[ALUG] Manipulating files from bash

Mark Rogers mark at more-solutions.co.uk
Fri Sep 22 17:05:16 BST 2017


There are lots of ways to process text files (eg sed, awk, etc); I'm
after suggestions on the best/easiest way to achieve something fairly
trivial to describe.

Below is example output from sfdisk -d:

   label: dos
   label-id: 0xe3f4f21a
   device: /dev/sdd
   unit: sectors

   /dev/sdd1 : start=        8192, size=       85622, type=c
   /dev/sdd2 : start=       94208, size=     5521408, type=83
   /dev/sdd3 : start=     5615616, size=    25499648, type=83

I want to convert this into a new script to go back into sfdisk but
with some changes; I want the start values skipped (so sfdisk will put
partition boundaries wherever it thinks is best), I want the last
sector not have a size (ie "rest of disk"), and I don't really need
any of the settings at the top.

In fact, a suitable (minimal) script to go into sfdisk would be simply:
  ,85622,c
  ,5521408
  ,;

I don't really mind at this point whether I end up with something more
like the first format or minified like the latter. In fact to be
honest I'm more interested just in learning the best ways to play with
text files like this.

-- 
Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450
Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER



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