The number of bytes can be abbreviated by appending a suffix: kilobytes k or K , megabytes m or M , and gigabytes g or G. Do not! 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.
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 :. To read more about basic authentication, you can read the article 3 methods to use basic authentication with cURL. Hacktoberfest Contribute to Open Source. Launch an Interactive Terminal! About the authors. Brian Hogan. Still looking for an answer?
Ask a question Search for more help. Comments Follow-Up Questions. Before you can do that To complete this action, sign in to your Community account or create a new one.
Because there is no terminal window output to display, curl outputs a set of progress information. In this example, curl detects that the output is being redirected to a file and that it is safe to generate the progress information. Double-clicking that file will open your default browser so that it displays the retrieved web page. Note that the address in the browser address bar is a local file on this computer, not a remote website. We can create a file by using the -o output option, and telling curl to create the file.
To have the text-based download information replaced by a simple progress bar, use the - progress bar option. It is easy to restart a download that has been terminated or interrupted. To restart the download, use the -C continue at option. This causes curl to restart the download at a specified point or offset within the target file. If you use a hyphen - as the offset, curl will look at the already downloaded portion of the file and determine the correct offset to use for itself.
Using xargs we can download multiple URLs at once. Perhaps we want to download a series of web pages that make up a single article or tutorial. This is the command we need to use to have xargs pass these URLs to curl one at a time:. The -n 1 option tells xargs to treat each line of the text file as a single parameter.
Checking in the file browser shows the multiple files have been downloaded. Each one bears the name it had on the remote server. Using curl with a File Transfer Protocol FTP server is easy, even if you have to authenticate with a username and password. This is a free-for-testing FTP server hosted by Rebex. Use the same command as a moment ago, with the filename appended to it:. In almost all cases, it is going to be more convenient to have the retrieved file saved to disk for us, rather than displayed in the terminal window.
Once more we can use the -O remote file output command to have the file saved to disk, with the same filename that it has on the remote server. The file is retrieved and saved to disk. We can use ls to check the file details. It has the same name as the file on the FTP server, and it is the same length, bytes. Some remote servers will accept parameters in requests that are sent to them. The parameters might be used to format the returned data, for example, or they may be used to select the exact data that the user wishes to retrieve.
It is often possible to interact with web application programming interfaces APIs using curl. To demonstrate the usage of the curl program, first, we need a dummy file to download.
Any online file will work for this, as long as you have the direct download link. For this guide, I will use the small file provided by think broadband. This is a very basic way of using curl. We will download the dummy file. With this flag, the file will be downloaded and saved at the current working directory. Need to download multiple files? Follow the command structure shown below. Curl allows you to limit the download speed.
Here, the download speed is limited to 1mb. It is also possible to manage an FTP server using curl.
0コメント