linux命令每日学-curl

curl命令是一个功能强大的http命令行工具，在网站开发中能够帮助我们快速调试。下面总结下curl常用的功能。

1.发送请求

curl最基本的功能，输入要请求的url，会默认向该地址发送get请求并将返回值打印到终端上。如下所示：

1	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>鐧惧害涓€涓嬶紝浣犲氨鐭ラ亾</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=鐧惧害涓€涓?class="bg s_btn"></span> </form> </div> </div> <div id=u1> <a href=ht
tp://news.baidu.com name=tj_trnews class=mnav>鏂伴椈</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>鍦板浘</a> <a href=http://v.baidu.com name=tj_trvideo class=mnav>瑙嗛</a> <a href=http://t
ieba.baidu.com name=tj_trtieba class=mnav>璐村惂</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>鐧诲綍</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">鐧诲綍</a>');</script> <a href=//www.baidu.com/more/ name=tj_briicon class=bri style="display: block;">鏇村浜у搧</a> </div> </div> </div> <div id=ftCon> <div id=ftConw> <p id=lh> <a href=http://home.baidu.com>鍏充簬鐧惧害</a> <a hr
ef=http://ir.baidu.com>About Baidu</a> </p> <p id=cp>&copy;2017&nbsp;Baidu&nbsp;<a href=http://www.baidu.com/duty/>浣跨敤鐧惧害鍓嶅繀璇?/a>&nbsp; <a href=http://jianyi.baidu.com/ class=cp-feedback>鎰忚鍙嶉</a>&nbsp;浜琁CP璇?30173鍙?nbsp; <img src=//www.baidu.com/img/g
s.gif> </p> </div> </div> </div> </body> </html>
curl: (23) Failed writing body (2377 != 2381)

如果要将返回的数据保存下来可以使用-o参数

1	curl -o [文件名] www.baidu.com

2.显示返回头信息

使用-i参数可以显示response的头部信息

1	curl -i 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: 2381
Content-Type: text/html
Date: Sat, 24 Aug 2019 02:17:38 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>
<!--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>鐧惧害涓€涓嬶紝浣犲氨鐭ラ亾</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=鐧惧害涓€涓?class="bg s_btn"></span> </form> </div> </div> <div id=u1> <a href=ht
tp://news.baidu.com name=tj_trnews class=mnav>鏂伴椈</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>鍦板浘</a> <a href=http://v.baidu.com name=tj_trvideo class=mnav>瑙嗛</a> <a href=http://t
ieba.baidu.com name=tj_trtieba class=mnav>璐村惂</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>鐧诲綍</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">鐧诲綍</a>');</script> <a href=//www.baidu.com/more/ name=tj_briicon class=bri style="display: block;">鏇村浜у搧</a> </div> </div> </div> <div id=ftCon> <div id=ftConw> <p id=lh> <a href=http://home.baidu.com>鍏充簬鐧惧害</a> <a hr
ef=http://ir.baidu.com>About Baidu</a> </p> <p id=cp>&copy;2017&nbsp;Baidu&nbsp;<a href=http://www.baidu.com/duty/>浣跨敤鐧惧害鍓嶅繀璇?/a>&nbsp; <a href=http://jianyi.baidu.com/ class=cp-feedback>鎰忚鍙嶉</a>&nbsp;浜琁CP璇?30173鍙?nbsp; <img src=//www.baidu.com/img/g
s.gif> </p> </div> </div> </div> </body> </html>
curl: (23) Failed writing body (2377 != 2381)

3.显示完整的请求过程

使用-v参数可以显示本次请求的完整通信过程及request信息和response信息。

1	crul -v www.baidu.com

    Rebuilt URL to: www.baidu.com/
*   Trying 180.101.49.11...
* TCP_NODELAY set
* Connected to www.baidu.com (180.101.49.11) port 80 (#0)
> GET / HTTP/1.1
> Host: www.baidu.com
> User-Agent: curl/7.60.0
> 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: Sat, 24 Aug 2019 02:19:49 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>
<!--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>鐧惧害涓€涓嬶紝浣犲氨鐭ラ亾</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=鐧惧害涓€涓?class="bg s_btn"></span> </form> </div> </div> <div id=u1> <a href=ht
tp://news.baidu.com name=tj_trnews class=mnav>鏂伴椈</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>鍦板浘</a> <a href=http://v.baidu.com name=tj_trvideo class=mnav>瑙嗛</a> <a href=http://t
ieba.baidu.com name=tj_trtieba class=mnav>璐村惂</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>鐧诲綍</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">鐧诲綍</a>');</script> <a href=//www.baidu.com/more/ name=tj_briicon class=bri style="display: block;">鏇村浜у搧</a> </div> </div> </div> <div id=ftCon> <div id=ftConw> <p id=lh> <a href=http://home.baidu.com>鍏充簬鐧惧害</a> <a hr
ef=http://ir.baidu.com>About Baidu</a> </p> <p id=cp>&copy;2017&nbsp;Baidu&nbsp;<a href=http://www.baidu.com/duty/>浣跨敤鐧惧害鍓嶅繀璇?/a>&nbsp; <a href=http://jianyi.baidu.com/ class=cp-feedback>鎰忚鍙嶉</a>&nbsp;浜琁CP璇?30173鍙?nbsp; <img src=//www.baidu.com/img/g
s.gif> </p> </div> </div> </div> </body> </html>
* Failed writing body (2377 != 2381)
* stopped the pause stream!
* Closing connection 0
curl: (23) Failed writing body (2377 != 2381)

4.发送不同类型的请求

使用-X参数可以指定发送请求的类型

发送post请求

1	curl -X POST www.baidu.com

发送delete请求

1	curl -X DELETE www.baidu.com

5.发送表单数据

当使用post类型发送数据时需要用到–data参数，用来添加要发送的数据。

1	curl -X POST --data="xxx" www.baidu.com

curl还能都对数据进行表单编码

1	curl -X POST --data-urlencode="xxx" www.baidu.com

6.文件上传

使用curl进行文件上传

1	curl --form upload=@localfilename --form press=OK [URL]

7.referer字段

当你需要在http请求头中设置Referer字段时可以使用–referer参数

1	curl --referer http://www.example.com http://www.example.com

8.设置user-agent

当需要设置http请求头中的user-agent字段时可以使用–user-agent参数

1	curl --user-agent "[User Agent]" [URL]

9.设置cookie

当需要发送cookie请求时可以使用–cookie参数

1	curl --cookie "name=xxx" www.example.com

需要在header中添加自定义信息时可以使用–header参数

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

11.http认证

当遇到需要进行http认证的网站时可以使用–user参数

1	curl --user username/password www.baidu.com