通过保留 bash 中的第一行来删除与特定模式匹配的所有行

Question

I want to edit a gtf file by deleting all the lines except the first line matching pattern 'FAT1' and modify the coordinates ( 3rd & 4th columns).

#!genome-build GRCh38.p7
#!genome-version GRCh38
#!genome-date 2013-12
#!genome-build-accession NCBI:GCA_000001405.22
#!genebuild-last-updated 2016-06
1       havana  exon    137682  137965 gene_id "ENSG00000239906"; gene_version "1"; gene_name "RP11-34P13.16"; gene_source "havana";
1       havana  gene    139790  140339  gene_id "ENSG00000239906"; gene_version "1"; gene_name "RP11-34P13.14"; gene_source "havana"; 
1       havana  exon    140001  140101 gene_id "ENSG00000269981"; gene_version "1"; gene_name "FAT1"; gene_source "havana";
1       havana  gene    143401  145401  gene_id "ENSG00000269981"; gene_version "1"; gene_name "FAT1"; gene_source "havana"; 

expected output

#!genome-build GRCh38.p7
#!genome-version GRCh38
#!genome-date 2013-12
#!genome-build-accession NCBI:GCA_000001405.22
#!genebuild-last-updated 2016-06
1       havana  exon    137682  137965 gene_id "ENSG00000239906"; gene_version "1"; gene_name "RP11-34P13.16"; gene_source "havana";
1       havana  gene    139790  140339  gene_id "ENSG00000239906"; gene_version "1"; gene_name "RP11-34P13.14"; gene_source "havana"; 
1       havana  exon    147653  148000 gene_id "ENSG00000269981"; gene_version "1"; gene_name "FAT1"; gene_source "havana";

---

I tried some thing like this.

    # Keep only the unique entry for FAT1 gene. 
    awk '/"ENSG00000269981"/&&c++ {next} 1' ref.gtf > ref_edit.gtf 

   #then manually edit the coordinates in vim editor

But i'm sure there will be more reasonable solution.

Answer 1

Could you please try following.

awk -v new_fourth_col="147653" -v new_fifth_col="148000" '
BEGIN{
  OFS="\t"
}
/gene_name "FAT1"/{
  if(++count==1){
    $4=new_fourth_col
    $5=new_fifth_col
    print
  }
  next
}
{
  $1=$1
  print
}
' Input_file

Also I have made your output as tab delimited.