executing custom format for outfmt format 7

Question

[vigneshprbh37]

I want to pull out the query length from the results of my tblastn. Can anyone give me the format for including custom formats such as qgi, qacc, qlen?

Answer 1

[iraun]

If you type blastn -help, you can see all the formatting options available at -outfmt:

*** Formatting options
 -outfmt <String>
   alignment view options:
     0 = pairwise,
     1 = query-anchored showing identities,
     2 = query-anchored no identities,
     3 = flat query-anchored, show identities,
     4 = flat query-anchored, no identities,
     5 = XML Blast output,
     6 = tabular,
     7 = tabular with comment lines,
     8 = Text ASN.1,
     9 = Binary ASN.1,
    10 = Comma-separated values,
    11 = BLAST archive format (ASN.1)

   Options 6, 7, and 10 can be additionally configured to produce
   a custom format specified by space delimited format specifiers.
   The supported format specifiers are:
           qseqid means Query Seq-id
              qgi means Query GI
             qacc means Query accesion
          qaccver means Query accesion.version
             qlen means Query sequence length
           sseqid means Subject Seq-id
        sallseqid means All subject Seq-id(s), separated by a ';'
              sgi means Subject GI
           sallgi means All subject GIs
             sacc means Subject accession
          saccver means Subject accession.version
          sallacc means All subject accessions
             slen means Subject sequence length
           qstart means Start of alignment in query
             qend means End of alignment in query
           sstart means Start of alignment in subject
             send means End of alignment in subject
             qseq means Aligned part of query sequence
             sseq means Aligned part of subject sequence
           evalue means Expect value
         bitscore means Bit score
            score means Raw score
           length means Alignment length
           pident means Percentage of identical matches
           nident means Number of identical matches
         mismatch means Number of mismatches
         positive means Number of positive-scoring matches
          gapopen means Number of gap openings
             gaps means Total number of gaps
             ppos means Percentage of positive-scoring matches
           frames means Query and subject frames separated by a '/'
           qframe means Query frame
           sframe means Subject frame
             btop means Blast traceback operations (BTOP)
          staxids means unique Subject Taxonomy ID(s), separated by a ';'
                (in numerical order)
        sscinames means unique Subject Scientific Name(s), separated by a ';'
        scomnames means unique Subject Common Name(s), separated by a ';'
       sblastnames means unique Subject Blast Name(s), separated by a ';'
                (in alphabetical order)
       sskingdoms means unique Subject Super Kingdom(s), separated by a ';'
                (in alphabetical order)
           stitle means Subject Title
       salltitles means All Subject Title(s), separated by a '<>'
          sstrand means Subject Strand
            qcovs means Query Coverage Per Subject
          qcovhsp means Query Coverage Per HSP
   When not provided, the default value is:
   'qseqid sseqid pident length mismatch gapopen qstart qend sstart send

So, if you want to retrieve qgi, qacc, qlen you should specify it with: -outfmt '7 qgi qacc qlen'

Is this what you are looking for?