Stripping all vowels but the first from a set of strings

Question

I have a string comprised of multiple substrings, separated by underscores. For example: AbcdAEfd_hEgdgE_AbAAAAA. I need to remove all vowels except the first from each substring. So:

• AbcdAEfd -> Abcdfd
• hEgdgE -> hEgdg
• AbAAAAA -> Ab

The resulting string should be Abcdfd_hEgdg_Ab

Answer 1

Pure bash solution, using just parameter substitution:

#! /bin/bash
suffix=${1#*[aeiou]}
prefix=${1%$suffix}
vowel=${prefix: -1}
prefix=${prefix%?}                  # Remove the vowel from the prefix
suffix=${suffix//[aeiou]/}          # Remove the vowels.
echo "$1 -> $prefix$vowel$suffix."

Answer 2

You can use perl's zero-width look-behind regex syntax.

perl -pe "s/(?<=[aeiou])([^aeiou_]*)[aeiou]([^aeiou_]*)/\1\2/ig"

This next snippet treats an input line as a single string (not multiple sub-strings).

perl -pe "s/(?<=[aeiou])([^aeiou]*)[aeiou]/\1/ig"

Answer 3

Does python count? This should work:

cat anonymous.txt | python -c "import sys; x=sys.stdin.read(); print(x[0]+''.join([z for z in x[1:] if z not in 'AEIOUaeiou']))"

I tried with tee and named pipes as well, but it kinda failed:

makefifo pipe; cat anonymous.txt | tee >(cut -b1 >> pipe&) >(cut -b1- | tr -d aeiouAEIOU >> pipe&) > /dev/null; cat pipe | xargs -d '\n'

Answer 4

This might work for you (GNU sed):

sed 's/^/\n/;ta;:a;s/\n$//;t;s/\n\([^aeiou_]*[aeiou]\)/\1\n/i;:b;s/\n\([^aeiou_]*\)[aeiou]/\1\n/i;tb;s/\n\([^aeiou]*\)/\1\n/i;ta' file