equiv=X-UA-Compatible content=IE=Edge><meta content=always name=referrer><link rel=stylesheet type=text/css href=http://s1.bdstatic.com/r/www/cache/bdorz/baidu.min.css><title>百度一下，你就知道</title></head> <body link=#0000cc> <div id=wrapper> <div id=head> <div class=head_wrapper> <div class=s_form> <div class=s_form_wrapper> <div id=lg> <img hidefocus=true src=//www.baidu.com/img/bd_logo1.png width=270 height=129> </div> <form id=form name=f action=//www.baidu.com/s class=fm> <input type=hidden name=bdorz_come value=1> <input type=hidden name=ie value=utf-8> <input type=hidden name=f value=8> <input type=hidden name=rsv_bp value=1> <input type=hidden name=rsv_idx value=1> <input type=hidden name=tn value=baidu><span class="bg s_ipt_wr"><input id=kw name=wd class=s_ipt value maxlength=255 autocomplete=off autofocus></span><span class="bg s_btn_wr"><input type=submit id=su value=百度一下 class="bg s_btn"></span> </form> </div> </div> <div id=u1> <a href=http://news.baidu.com name=tj_trnews class=mnav>新闻</a> <a href=http://www.hao123.com name=tj_trhao123 class=mnav>hao123</a> <a href=http://map.baidu.com name=tj_trmap class=mnav>地图</a> <a href=http://v.baidu.com name=tj_trvideo class=mnav>视频</a> <a href=http://tieba.baidu.com name=tj_trtieba class=mnav>贴吧</a> <noscript> <a href=http://www.baidu.com/bdorz/login.gif?login&amp;tpl=mn&amp;u=http%3A%2F%2Fwww.baidu.com%2f%3fbdorz_come%3d1 name=tj_login class=lb>登录</a> </noscript> <script>document.write('<a href="http://www.baidu.com/bdorz/login.gif?login&tpl=mn&u='+ encodeURIComponent(window.location.href+ (window.location.search === "" ? "?" : "&")+ "bdorz_come=1")+ '" name="tj_login" class="lb">登录</a>');</script> <a href=//www.baidu.com/more/ name=tj_briicon class=bri style="display: block;">更多产品</a> </div> </div> </div> <div id=ftCon> <div id=ftConw> <p id=lh> <a href=http://home.baidu.com>关于百度</a> <a href=http://ir.baidu.com>About Baidu</a> </p> <p id=cp>&copy;2017&nbsp;Baidu&nbsp;<a href=http://www.baidu.com/duty/>使用百度前必读</a>&nbsp; <a href=http://jianyi.baidu.com/ class=cp-feedback>意见反馈</a>&nbsp;京ICP证030173号&nbsp; <img src=//www.baidu.com/img/gs.gif> </p> </div> </div> </div> </body> </html>

3.2 显示头信息

curl -i https://www.baidu.com

打印信息：

[root@localhost ~]# curl -i https://www.baiud.com

curl: (7) Failed connect to www.baiud.com:443; Connection refused

[root@localhost ~]# curl -i https://www.baidu.com

HTTP/1.1 200 OK

Accept-Ranges: bytes

Cache-Control: private, no-cache, no-store, proxy-revalidate, no-transform

Connection: keep-alive

Content-Length: 2443

Content-Type: text/html

Date: Mon, 13 Jul 2020 07:22:02 GMT

Etag: "588603eb-98b"

Last-Modified: Mon, 23 Jan 2017 13:23:55 GMT

Pragma: no-cache

Server: bfe/1.0.8.18

Set-Cookie: BDORZ=27315; max-age=86400; domain=.baidu.com; path=/

...

3.3 显示通信过程

curl -v www.baidu.com

curl -v www.baidu.com

* About to connect() to www.baidu.com port 80 (#0)

*   Trying 182.61.200.7...

* Connected to www.baidu.com (182.61.200.7) port 80 (#0)

> GET / HTTP/1.1

> User-Agent: curl/7.29.0

> Host: www.baidu.com

> Accept: */*

>

< HTTP/1.1 200 OK

< Accept-Ranges: bytes

< Cache-Control: private, no-cache, no-store, proxy-revalidate, no-transform

< Connection: keep-alive

< Content-Length: 2381

< Content-Type: text/html

< Date: Mon, 13 Jul 2020 07:24:46 GMT

< Etag: "588604c8-94d"

< Last-Modified: Mon, 23 Jan 2017 13:27:36 GMT

< Pragma: no-cache

< Server: bfe/1.0.8.18

< Set-Cookie: BDORZ=27315; max-age=86400; domain=.baidu.com; path=/

<

<!DOCTYPE html>

...

