Usage of Curl

Curl Usage Introduction

Curl is a command-line tool that interacts with the server (sending and retrieving information), supports Dict, FILE, FTP, FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, POP3, pop3s, RTMP, Protocols such as RTSP, SCP, SFTP, SMTP, SMTPS, Telnet, and TFTP. Curl supports functions such as proxy, user authentication, FTP upload, HTTP POST request, SSL connection, cookies, file transfer, Metalink, etc. URL

Curl supports URLs in several ways:

You can specify multiple URLs, or specify multiple parts of the URL in curly braces.

Http://site. {one,two,three}.com

You can specify a sequence of numbers or letters in brackets.

Ftp://ftp.numericals.com/file[1-100].txt
Ftp://ftp.numericals.com/file[001-100].txt    (with leading zeros)
Ftp://ftp.letters.com/file[a-z].txt

Multiple sequences can be specified.

Http://any.org/archive[1996-1999]/vol[1-4]/part{a,b,c}.html

You can specify any number of Url,curl on the command line to get the contents of the URL in the order specified.

You can specify the number of steps to jump within a range.

Http://www.numericals.com/file[1-100:10].txt
Http://www.letters.com/file[a-z:2].txt

If no protocol prefix is specified, curl attempts to guess the protocol. It chooses the HTTP protocol by default, but when it encounters a common host name, it chooses to try another protocol. For example, Ftp.xxx.com,curl will try the FTP protocol. View HTTP response Headers

Curl-i http://www.baidu.com

viewing the interaction process

Curl-v http://www.baidu.com

GET Request

When an HTTP request is initiated, Curl initiates a GET request by default, or it can be specified by the "-X GET" method.

Curl-x GET http://www.baidu.com

POST Request

When using the Post request method, you need to pass data to the server by specifying "-D".

Curl-x POST http://www.example.com/posts

Delete Request

Delete requests are used to remove server-side data.

Curl-x DELETE HTTP://WWW.EXAMPLE.COM/POSTS/1

put request

Put requests are used to modify server-side data

Curl-x PUT HTTP://WWW.EXAMPLE.COM/POSTS/1

HTTP Authentication

Common HTTP Authentication methods are: Basic certification, digest certification, OAUTH2 certification. Basic Certification

Curl--basic-  u user:password http://www.example.com/posts/1

Digest Certification

Curl--digest-u User:password HTTP://WWW.EXAMPLE.COM/POSTS/1

OAUTH2 Certification

Curl-u clientid:clientsecret-x post-d "Username=test&password=test&grant_type=password&scope=read" Http://www.example.com/oauth/token
curl-h "Authorization:bearer [Bearer]" HTTP://WWW.EXAMPLE.COM/POSTS/1

File Upload

Assume that the file uploads the form as follows:

<form method= "POST" enctype= ' Multipart/form-data ' action= "upload.cgi" >
    <input type=file name=upload >
    <input type=submit name=press value= "OK" >
</form>

You can use Curl to upload files as follows:

Curl--form upload= @localfilename--form press=ok http://www.example.com

User Agent Field

This field is used to represent the client's device information. The server sometimes returns pages of different formats, such as mobile and PC, based on this field, for different devices.

Curl--user-agent "[user agent]" http://www.example.com

Cookies

Curl can send cookies

Curl--cookie "Name1=value1" http://www.example.com

Download Web page

Curl-o file.html http://www.example.com

-o option to save files according to the server's file name

Curl-o http://www.example.com/1.jpg

Proxy Server

Curl-x Proxy server address: Port http://www.example.com

Save Cookie Information

curl-d Cookiefile01.txt http://www.example.com

Use files that store cookie information

curl-d cookiefile02.txt-b cookiefile01.txt http://www.example.com

output detailed interaction information

Curl http://www.example.com--trace-ascii/dev/stdout