Using the for loop download each file associated with the internet addresses contained in the file. The for loop can be used in Unix any time you need to repeat some actions until some condition changes.
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https://www.youtube.com/watch?v=XI4YNCjQvxg
Updating a freshly installed Open Solaris Operating system on a PC or virtual machine using the pkg command line tool
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https://www.youtube.com/watch?v=EAbt8es4EVU