0

I would like to execute some basic mathematical calculations in batch/Cygwin, but the solution, described in StackOverflow question: Calculating the sum of two variables in a batch script is using the set /A command for that matter.

This does not suit me, because I'd like to have everything in a pipe (UNIX style, hence the Cygwin).

My idea is the following: I have a list of files, containing an entry. I'd like to show, for all mentioned file, the one line behind that entry.

Therefore I was thinking about following approach:

Find the line where the entry is found: fgrep -n <entry> // this shows the line number together with the entry itself
Only show the line number: fgrep -n <entry> | awk -F ':' '{print $1}'
Add '1' to that number
Take the first amount of entries : head -<new number>
Only take the last line : tail -1

But as I don't know how to add 1 to a number, I am stuck here.

I've already tried using bc (basic calculator) but my Cygwin installation seems not to cover that. As I want to have everything within one piped line, the usage of set /A has not sence.

Does anybody have an idea?
Thanks in advance

Community
  • 1
  • 1
Dominique
  • 16,450
  • 15
  • 56
  • 112

2 Answers2

0

Sorry, sorry, I just realised that awk is capable of doing some basic calculations, so by replacing {print $1} by {print $1 + 1} my problem is solved.

Dominique
  • 16,450
  • 15
  • 56
  • 112
0

Bash has builtin support for declaring variables to be integer and for doing arithmetic on integers. Bash has a help command and you should have both man bash and info bash installed.

Doug Henderson
  • 785
  • 8
  • 17