awk use sequential line numbering in output

Shell Programming and Scripting
1

The awk below produces an output with the original header and only the matching lines (which is good), but the output where the original line numbering in the match found on is used. I can not figure out how to sequentially number the output instead of using the original.

I did try to add {$1=++n; print} before the FNR==1 and though it executed the output was not correct. Thank you :).

file1

LYST	NM_000081.3	chr1	235972867	235972867
MSH6	NM_000179.2	chr2	48027375	48027375

file2

R_Index	Chr	Start	End	Ref	Alt	Func.refGeneWithVer	Gene.refGeneWithVer
1362	chr1	235972867	235972867	T	C	exonic	LYST
5	chr1	985239	985239	C	T	splicing	AGRN
1701	chr2	48027375	48027375	T	C	exonic	MSH6

awk

awk -F'\t' 'NR==FNR{c[$1$3$4]++;next};c[$8$2$3] > 0; FNR==1' file1 file2

current output

R_Index	Chr	Start	End	Ref	Alt	Func.refGeneWithVer	Gene.refGeneWithVer
1362	chr1	235972867	235972867	T	C	exonic	LYST
1701	chr2	48027375	48027375	T	C	exonic	MSH6

desired output

R_Index	Chr	Start	End	Ref	Alt	Func.refGeneWithVer	Gene.refGeneWithVer
1	chr1	235972867	235972867	T	C	exonic	LYST
2	chr2	48027375	48027375	T	C	exonic	MSH6
2 
awk -F'\t' 'NR==FNR{c[$1$3$4]++;next}c[$8$2$3]>0{$1=++n;print}FNR==1' OFS='\t' file1 file2
1 Like
3

Thank you very much :).