Insert X after every Y sequences in file

Find · 01-08-2013, 10:16 AM

How do I insert "X" after every #Y sequences in file? I want to use sed or grep or some ubiquitous *inx software.

For example:
File =

Code:

`abcd,efg,hi ,jkl,  m`

X = (backspace and then a dollar symbol then newline)

Code:

`\b$\n`

Sequence = (anything and then a comma - but only anything once - eg. not-greedy )

Code:

`*,`

Y =

Code:

`2`

New File =

Code:

`abcd,efg$
hi ,jkl$
 m`

Thanks!

allend · 01-08-2013, 08:15 PM

Persoanlly, I would approach this by a bash script.

This is some outline pseudo code

Code:

IFS=","
while read -a aline
  for=1 to sizeof aline; do
    if (i modulo Y not equal to zero) AND (i less than sizeof aline)
      echo -n aline[i-1]","
    elif (i equals sizeof aline)
      echo aline[i]
    else
      echo aline[i-1]"$"
    fi
  done
done << inputfile