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简介
正常来说，我们访问一个接口或者链接的时候，经常会用这样的几种方式：
- 浏览器访问
- http工具访问(postman/idea的http client等)
- curl(使用命令行的方式来访问)
cURL是一个利用URL语法在命令行下工作的文件传输工具，1997年首次发行。它支持文件上传和下载，所以是综合传输工具，但按传统，习惯称cURL为下载工具。cURL还包含了用于程序开发的libcurl。
写这篇文章的初衷，主要来源于很多线上联调的接口，限制了ip白名单，需要上到具体的服务器访问，但是，每次记得住的只有 curl 'http://xxxx',，还要每次去百度对应的参数意思。这样要是同事在身边，我没法装起来。赶紧记录一波。
先来一波总结图(来自知乎)
开始使用
curl也是linux系统的一个指令，我们可以通过help查看参数(完整的在附录1)
请求就是命令以及参数的组合，下面就是一个很简单的一个请求
# -v 表示显示完整的请求和响应内容
curl -v 'www.baidu.com'
# 返回内容
* Rebuilt URL to: www.baidu.com/
* Trying 103.235.46.39...
* Connected to www.baidu.com (103.235.46.39) port 80 (#0)
> GET / HTTP/1.1
> Host: www.baidu.com
> User-Agent: curl/7.47.0
> Accept: */*
>
# 以上为请求内容，留意箭头为 >
# 以下为响应内容，箭头是 <
< 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: Sun, 13 Jun 2021 17:15:41 GMT
< Etag: "588604ec-94d"
< Last-Modified: Mon, 23 Jan 2017 13:28:12 GMT
< Pragma: no-cache
< Server: bfe/1.0.8.18
< Set-Cookie: BDORZ=27315; max-age=86400; domain=.baidu.com; path=/
<
<!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&tpl=mn&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>©2017 Baidu <a href=http://www.baidu.com/duty/>使用百度前必读</a> <a href=http://jianyi.baidu.com/ class=cp-feedback>意见反馈</a> 京ICP证030173号 <img src=//www.baidu.com/img/gs.gif> </p> </div> </div> </div> </body> </html>
* Connection #0 to host www.baidu.com left intact
常用的参数
| 参数(大小写注意) | 加长写法 | 备注 |
|---|---|---|
| -X | --request | 请求的方式，如果没有指定，为GET |
| -d | --data | 请求参数，后面跟文字或者文件路径 如果需要urlencode，可以使用 --data-urlencode |
| -H | --header | 请求头(多个请求头用多次 -H) |
| -b | --cookie | 请求带上cookie，后面可以加文字或者文件路径 |
| -i | --include | 查看响应头 |
| -I | --head | 返回值只带响应头 |
| -v | --verbose | 输出详细的返回信息，一般用于debug |
| -O | --remote-name | 外部文件输出到文件 |
| -o | --output | 输出到文件 |
| -u | --user | 账号密码 USER[:PASSWORD] |
可能用到的一些指令
## 发出get 请求
curl 'http://127.0.0.1:8080/user'
## 发出post json格式
curl -v -X POST -H "Content-Type: application/json" http://127.0.0.1:8080/user -d'{"username":"admin","password":"admin1234"}'
## 发出post x-www-form-urlencoded
curl -v -X POST --data-urlencode 'key1=value1&key2=value2' http://127.0.0.1:8080/user
## curl认证
curl -u user:pwd URL
记住上面的应该就可以满足日常使(zhuang)用(B)了
总结
curl是一个linux的一个命令，用于在linux机器中请求或者访问网址，后可以跟参数来满足我们不同需求。
在浏览器中的请求，我们也可以复制为curl的格式。
在idea的Http Client工具中，也支持将curl的格式转换为对应的格式请求。
附录
1. 参考文章
2. 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-status Verify the status of the server certificate (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 Read config from FILE
--connect-timeout SECONDS Maximum time allowed for connection
-C, --continue-at OFFSET Resumed transfer OFFSET
-b, --cookie STRING/FILE Read cookies from STRING/FILE (H)
-c, --cookie-jar FILE Write cookies to 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-raw DATA HTTP POST data, '@' allowed (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)
--dns-servers DNS server addrs to use: 1.1.1.1;2.2.2.2
--dns-interface Interface to use for DNS requests
--dns-ipv4-addr IPv4 address to use for DNS requests, dot notation
--dns-ipv6-addr IPv6 address to use for DNS requests, dot notation
-D, --dump-header FILE Write the headers to FILE
--egd-file FILE EGD socket path for random data (SSL)
--engine ENGINE Crypto engine (use "--engine list" for list) (SSL)
--expect100-timeout SECONDS How long to wait for 100-continue (H)
-f, --fail Fail silently (no output at all) on HTTP errors (H)
--false-start Enable TLS False Start.
