Cleaning up a text file with compact regex

neversaint has asked for the wisdom of the Perl Monks concerning the following question:

Dear Masters,
Given this files ('file.txt') how can I use a compact regex to clean it so that from this:

<h3>Warning</h3><blockquote><FONT SIZE=+1 color=#aa0000><B>
Circular contig    NC_001224.1    leftmost feature    0    Q0050    le
+ft neighbour    Q0275
</B></FONT></blockquote><BR><HR SIZE=3>
<h3>Warning</h3><blockquote><FONT SIZE=+1 color=#aa0000><B>
Circular contig    NC_001224.1    rightmost feature    18    Q0275    
+right neighbour    Q0045
</B></FONT></blockquote><BR><HR SIZE=3>
>YJR152W|DAL5
TGATTTTGGATATTCATCAAAGGAAACCCTATTAATGGGTTTACCTACAGGTGCTGTTGA
ATTGGTAGGTTGTCCACTTTTTGGTATTCTAGCAGTTTATGCAGCCAATAAGAAGATACC
ATTTTGGAAATATAAGTTGAGTTGGGCTATTTTTGCAGCTGTCTTAGCATTGATTGCTAG
CTGCATGTTAGGGTTTGCAACAAACTCCAAAAAAGCAAGACTGGCTGGTGCTTACCTGTG
GTACATCTCGCCCGTCTCATTTATTTGCGTACTTTCCAATATCAGTGCGAATTCCTCGGG
ATATAGTAAAAAATGGACTGTATCTTCAATAAACTTAGTAGCATATGCTGCAGCTAACTT
GGCAGGACCACAAACCTTTATTGCTAAGCAGGCTCCTAAATATCATGGCGCTAAGGTCGC
TATGGTCGTATGTTATGCTGTTATGATCGTGCTTCTATCTATACTGCTCATCGTCAATTT
AAGGGAAAACAAGAGACGTGATAAGATAGCTGCCGAGAGAGGGTTCCCTGAAGAAACAGA
GAATTTAGAGTTTTCTGATTTGACTGATTTTGAAAATCCAAATTTCAGATACACTTTATG
>YKR039W|GAP1
CCTAGCTGAACAGAGATTTCTGCCAGAAATCTTTTCCTACGTTGACCGTAAGGGTAGACC
ATTGGTGGGAATTGCTGTCACATCTGCATTCGGTCTTATTGCGTTTGTTGCCGCCTCCAA
AAAGGAAGGTGAAGTTTTCAACTGGTTACTAGCCTTGTCTGGGTTGTCATCTCTATTCAC
ATGGGGTGGTATCTGTATTTGTCACATTCGTTTCAGAAAGGCATTGGCCGCCCAAGGAAG
AGGCTTGGATGAATTGTCTTTCAAGTCTCCTACCGGTGTTTGGGGTTCCTACTGGGGGTT
ATTTATGGTTATTATTATGTTCATTGCCCAATTCTACGTTGCTGTATTCCCCGTGGGAGA
TTCTCCAAGTGCGGAAGGTTTCTTCGAAGCTTATCTATCCTTCCCACTTGTTATGGTTAT
GTACATCGGACACAAGATCTATAAGAGGAATTGGAAGCTTTTCATCCCAGCAGAAAAGAT
GGACATTGATACGGGTAGAAGAGAAGTCGATTTAGATTTGTTGAAACAAGAAATTGCAGA
AGAAAAGGCAATTATGGCCACAAAGCCAAGATGGTATAGAATCTGGAATTTCTGGTGTTA
;WARNING    invalid query foo
;WARNING    invalid query bar
;WARNING    invalid query qux
[download]

we get simply:

