This question already has an answer here:
Closed 12 years ago.
Possible Duplicate:
How do I change, delete, or insert a line in a file, or append to the beginning of a file in Perl?
How would I use perl to open up a file, look for an item that someone inputs, and if it is found, it will delete from that line to 14 lines below.
Something like this will work:
#!/usr/bin/env perl
use Modern::Perl;
use IO::File;
say "Enter a pattern please: ";
chomp (my $input = <>);
my $pattern;
# check that the pattern is good
eval {
$pattern = qr ($input);
}; die $# if $#;
my $fh = IO::File->new("test.txt", "+<") or die "$!\n";
my #lines = $fh->getlines;
$fh->seek(0,0);
for (my $pos = 0; $pos < $#lines; ++$pos) {
if ($lines[$pos] =~ $pattern) {
$pos += 14;
} else {
print {$fh} $lines[$pos];
}
}
$fh->close;
$|++
#!/usr/bin/env perl
use strict;
use warnings;
use autodie;
my $filename = 'filename.txt';
my $tmp = 'filename.txt.tmp';
print "Enter a pattern please: ";
chomp (my $input = <>);
my $pattern = qr($input)x;
open my $i_fh, '+<', $filename;
open my $o_fh, '>', $tmp;
while(<$i_fh>){
# move print here if you want to print the matching line
if( /$pattern/ ){
<$i_fh> for 1..14;
next;
}
print {$o_fh} $_ ;
}
close $o_fh;
close $i_fh;
use File::Copy
move $tmp, $filename;
Related
I want to write a perl script that ask the user for a string and then finds the lines that contains that string and prints them.
This is what i have so far
#!/usr/bin/perl
use strict;
use warnings;
sub main
{
print "First name or Last Name or any portion: ";
my $name = <STDIN>;
my $file = '/home/jake/Downloads/phones';
open(FH, $file) or die("File $file not found");
while(my $String = <FH>)
{
if($String =~ $name)
{
print "$String \n";
}
}
close(FH);
}
main();
Whenever I try this the terminal doesnt print anything. Is there anything that I could do to fix that?
Try this out:
#!/usr/bin/perl
use strict;
use warnings;
sub main
{
print "First name or Last Name or any portion: ";
my $name = <STDIN>;
chomp $name;
my $file = '/home/jake/Downloads/phones';
open my $fh, '<', $file or die "$file: $!\n";
while(my $string = <$fh>)
{
if($string =~ /$name/)
{
print "$string\n";
}
}
close($fh);
}
main();
You need to omit the new line character using chomp.
Use a modern way to read a file, using a lexical filehandle.
I have a big fasta file input.fasta which consists many duplicate sequences. I want to enter a header name and extract out all the sequences with the matching header. I know this could be done easily done with awk/sed/grep but I need a Perl code.
input.fasta
>OGH38127_some_organism
PAAALGFSHLARQEDSALTPKHYTWTAPGEGDVRAPCPVLNTLANHEFLPHNGKNITVDK
AITALGDAMNISPALATTFFTGGLKTNPTPNATWFDLDMLHKHNVLEHDGSLSRRDMHFD
TSNKFDAATFANFLSYFDANATVLGVNETADARARHAYDMSKMNPEFTITSSMLPIMVGE
SVMMMLVWGSVEEPGAQRDYFEYFFRNERLPVELGWTPGETEIGVPVVTAMITAMVAASP
TDVP
>ABC14110_some_different_org_name
WWVAPGPGDSRGPCPGLNTLANHGYLPHDGKGITLSILADAMLDGFNIARSDALLLFTQ
AIRTSPQYPATNSFNLHDLGRDQLNRHNVLEHDASLSRADDFFGSNHIFNETVFDESRAY
AMLANSKIARQINSKAFNPQYKFTSKTEQFSLGEIAAPIIAFGNSTSGEVNRTLVEYFFM
NERLPIELGWKKSEDGIALDDILRVTQMISKAASLITPSALSWTAETLTP
>OGH38127_some_organism
LPWSRPGPGAVRAPCPMLNTLANHGFLPHDGKNISEARTVQALGRALNIEKELSQFLFEK
ALTTNPHTNATTFSLNDLSRHNLLEHDASLSRQDAYFGDNHDFNQTIFDETRSYWPHPVI
DIQAAALSRQARVNTSIAKNPTYNMSELGLDFSYGETAAYILILGDKDFGKVNRSWVEYL
FENERLPVELGWTRHNETITSDDLNTMLEKVVN
.
.
.
I have tried with the following script but it is not giving any output.
script.pl
#!/perl/bin/perl -w
use strict;
use warnings;
print "Enter a fasta header to search for:\n";
my $head = <>;
my $file = "input.fasta";
open (READ, "$file") || die "Cannot open $file: $!.\n";
my %seqs;
my $header;
while (my $line = <READ>){
chomp $line;
$line =~ s/^>(.*)\n//;
if ($line =~ m/$head/){
$header = $1;
}
}
close (READ);
open( my $out , ">", "out.fasta" ) or die $!;
my #count_seq = keys %seqs;
foreach (#count_seq){
print $out $header, "\n";
print $out $seqs{$header}, "\n";
}
exit;
Please help me correct this script.