-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 Pass custom header LINE 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)
--http1.1 Use HTTP 1.1 (H)
--http2 Use HTTP 2 (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 Use network INTERFACE (or address)
-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 Wait SECONDS 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 security LEVEL (F)
--libcurl FILE Dump libcurl equivalent code of this command line
--limit-rate RATE Limit transfer speed to RATE
-l, --list-only List only mode (F/POP3)
--local-port RANGE Force use of RANGE for local port numbers
-L, --location Follow redirects (H)
--location-trusted Like '--location', and send auth to other hosts (H)
--login-options OPTIONS Server login options (IMAP, POP3, SMTP)
-M, --manual Display the full manual
--mail-from FROM Mail from this address (SMTP)
--mail-rcpt TO Mail to this/these addresses (SMTP)
--mail-auth AUTH Originator address of the original email (SMTP)
--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 (SPNEGO) authentication (H)
-n, --netrc Must read .netrc for user name and password
--netrc-optional Use either .netrc or URL; overrides -n
--netrc-file FILE Specify FILE for netrc
-:, --next Allows the following URL to use a separate set of options
--no-alpn Disable the ALPN TLS extension (H)
-N, --no-buffer Disable buffering of the output stream
--no-keepalive Disable keepalive use on the connection
--no-npn Disable the NPN TLS extension (H)
--no-sessionid Disable SSL session-ID reusing (SSL)
--noproxy List of hosts which do not use proxy
--ntlm Use HTTP NTLM authentication (H)
--oauth2-bearer TOKEN OAuth 2 Bearer Token (IMAP, POP3, SMTP)
-o, --output FILE Write to FILE instead of stdout
--pass PASS Pass phrase for the private key (SSL/SSH)
--path-as-is Do not squash .. sequences in URL path
--pinnedpubkey FILE/HASHES Public key to verify peer against (SSL)
--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 PROTOCOLS
--proto-default PROTOCOL Use PROTOCOL for any URL missing a scheme
--proto-redir PROTOCOLS Enable/disable 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 HTTP Negotiate (SPNEGO) authentication on the proxy (H)
--proxy-ntlm Use NTLM authentication on the proxy (H)
--proxy-service-name NAME SPNEGO proxy service name
--service-name NAME SPNEGO service name
-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 RANGE
--raw Do HTTP "raw"; no 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 Wait SECONDS between retries
--retry-max-time SECONDS Retry only within this period
--sasl-ir Enable initial response in SASL authentication
-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 GSS-API
--socks5-gssapi-nec Compatibility with NEC SOCKS5 server
-Y, --speed-limit RATE Stop transfers below RATE for 'speed-time' secs
-y, --speed-time SECONDS Trigger 'speed-limit' abort after SECONDS (default: 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)
--ssl-no-revoke Disable cert revocation checks (WinSSL)
--stderr FILE Where to redirect stderr (use "-" for 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 FILE
--trace-ascii FILE Like --trace, but without 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 Send User-Agent STRING to server (H)
-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
-q Disable .curlrc (must be first parameter)
