Introduction and comparison of the curl and wget commands in Linux

This article covers the curl and wget commands in Linux, both of which are tools for downloading files. Here's a look at the details:

1. wget

wget is the most commonly used download command for linux. The 1-like usage is: wget + space + url path to download the file

Case 1:

wget http://www.minjieren.com/wordpress-3.1-zh_CN.zip

Download the file and save it to the current directory. The default file name is url last/last, wordpress-3.1-zh_CN.zip

Example 2:

wget -O myfile http://www.minjieren.com/wordpress-3.1-zh_CN.zip

You can specify the file name with the -O parameter, which in this case is myfile

Example 3:

wget www.baidu.com

An index.html file is generated in the current directory

2. curl

In Linux, curl is a file transfer tool that USES URL rules to work under the command line. It is a very powerful http command line tool. It supports the upload and download of files, and is a comprehensive transfer tool, but traditionally, it is used to call url as the download tool.

Syntax: # curl [option] [url]

Common parameters:

-A/--user-agent < string > Set up the user agent to send to the server -b/--cookie < name=string/file > cookie string or file read location -c/--cookie-jar < file > Write cookie to this file at the end of the operation -C/--continue-at < offset > Breakpoint continued to turn -D/--dump-header < file > Write the header information to this file -e/--referer source url -f /--fail connection failure does not display http error -o /--output writes the output to this file -O /-- remote-name writes the output to the file, keeping the name of the remote file -r/--range < range > Retrieves the byte range from the HTTP/1.1 or FTP server -s /--silent mute mode. It doesn't export anything -T/--upload-file < file > Upload a file -u/--user < user[:password] > Set the user and password for the server -w /-- write-out [format] what output is completed -x/--proxy < host[:port] > Use the HTTP proxy on the given port -#/-- progress-bar progress bar shows the current transfer status

Ex. :

curl -O http://download.oracle.com/otn-pub/java/jdk/8u91-b14/jdk-8u91-linux-i586.tar.gz

Download files saved to the current directory, file name is the last one url by default/later, here is the jdk - 8 u91 - linux - i586. tar. gz.

Note: the -O parameter must be added, otherwise the file contents will be displayed directly on the console.

Note: these two command tools, linux system default not 1 must have, if not, you need to install their own. If it's under ubuntu.

The following command can be used for installation

sudo apt-get install curl

The differences are as follows:

1.curl is supported by the library libcurl, and wget is a pure command-line command.

2.curl supports more protocols. curl supports FTP, FTPS, HTTP, HTTPS, SCP, SFTP, TFTP, TELNET, DICT, LDAP, LDAPS, POP3, IMAP, SMTP and HTTPS the time this writing Wget supports HTTP HTTPS and FTP

3.curl supports HTTP1.1 (also 1.0) by default, while wget only supports HTTP1.0. To quote a passage from wget, man page,

Please be aware that Wget needs to know the size of the POST data in advance. It's not quite clear how to work around this limitation inherent in HTTP/1.0. Although HTTP/1.1 introduces chunked transfer that doesn't require knowing the request length in advance, a client can't use chunked unless it knows it's talking to an HTTP/1.1 server. And it can't know that until it receives a response, which in turn requires the request to have been completed -- a chicken-and-egg problem.

4.curl can support a sequence or collection of URL when specifying a link to download, whereas wget cannot;

5.wget supports recursive downloads, while curl does not. (this is one of the main benefits of wget. wget also has advantages.)

conclusion