I would like to remove empty lines from begin and the end of file, but not remove empty lines between lines. I think sed or awk would be the solution.

Source:

1:
2:
3:line1
4:
5:line2
6:
7:
8:

Output:

1:line1
2:
3:line2

I would like to remove empty lines from the beginning and the end of file, but not remove empty lines between non-empty lines in the middle. I think sed or awk would be the solution.

Source:

1:
2:
3:line1
4:
5:line2
6:
7:
8:

Output:

1:line1
2:
3:line2

I would like to remove empty lines from begin and the end of file, but not remove empty lines between lines.

Source:

1:
2:
3:line1
4:
5:line2
6:
7:
8:

Output:

1:line1
2:
3:line2

I would like to remove empty lines from begin and the end of file, but not remove empty lines between lines. I think sed or awk would be the solution.

Source:

1:
2:
3:line1
4:
5:line2
6:
7:
8:

Output:

1:line1
2:
3:line2