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How to Download a File Using cURL With Examplesby@trubavuong
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How to Download a File Using cURL With Examples

by Vuong TruJuly 20th, 2020
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Using cURL to retrieve the output of a file only takes a few more characters. Saving a file with a remote file name can save the output to a local file in the current working directory. Using the output redirection operator in Linux, you can use the output append operator to write the output into a specific file. If the target server responded with the HTTP redirection code (3xx) for the requested file, the local file you downloaded would be empty. If you want to download multiple files with a single command, you have to add the sizeof-r to the cURL.

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If you have ever used cURL to retrieve the output of a file, believe me, saving that output to a file only takes a few more characters.

Example #1: Saving a file with the remote file name

You can use the 

-O
 or 
--remote-name
 option to save the output to a local file in the current working directory using the remote file name.

$ curl -O https://example.com/files/README

In this example, the 

./README
 file will be created or overwritten.

Example #2: Saving a file with another file name

You can use the 

-o
 or 
--output
 option followed by a file name you want to save the output.

$ curl -o my-readme-file       https://example.com/files/README
$ curl -o ~/save/to/other/path https://example.com/files/README

Similar to the above example, the output file will be created or overwritten.

Example #3: Saving a file using the output redirection operator

In Linux, you can use the output redirection operator 

>
 to write the output to a specific file.

$ curl https://example.com/files/README > ~/save/to/specific/path

If you want to append the output to that file, you can use the output append operator 

>>
 instead.

Example #4: Downloading multiple files with a single command

If you want to download multiple files, you can add more 

-o
 or 
-O 
options:

$ curl \
  -O https://example.com/files/file-1 \
  -o file-2 https://example.com/files/file-2 \
  -o file-3 https://example.com/files/file-3

Example #5: Dealing with the HTTP redirection

If the target server responded with the HTTP redirection code (3xx) for the requested file, the local file you downloaded would be empty. In this case, you have to add the 

-L
 or 
--location
 option to tell cURL to follow the redirects.

$ curl -L -O https://example.com/files/README

You can use the 

--max-redirs <number>
 option to specify the maximum number of redirects will be followed to avoid infinite redirection-followings:

$ curl -L --max-redirs 10 -O https://example.com/files/README

In this example, after 10 attempts, cURL will throw an error and abort the download process.

Example #6: Speed limiting

If you want to limit the downloading speed, you can use the 

--limit-rate <speed>
 option to set the maximum number of bytes downloaded per second. The number of bytes can be abbreviated by appending a suffix: kilobytes (k or K), megabytes (m or M), and gigabytes (g or G).

To limit 512 bytes/second and 2 megabytes/second:

$ curl --limit-rate 512 -O https://example.com/files/README
$ curl --limit-rate  2M -O https://example.com/files/README

Example #7: Downloading a part of a file

cURL allows you to download a part of a file by using the 

-r <range>
 or 
--range <range>
 option.

For example, to get the first 500 bytes of a file:

$ curl -r 0-500 -O https://example.com/files/README

To get the last 300 bytes of a file:

$ curl -r -300 -O https://example.com/files/README

Example #8: Resuming downloading a file

What would you do if the download process was interrupted, for example, you pressed 

Ctrl + C
? Re-download?

Do not! Because cURL supports resuming a file downloading process at the given offset by the 

-C <offset>
 option. If you do not know the exact value of the offset, do not worry, you just need to specify 
-C -
 to tell cURL to automatically find out that value.

$ curl -C - -O https://example.com/files/README

Example #9: Using basic authentication

If the requested file requires basic authentication, you need to use the 

-u
 option followed by the credential which is in the form of 
user:password
:

$ curl -u user:password -O https://example.com/files/README

To read more about basic authentication, you can read the article 3 methods to use basic authentication with cURL.

Example #10: Using a proxy

If you want to use a proxy to download a file, you need to use 

-x
 option followed by the proxy address, say 
http://111.111.111.111:8080
:

$ curl -x http://111.111.111.111:8080 -O https://example.com/files/README

To see more examples, you can read the article How to use a proxy with cURL.

Example #11: Entering the silent mode

If you do not want cURL to show the progress meter or error messages, you can use the 

-s
 or 
--silent
 option:

$ curl -s -O https://example.com/files/README

Previously published at https://trubavuong.com/articles/curl-download-file/