3.4 查看议定书

[root@localhost ~]# curl --trace-ascii output.txt https://www.baidu.com

3.5 查看时间

curl --trace-ascii output.txt --trace-time https://www.baidu.com

四. 用curl进行认证

4.1 referer设置

referer参数描述了一个网页的来源，可以按F12调试模式，查看：

访问百度时候，加上referer为csdn：

[root@localhost ~]# curl --referer https://blog.csdn.net https://www.baidu.com

4.2 用户代理设置

用户代理常被用于兼容ie，有时，您会看到获取带有curl的页面不会返回与使用浏览器获取页面时看到的页面相同的页面，这时候可以设置用户代理：

curl www.baidu.com --user-agent "Mozilla/5.0"

curl www.baidu.com -A "Mozilla/5.0"

4.3 用户信息校验

比如登录百度，可以用-u参数，接着会提示输入密码

[root@localhost ~]# curl -u admin https://www.baidu.net/

Enter host password for user 'admin':

五. 文件操作

5.1 保存文件

语法：curl -o filename uri

[root@localhost ~]# curl -o baidu.html www.baidu.com

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current

                                 Dload  Upload   Total   Spent    Left  Speed

100  2381  100  2381    0     0  22761      0 --:--:-- --:--:-- --:--:-- 22894

5.2 文件下载

语法：curl uri filename --silent|progress

--silent：不显示进度条
--progress：显示进度条

[root@localhost ~]# curl https://avatar.csdnimg.cn/3/5/E/1_meituantech_1564971608.jpg -omeituan.jpg --progress

######################################################################## 100.0%

5.3 上传文件

语法：　　$ curl --form upload=@localfilename --form press=OK [URL]

[root@localhost ~]# curl --form upload=@baidu.html --form press=OK url

六. Cookie设置

6.1 设置cookie

设置cookie，可以用命令--cookie

6.2 cookie -b -c

-c cookie-file可以保存服务器返回的cookie到文件，-b cookie-file可以使用这个文件作为cookie信息，进行后续的请求。

$ curl -c cookies http://example.com

$ curl -b cookies http://example.com

[root@localhost ~]# curl -c "name=cookiename" www.baidu.com

6.3 指定cookie文件

也可以用--cookie-jar指定cookie文件

[root@localhost ~]# curl www.baidu.com --cookie-jar cookie_file

指定可下载的最大文件大小，可以用命令--limit-rate

[root@localhost ~]# curl www.baidu.com --limit-rate 50k

七. curl RESTFul

7.1 RESTFul API

curl支持RESTFul API格式的，所以先补充一些RESTFul API知识：

GET 请求：获取服务器中的对象
- 相当于SQL的Select命令
- GET /blogs：列出所有博客信息
POST 请求：在服务器上新增对象
- 相当于SQL的Update命令
- POST /blogs/ID：新增指定的博客信息
PUT 请求：在服务器上更新对象
- 相当于SQL的Create命令
- PUT /blogs/ID：更新一个博客信息　　
DELETE 请求：删除服务器中的对象
- 相当于SQL的Delete命令
- DELETE /blogs/ID：删除指定的博客
HEAD 请求：仅仅用于获取对象的基础信息

7.2 POST请求

ps：-H指定请求header，-d指定参数

CURL POST：

[root@localhost ~]# curl -H "Content-Type:application/json" -X POST localhost:9200/company/employees/1 -d '{"id" :1,"name":"admin","password":"123"}'

7.3 GET请求

CURL GET：

[root@localhost ~]# curl -X GET localhost:9200/company/employees/1?pretty=true

7.4 DELETE请求

CURL DELETE：

[root@localhost ~]# curl -X DELETE localhost:9200/company/employees/1

7.5 PUT请求

CURL PUT：

curl -H "Content-Type:application/json" -X PUT localhost:9200/company/employees/1 -d '{"id" :1,"name":"admin","password":"111"}'

curl默认是GET方式请求url的，要调POST等接口，必须加上-X参数指定

八. CURL参考资料

CURL 官网教程：https://curl.haxx.se/docs/httpscripting.html

阮一峰老师教程：http://www.ruanyifeng.com/blog/2011/09/curl.html