>YJR152W|DAL5
TGATTTTGGATATTCATCAAAGGAAACCCTATTAATGGGTTTACCTACAGGTGCTGTTGA
ATTGGTAGGTTGTCCACTTTTTGGTATTCTAGCAGTTTATGCAGCCAATAAGAAGATACC
ATTTTGGAAATATAAGTTGAGTTGGGCTATTTTTGCAGCTGTCTTAGCATTGATTGCTAG
CTGCATGTTAGGGTTTGCAACAAACTCCAAAAAAGCAAGACTGGCTGGTGCTTACCTGTG
GTACATCTCGCCCGTCTCATTTATTTGCGTACTTTCCAATATCAGTGCGAATTCCTCGGG
ATATAGTAAAAAATGGACTGTATCTTCAATAAACTTAGTAGCATATGCTGCAGCTAACTT
GGCAGGACCACAAACCTTTATTGCTAAGCAGGCTCCTAAATATCATGGCGCTAAGGTCGC
TATGGTCGTATGTTATGCTGTTATGATCGTGCTTCTATCTATACTGCTCATCGTCAATTT
AAGGGAAAACAAGAGACGTGATAAGATAGCTGCCGAGAGAGGGTTCCCTGAAGAAACAGA
GAATTTAGAGTTTTCTGATTTGACTGATTTTGAAAATCCAAATTTCAGATACACTTTATG
>YKR039W|GAP1
CCTAGCTGAACAGAGATTTCTGCCAGAAATCTTTTCCTACGTTGACCGTAAGGGTAGACC
ATTGGTGGGAATTGCTGTCACATCTGCATTCGGTCTTATTGCGTTTGTTGCCGCCTCCAA
AAAGGAAGGTGAAGTTTTCAACTGGTTACTAGCCTTGTCTGGGTTGTCATCTCTATTCAC
ATGGGGTGGTATCTGTATTTGTCACATTCGTTTCAGAAAGGCATTGGCCGCCCAAGGAAG
AGGCTTGGATGAATTGTCTTTCAAGTCTCCTACCGGTGTTTGGGGTTCCTACTGGGGGTT
ATTTATGGTTATTATTATGTTCATTGCCCAATTCTACGTTGCTGTATTCCCCGTGGGAGA
TTCTCCAAGTGCGGAAGGTTTCTTCGAAGCTTATCTATCCTTCCCACTTGTTATGGTTAT
GTACATCGGACACAAGATCTATAAGAGGAATTGGAAGCTTTTCATCCCAGCAGAAAAGAT
GGACATTGATACGGGTAGAAGAGAAGTCGATTTAGATTTGTTGAAACAAGAAATTGCAGA
AGAAAAGGCAATTATGGCCACAAAGCCAAGATGGTATAGAATCTGGAATTTCTGGTGTTA
[download]

In principle we want to:

Delete first six lines
Delete lines that start with ; (semicolon)

---
neversaint and everlastingly indebted.......

