Help downloading Sentinel-2 data using wget on Linux

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#1

I am trying to download Sentinel-2 data from Linux with wget command. I have a list of many UUIDs (one example is shown) and am developing a script to download many tiles. I am following instructions that I found here: https://scihub.copernicus.eu/twiki/do/view/SciHubUserGuide/BatchScripting?redirectedfrom=SciHubUserGuide.8BatchScripting
I am using this syntax, (with my username and password in place of XXs)

wget --content-disposition --continue --user={XX} --password={XX}“https://scihub.copernicus.eu/dhus/odata/v1/Products(‘e05be5b0-eab7-4b61-8089-68ed5bcaf6df’)/$value”

I get an error saying “value: Undefined variable.”

Does anyone know my mistake? I have tired various combinations of forward/back slashes before the $value. What is the logic of $value? Should i set that independently prior to executing wget? If i omit $value it complains that there is no url.

Any help would be much appreciated
Thank you
Lynsey Parker

#2

Do you need to escape the ‘$’ character by ‘’?

#3

If you read on in the instructions you will see that when using a “Unix Shell” the URL needs to have $value (here, “Unix” refers to a variety of operating systems including macOS and linux. For linux, the terminal typically uses the bash shell, which is one (of many) Unix Shell programs).

NOTE: Depending on the programming language used for scripting, the dollar ($) character might be interpreted as a wildcard character and not as a string value. The examples in this page are in Unix Shell and the backslash (\) needs to be used as escape character for the dollar ($) character.

Users new to the linux command line find it helpful to dedicate some time to learning linux command-line basics. There are many good resources, including youtube videos (search for site:youtube.com linux shell). A good place to start is Linux Command.

#4

Thank you. I was using csh and getting an error with the $value, but i switched to bash and it worked. Thank you!

#5

In this case, csh is actually more helpful than bash, but because bash is the default for the terminal in most linux distros, most online recipes assume bash:

 % bash -c 'echo a\$a a$a'
a$a a
% csh -c 'echo a\$a a$a'
a: Undefined variable.

For the download example, without the backslash (\), bash would run wget with an incomplete URL, while csh would not run wget at all.