Ok here's my pickle. I have a file in which every line must be the same length. Each field within the line is a certain length. None of these can be changed. What I need to do is look at a specific field within this file, let's say it starts with character 30 and ends with 50. If this field is empty, I need it to be replaced with a bit of text.
An example. Note that field 3 below in the first line is blank. I need to make it look like line2. Also, it should ignore the line if there is anything at all in the field as in line 2 and 3.
Code:
field1field2 field4
field1field2field3 field4
field1field2sometext field4
Any help would be appreciated as I'm horrible with
sed.
