awk : search last index in specific column

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# 8  
Old 10-29-2013
match also sets the RSTART and RLENGTH variables, so your proposal could be written as
awk -F\| 'match ($NF, /n[^n]*$/) {print $0, RSTART}' OFS=\| file
111|lkasjdfaaa|555|tarun trehan|12
65876111|aaa|555|allzhere android apps|11
111|hhhaaa|555|allzhere on facebook|11
111|aaa|555|contact updater utility|3

This User Gave Thanks to RudiC For This Post:
# 9  
Old 10-29-2013
Originally Posted by RavinderSingh13
Sorry to bother you, I have tried searching the match expression given by you in code but was not able to under stand it could you please exaplain it.
Regexp /n[^n]*$/ means search for a pattern n n followed by zero or more occurrence of any character other than n [^n]* at the end of string $

So for string RavinderSingh13, this regexp will match the last n and return the index or character position:
$ echo "RavinderSingh13" | awk '{ print match ( $0, /n[^n]*$/ ) }'

This User Gave Thanks to Yoda For This Post:
# 10  
Old 10-29-2013
You could also use:

awk -F\| '
{ for(F=0; match(substr($4,F+1),"n"); F+=RSTART);
F' OFS=\| names_file.txt

Edit: RudiC's solution #8 is similar but better implemented!

However, this is still a valid method if the match item is more than 1 character (or even an RE in it's own right).

Last edited by Chubler_XL; 10-29-2013 at 05:54 PM..
# 11  
Old 10-29-2013
# 12  
Old 10-30-2013

Thanks for the inputs. nawk works but have another challenge here:
The string to search for is dynamic and hence needs to passed as a variable to awk.

I tried the following code though i was not confident about it.
Doesn't work as expected. Can you please provide your inputs here :

export SRCH_PARAM="an"
nawk -v X="$SRCH_PARAM" -F\| '
	for ( i = 1; i <= NF; i++ )
			n = match ( $4, /n[^X]*$/ )
	if ( n )
	print $0 OFS n
} ' OFS=\| names_file.txt

# 13  
Old 10-30-2013
awk -F\| -v X="an" 'match ($NF, ".*"X) {print $0, RLENGTH-length(X)+1}' OFS=\| file
111|lkasjdfaaa|555|tanrun trehan|12
65876111|aaa|555|allzhere android apps|10

# 14  
Old 10-30-2013
Try this:

export SRCH_PARAM="an"
nawk -v X="$SRCH_PARAM" -F\| '
{ for(F=0; match(substr($4,F+1),X); F+=RSTART);
F' OFS=\| names_file.txt

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