Question

This example removes the fifth occurrence of a regular expression:

printf "%s " $(seq 9) | gawk '{ print gensub(/[0-9]/,"","5") }'
1 2 3 4  6 7 8 9 

This example removes the sixth instance of a regular expression:

printf "%s " $(seq 9) | gawk '{ print gensub(/[0-9]/,"","6") }'
1 2 3 4 5  7 8 9 

Is possible to save the above examples in one?
I tried it, but it does not work:

printf "%s " $(seq 9) | gawk '{ print gensub(/[0-9]/,"","5|6") }'
 2 3 4 5 6 7 8 9 

I want printed:

1 2 3 4    7 8 9

Answer 1

According to the documentation, the one of the ways I can think of:

printf "%s " $(seq 9) | gawk 'END{ print gensub(/[0-9]/,"","5",gensub(/[0-9]/,"","5")) }'

And another way (with your very specific input):

printf "%s " $(seq 9) | gawk 'END { print gensub(/[0-9] [0-9]/,"","3") }'

Search the target string target for matches of the regular expression
regexp. If how is a string beginning with ‘g’ or ‘G’ (short for
“global”), then replace all matches of regexp with replacement.
Otherwise, how is treated as a number indicating which match of regexp
to replace. If no target is supplied, use $0. It returns the modified
string as the result of the function and the original target string is
not changed.