Give name for every nth line

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1

Hi all,

Greetings. I am facing some troubles and hope that the professionals here could help me.

I am handling a large dataset, and part of it is like below:

1	ab139	0	752566	G	A
1	ab151	0	846808	T	C
1	ab142	0	854250	G	A
1	ab061	0	861808	A	G
1	ab043	0	873558	T	G
1	ab034	0	882033	A	G
1	ab395	0	888659	T	C
1	ab608	0	891945	A	G
1	ab100	0	894573	G	A
1	ab109	0	903104	T	C
1	ab981	0	904165	A	G
1	ab682	0	918384	G	T
2	ab293	0	112433668	T	C
2	ab204	0	112435483	C	T
2	ab331	0	112437140	A	G
2	ab691	0	112444459	T	G
2	ab104	0	121202941	C	T
2	ab107	0	121203511	T	C
2	ab029	0	121214402	T	C
2	ab988	0	121214469	T	G
2	ab666	0	121216828	T	G
2	ab422	0	121217568	A	G
3	ab555	0	63754993	G	T
3	ab443	0	63779288	C	T
3	ab332	0	63785436	C	T
3	ab991	0	63788331	G	A
3	ab111	0	63811369	A	C
3	ab698	0	63824453	T	C
3	ab327	0	63838796	G	A
3	ab570	0	63842062	A	G
3	ab110	0	72360478	T	C
3	ab991	0	72361951	G	A
3	ab867	0	72382471	A	G
3	ab117	0	72386350	A	G
3	ab101	0	72387348	G	A
3	ab871	0	72387926	T	C

How can I add an indicator after 5 lines like the output below?

1	ab139	0	752566	G	A	Fr1.1
1	ab151	0	846808	T	C	Fr1.1
1	ab142	0	854250	G	A	Fr1.1
1	ab061	0	861808	A	G	Fr1.1
1	ab043	0	873558	T	G	Fr1.1
1	ab034	0	882033	A	G	Fr1.2
1	ab395	0	888659	T	C	Fr1.2
1	ab608	0	891945	A	G	Fr1.2
1	ab100	0	894573	G	A	Fr1.2
1	ab109	0	903104	T	C	Fr1.2
1	ab981	0	904165	A	G	Fr1.3
1	ab682	0	918384	G	T	Fr1.3
2	ab293	0	112433668	T	C	Fr2.1
2	ab204	0	112435483	C	T	Fr2.1
2	ab331	0	112437140	A	G	Fr2.1
2	ab691	0	112444459	T	G	Fr2.1
2	ab104	0	121202941	C	T	Fr2.1
2	ab107	0	121203511	T	C	F2.2
2	ab029	0	121214402	T	C	F2.2
2	ab988	0	121214469	T	G	F2.2
2	ab666	0	121216828	T	G	F2.2
2	ab422	0	121217568	A	G	F2.2
3	ab555	0	63754993	G	T	Fr3.1
3	ab443	0	63779288	C	T	Fr3.1
3	ab332	0	63785436	C	T	Fr3.1
3	ab991	0	63788331	G	A	Fr3.1
3	ab111	0	63811369	A	C	Fr3.1
3	ab698	0	63824453	T	C	Fr3.2
3	ab327	0	63838796	G	A	Fr3.2
3	ab570	0	63842062	A	G	Fr3.2
3	ab110	0	72360478	T	C	Fr3.2
3	ab991	0	72361951	G	A	Fr3.2
3	ab867	0	72382471	A	G	Fr3.3
3	ab117	0	72386350	A	G	Fr3.3
3	ab101	0	72387348	G	A	Fr3.3
3	ab871	0	72387926	T	C	Fr3.3

Can sed/awk do this? Please help me, your comments are very much appreciated. Thank you very much for your kind helps in advance.

Best wishes,
Amanda
(Is x86_64 GNU/Linux)

2

Try

awk '{a++;if(!(a%5) || NR==1){s++}
    {if(P != $1){s=1;a=0}}
    {P=$1;$(NF+1)="Fr"$1"."s}}1' file
3 
awk -F'\t' 'p1!=$1{c=1;n=1}
{$(NF+1)= "Fr" $1 "." n}
!(c%5){n++}
{c++;p1=$1}1' OFS='\t' file
4

Dear pamu and elixir sinari,

Thank you very much! It works!! Really helps a lot.

Best wishes,
Amanda

5

knowing it's a bit late, I couldn't resist:

awk     '$1!=sav {sav=$1;n=i=0}
          {n+=!(i++%5); print $0,"Fr"$1"."n}
    ' FS="\t" OFS="\t" file