Replace the third comma on each line with newline

Using GNU sed:

sed "s/,/\n/3; G" file ETRYTUUI,YTYUIL,UIOKJHGFGH 34567898766 

Explanation💡:

sed stands for stream editor..sed has the following syntax:

substitute/match(or pattern)/replacement/position file 

In the above command, s substitute the third , by a new line \n.

G is to append a new line to the contents of the pattern space and then append the contents of the hold space to the pattern space.

awk -F, -vOFS=, '{print $1,$2,$3; print $4; print ""}' file 

will produce your desired output

A few Perl approaches:

$ perl -pe 's/,([^,]+)$/\n$1\n/' file AKJHGFGUIKL,OIUYT,KJHBTYUI 98765434567 RTYUIKHGFGH,TYUJI,TGHYJKJKLJKL 6789876 ETRYTUUI,YTYUIL,UIOKJHGFGH 34567898766 

The -p means "read the input file line by line and print each line after applying the script given by -e to it". The s/foo/bar/ is the substitution operator which will replace foo with bar. Here, we are matching a comma followed by one or more non-comma characters ([^,]+) until the end of the line ($). The parentheses around the ([^,]+) will "capture" whatever is matched so we can refer to it as $1 on the right hand side of the operator. Therefore, this will replace the text after the last comma with a newline, then the matched text and then another newline.

If you can't be sure the third comma is the last one, you can do:

perl -pe 's/([^,]+,){3}\K(.+)/\n$2\n/' file 

or

perl -pe 's/(.+?,.+?,.+?),(.+)/$1\n$2\n/' file 

And here are some more, just for fun:

perl -pe 's/([^,]+,){3}\K(.+)/\n$2\n/' file perl -F, -pe '$k=pop(@F); $_=join(",", @F)."\n$k\n"' file perl -F, -le 'print join ",", @F[0..2],"\n@F[3..$#F]\n"' file 

Alternative less succinct sed code:

sed 's/,\([^,]*\)/\n\1\n/3' file 

...which can be used if the hold buffer were needed for some other purpose, (supposing some additional requirement). If you need portable code (the above is gnu sed syntax) use literal newlines in the RHS:

sed 's/,\([^,]*\)/\ \1\ /3' file 

awk -F, '{print $1, $2, $3,"\n"$4}' 

A more portable sed solution:

<infile sed -E 'G;s/(.*),(.*)(\n)/\1\3\2\3/' 

Awk solution(s):

<infile awk -F, '{printf("%s,%s,%s\n%s\n\n",$1,$2,$3,$4)}' <infile gawk '{match($0,/(.*),(.*)/,a);print(a[1]"\n"a[2]"\n")}'