Comment on Cleaning up a text file with compact regex Select or Download Code

Replies are listed 'Best First'.
Re: Cleaning up a text file with compact regex by chromatic (Archbishop) on Apr 24, 2007 at 05:51 UTC
`open( my $fh, '<', 'file.txt' ) or die "Cannot read file.txt: $!\n"; # clearer idiom, anyone? scalar <$fh> for 1 .. 6; while (<$fh>) { next if /^;/; # ... process lines }` [download]	[reply] [d/l]
Re^2: Cleaning up a text file with compact regex by betterworld (Curate) on Apr 24, 2007 at 09:49 UTC
`while (<$fh>)` You should always put `local($_);` before such a loop, because the global variable $_ is set to each line and is not cleaned up in the end. Update: http://perl.plover.com/local.html has an example of the dangers of this kind of `while` loop.	[reply] [d/l] [select]
Re: Cleaning up a text file with compact regex by Samy_rio (Vicar) on Apr 24, 2007 at 05:58 UTC
Try like this, TIMTOWDI use strict; use warnings; my @content = <DATA>; @content = grep!/^\;/, @content; print @content[6..$#content]; __DATA__ <h3>Warning</h3><blockquote><FONT SIZE=+1 color=#aa0000><B> Circular contig NC_001224.1 leftmost feature 0 Q0050 le +ft neighbour Q0275 </B></FONT></blockquote><BR><HR SIZE=3> <h3>Warning</h3><blockquote><FONT SIZE=+1 color=#aa0000><B> Circular contig NC_001224.1 rightmost feature 18 Q0275 +right neighbour Q0045 </B></FONT></blockquote><BR><HR SIZE=3> >YJR152W\|DAL5 TGATTTTGGATATTCATCAAAGGAAACCCTATTAATGGGTTTACCTACAGGTGCTGTTGA ATTGGTAGGTTGTCCACTTTTTGGTATTCTAGCAGTTTATGCAGCCAATAAGAAGATACC ATTTTGGAAATATAAGTTGAGTTGGGCTATTTTTGCAGCTGTCTTAGCATTGATTGCTAG CTGCATGTTAGGGTTTGCAACAAACTCCAAAAAAGCAAGACTGGCTGGTGCTTACCTGTG GTACATCTCGCCCGTCTCATTTATTTGCGTACTTTCCAATATCAGTGCGAATTCCTCGGG ATATAGTAAAAAATGGACTGTATCTTCAATAAACTTAGTAGCATATGCTGCAGCTAACTT GGCAGGACCACAAACCTTTATTGCTAAGCAGGCTCCTAAATATCATGGCGCTAAGGTCGC TATGGTCGTATGTTATGCTGTTATGATCGTGCTTCTATCTATACTGCTCATCGTCAATTT AAGGGAAAACAAGAGACGTGATAAGATAGCTGCCGAGAGAGGGTTCCCTGAAGAAACAGA GAATTTAGAGTTTTCTGATTTGACTGATTTTGAAAATCCAAATTTCAGATACACTTTATG >YKR039W\|GAP1 CCTAGCTGAACAGAGATTTCTGCCAGAAATCTTTTCCTACGTTGACCGTAAGGGTAGACC ATTGGTGGGAATTGCTGTCACATCTGCATTCGGTCTTATTGCGTTTGTTGCCGCCTCCAA AAAGGAAGGTGAAGTTTTCAACTGGTTACTAGCCTTGTCTGGGTTGTCATCTCTATTCAC ATGGGGTGGTATCTGTATTTGTCACATTCGTTTCAGAAAGGCATTGGCCGCCCAAGGAAG AGGCTTGGATGAATTGTCTTTCAAGTCTCCTACCGGTGTTTGGGGTTCCTACTGGGGGTT ATTTATGGTTATTATTATGTTCATTGCCCAATTCTACGTTGCTGTATTCCCCGTGGGAGA TTCTCCAAGTGCGGAAGGTTTCTTCGAAGCTTATCTATCCTTCCCACTTGTTATGGTTAT GTACATCGGACACAAGATCTATAAGAGGAATTGGAAGCTTTTCATCCCAGCAGAAAAGAT GGACATTGATACGGGTAGAAGAGAAGTCGATTTAGATTTGTTGAAACAAGAAATTGCAGA AGAAAAGGCAATTATGGCCACAAAGCCAAGATGGTATAGAATCTGGAATTTCTGGTGTTA ;WARNING invalid query foo ;WARNING invalid query bar ;WARNING invalid query qux [download] Regards, Velusamy R. eval"print uc\"\\c$_\""for split'','j)@,/6%@0%2,`e@3!-9v2)/@\|6%,53!-9@2~j';	[reply] [d/l] [select]
Re^2: Cleaning up a text file with compact regex by chromatic (Archbishop) on Apr 24, 2007 at 17:53 UTC
Just a note: `my @content = <DATA>;` Slurping genomic data into memory may be expensive in time and resources. In this case it may not be an issue, but data sets run large in bioinformatics, so line or chunk processing is often much more feasible.	[reply] [d/l]
Re: Cleaning up a text file with compact regex by Anonymous Monk on Apr 24, 2007 at 06:48 UTC
As you asked for a regex... `$line =~ /^(>.\|[ATCG])$/` the whole line should be captured into $1	[reply] [d/l]
Re: Cleaning up a text file with compact regex by ikegami (Patriarch) on Apr 24, 2007 at 22:19 UTC
`perl -pe "next if $.<7 \|\| /^;/" infile > outfile` [download]	[reply] [d/l]
Re: Cleaning up a text file with compact regex by OfficeLinebacker (Chaplain) on Apr 24, 2007 at 12:32 UTC
To get to the heart of the matter, as it were, your principles: as I understand the relative efficiencies and strengths, one might argue that awk or sed might be the 'right tool for the job.' Note that while I know how I would do this in Perl, there are already several good answers. I do not know, off the top of my head, how to do it in sed or awk. I like computer programming because it's like Legos for the mind.	[reply]