UNIX for Dummies Questions & Answers

I want to write a simple script which will have a list of numbers. And I want to take the first number on the list, put it into a variable, use this variable to use sed to print out a line in another document. Allow me to show you an example.

File1
5
4
3
2
1

File2
This is line 1
This is line 2
This is line 3
This is line 4
This is line 5

Script
#!/bin/sh
variable= head -1 File1
sed -n '$variable p'

(How to remove the first line from File1, and redirect the output into the same file, overwriting it. Repeat process until the file has pointed to each line on the document.

Is this... not as simple as i'm thinking? Missing out some important concepts I should be learning?

Any help is greatly appreciated.

Why overwrite file1? Why sed? What exactly is your desired output and resulting files?
I do not see a reason to do what you are doing what you say you want to do.

I'm trying to make a list of numbers in one file, point to the respective lines in another file, and make no line repeat itself.

So File1 has numbers 1 to 5
File2 has some text, 5 lines of it.

The first line in File1 is lets say "5"

so I want to take that number, and tell unix, okay, now print out line 5 in File2.

I wanted to replace the original file because I wasn't sure how to make it traverse the list without repeating itself

And I tried using sed, because it's the only command I know which can directly print out a line of a file, no questions asked.