add a blank line after particular line

Question

[amoltej]

Hi,

I have a file as follows -

Mp1087439_TGAC_V1.1_scaffold_1    exon    51615    51678    gene_id "3_g"; transcript_id "3_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    53627    53777    gene_id "3_g"; transcript_id "3_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    56113    56171    gene_id "3_g"; transcript_id "3_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    61779    61841    gene_id "4_g"; transcript_id "4_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    61942    62137    gene_id "4_g"; transcript_id "4_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    62322    62513    gene_id "4_g"; transcript_id "4_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    62596    62762    gene_id "4_g"; transcript_id "4_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    63136    63331    gene_id "4_g"; transcript_id "4_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    73319    73368    gene_id "5_g"; transcript_id "5_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    75842    76266    gene_id "5_g"; transcript_id "5_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    76572    76766    gene_id "5_g"; transcript_id "5_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    77576    77751    gene_id "5_g"; transcript_id "5_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    103158    103301    gene_id "6_g"; transcript_id "6_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    103375    103576    gene_id "6_g"; transcript_id "6_t";

I want to add a blank line after the gene_id changes. and it should look like

Mp1087439_TGAC_V1.1_scaffold_1    exon    51615    51678    gene_id "3_g"; transcript_id "3_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    53627    53777    gene_id "3_g"; transcript_id "3_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    56113    56171    gene_id "3_g"; transcript_id "3_t";

Mp1087439_TGAC_V1.1_scaffold_1    exon    61779    61841    gene_id "4_g"; transcript_id "4_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    61942    62137    gene_id "4_g"; transcript_id "4_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    62322    62513    gene_id "4_g"; transcript_id "4_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    62596    62762    gene_id "4_g"; transcript_id "4_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    63136    63331    gene_id "4_g"; transcript_id "4_t";

Mp1087439_TGAC_V1.1_scaffold_1    exon    73319    73368    gene_id "5_g"; transcript_id "5_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    75842    76266    gene_id "5_g"; transcript_id "5_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    76572    76766    gene_id "5_g"; transcript_id "5_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    77576    77751    gene_id "5_g"; transcript_id "5_t";

Mp1087439_TGAC_V1.1_scaffold_1    exon    103158    103301    gene_id "6_g"; transcript_id "6_t";
Mp1087439_TGAC_V1.1_scaffold_1    exon    103375    103576    gene_id "6_g"; transcript_id "6_t";

Can somebody please help me

Thanks

Answer 1

[iraun]

This awk command should work:

awk -F'\t' 'NR==1{split($5, a, ";");prevGen=a[1];print}{split($5, a, ";");if (a[1] == prevGen){print}else{print "\n"$0};prevGen=a[1]}' file

[amoltej]

Thank you so much. This is very fast than other answer

Answer 2

[5heikki]

A very graceless way, assumes a tab-separated file, adds a blank line to the top..

TEST=$(printf "empty"); while IFS=$'\t' read -r NAME TYPE START END GENEID TRANSCRIPTID; do if [ "$TEST" == "$GENEID" ]; then printf "$NAME\t$TYPE\t$START\t$END\t$GENEID\t$TRANSCRIPTID\n"; else printf "\n$NAME\t$TYPE\t$START\t$END\t$GENEID\t$TRANSCRIPTID\n" && TEST=$(printf "$GENEID"); fi; done<inputFile

[amoltej]

Thank you so much