Actual bash string storing awk source [closed]

Question

I have been calling awk commands from bash using the customary single quotes. How can one use an actual string to store the awk source, then introduce that to tho awk command later?

printf '%s\n' "$@"  \
  | awk -v frg="$ctp" -v rst="$sgr" -v prl="$rl"  \
    '{ if ( $0 ~ prl ) {
         fm = "%s%s%s\n" ; printf(fm, frg, $0, rst) }
       else {
         fm = "%s\n" ; printf(fm, $0) }
     }'

The change would be

str="
{ if ( $0 ~ prl ) {
    fm = "%s%s%s\n" ; printf(fm, frg, $0, rst) }
  else {
    fm = "%s\n" ; printf(fm, $0)
   }
}"

Then I would perhaps call the command with

printf '%s\n' "$@"  \
  | awk -v frg="$ctp" -v rst="$sgr" -v prl="$rl" "$str"

Answer 1

Without more info on the problem you're trying to solve - don't store code in a string, use a function:

foo() {
  awk -v frg="$ctp" -v rst="$sgr" -v prl="$rl"  \
    '{ if ( $0 ~ prl ) {
         fm = "%s%s%s\n" ; printf(fm, frg, $0, rst) }
       else {
         fm = "%s\n" ; printf(fm, $0) }
     }'
}

printf '%s\n' "$@"  \
  | foo

or:

foo() {
  awk -v frg="$1" -v rst="$2" -v prl="$3"  \
    '{ if ( $0 ~ prl ) {
         fm = "%s%s%s\n" ; printf(fm, frg, $0, rst) }
       else {
         fm = "%s\n" ; printf(fm, $0) }
     }'
}

printf '%s\n' "$@"  \
  | foo "$ctp" "$sgr" "$rl"

or similar.

That way you encapsulate the functionality you want from your awk script while avoiding tightly coupling your shell script to your awk script.