Catranges
You know that you can get a range of lines from the beginning of a file with the utility
head, and from the end with
tail. Thus, by chaining these tools you can select a range of lines from the middle (or you use
sed or
awk, which allow you to do this directly). But what if you want to extract a regularly repeated pattern of lines?
Probably there would be a way to do this also directly in
awk, but I do not know it. Anyway, I have written a tool
catranges to do just that. It allows you to specify an initial range of lines to skip, and then in a loop echoes N lines and skips S lines until the end-of-file. As always, it is written in pure C99, and it is organized as a filter, thus, by chaining with
tr, you are not restricted for extracting lines, but can use any separator character you like.
Here is the source code. It is so trivial, thus I allow you to do with it anything you want (i.e., I attach no licence requirements to it).
