one liner, how do you know which match happened ...

[Albretch Mueller <lbrtchx@gmail.com>]

_X=".\(html\|txt\)"
_SDIR="$(pwd)"

_AR_TERMS=(
Kant
"Gilbert Ryle"
Hegel
)

for iZ in ${!_AR_TERMS[@]}; do
 find "${_SDIR}" -type f -iregex .*"${_X}" -exec grep -il
"${_AR_TERMS[$iZ]}" {} \;
done # iZ: terms search/grep'ped inside text files;  echo "~";


# this would be much faster

find "${_SDIR}" -type f -iregex .*"${_X}" -exec grep -il
"Kant\|Gilbert Ryle\|Hegel" {} \;

but how do I know which match happened in order to save it into separate files?

 grep doesn't do replacements:

 https://stackoverflow.com/questions/16197406/grep-regex-replace-specific-find-in-text-file

 but at least (in my way to understand reality, since it must try such
searches sequentially) it should give  you the index of the match and
if grep doesn't do that I am sure some other batch utility would (I
havenever used sed in my code)

 lbrtchx