Thanks!
If you use the Bioperl module Bio::SeqIO to handle the parsing of the fasta files, it becomes really simple:
#!/usr/bin/perl
use warnings;
use strict;
use Bio::SeqIO;
my ($file, $name) = #ARGV;
my $in = Bio::SeqIO->new(-file => $file, -format => "fasta");
my $out = Bio::SeqIO->new(-fh => \*STDOUT, -format => "fasta");
while (my $s = $in->next_seq) {
$out->write_seq($s) if $s->display_id eq $name;
}
run with perl grep_fasta.pl input.fasta OGH38127_some_organism
There's no need to store the sequences in memory, you can print them directly when reading the file. Use a flag variable ($inside in the example) that tells you whether you're reading the desired sequence or not.
#! /usr/bin/perl
use warnings;
use strict;
my ($file, $header) = #ARGV;
my $inside;
open my $in, '<', $file or die $!;
while (<$in>) {
$inside = $1 eq $header if /^>(.*)/;
print if $inside;
}
Run as
perl script.pl file.fasta OGH38127_some_organism > output.fasta
Here I have a abc.txt file:
aaa,1000,kevin
bbb,2000,john
ccc,3000,jane
ddd,4000,kevin
Then I want to print out:
kevin
john
jane
my Perl script is:
open (INFILE, $ARGV[1]) or die "An input file is required as argument\n";
#store=();
while(<INFILE>)
{
chomp();
#data=split(/,/);
#
#
#
if (%store ne "0")
{
print "Printing users:\n";
foreach $key (keys %store)
{print $key."\n";}
}
print "Printing users:\n";
foreach $key (keys %store)
{print $key."\n";}
}
My idea is to store the value into hash and create key to each value. How can I do in the ### line?
You have declared #store and then using %store. I didn't understand that why you doing that, but the below code will give you desire output. First read the input file, split the data and then remove the duplicates.
use strict;
use warnings;
my $infile = $ARGV[0];
open my $fh, "<", $infile or die "An input file is required as argument: $!";
my %store;
while(my $line = <$fh>)
{
chomp($line);
my #data = split /,/, $line;
my #removeduplicate = (grep { !$store{$_}++ } #data)[2];
foreach(#removeduplicate){
if( $_ ne ''){
print "$_\n";
}
}
}
close $fh;
Output:
kevin
john
jane
hmmm. it depends what do you want. maybe this example will help you:
#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper; #for debug if you want
my $infile='abc.txt'; #or ARGV[0] whatever it is
my $fh;
open $fh,'<',$infile or die "problem with $infile $# $!";
my $inputline;
my %Storage;
my #Values;
while (defined($inputline=<$fh>)) {
chomp $inputline;
#Values=split ',',$inputline;
if (#Values != 3) {
warn "$inputline has formatted badly";
next;
}
#warn if exists $Storage{$Values[1]}; #optional warning for detected duplicates
$Storage{$Values[1]}=#Values[0,2]; #create hash data
#duplicates will be removed automaticly
}
close $fh;
print Dumper \%Storage; #print how perl it stores
foreach my $Key (keys %Storage) { #example loop
print #{Storage->{$Key}},"\n"; #do anything
}
I hope this template will be enough for you.
This question already has answers here:
Counting number of occurrences of a string inside another (Perl)
(4 answers)
Closed 7 years ago.
I have to check how many times was "," in each line in file. Anybody have idea how can I do it in Perl?
On this moment my code looks like it:
open($list, "<", $student_list)
while ($linelist = <$list>)
{
printf("$linelist");
}
close($list)
But I have no idea how to check how many times is "," in each $linelist :/
Use the transliteration operator in counting mode:
my $commas = $linelist =~ y/,//;
Edited in your code :
use warnings;
use strict;
open my $list, "<", "file.csv" or die $!;
while (my $linelist = <$list>)
{
my $commas = $linelist =~ y/,//;
print "$commas\n";
}
close($list);
If you just want to count the number of somethings in a file, you don't need to read it into memory. Since you aren't changing the file, mmap would be just fine:
use File::Map qw(map_file);
map_file my $map, $filename, '<';
my $count = $map =~ tr/,//;
#! perl
# perl script.pl [file path]
use strict;
use warnings;
my $file = shift or die "No file name provided";
open(my $IN, "<", $file) or die "Couldn't open file $file: $!";
my #matches = ();
my $index = 0;
# while <$IN> will get the file one line at a time rather than loading it all into memory
while(<$IN>){
my $line = $_;
my $current_count = 0;
# match globally, meaning keep track of where the last match was
$current_count++ while($line =~ m/,/g);
$matches[$index] = $current_count;
$index++;
}
$index = 0;
for(#matches){
$index++;
print "line $index had $_ matches\n"
}
You can use mmap Perl IO layer instead of File::Map. It is almost as efficient as former but most probably present in your Perl installation without needing installing a module. Next, using y/// is more efficient than m//g in array context.
use strict;
use warnings;
use autodie;
use constant STUDENT_LIST => 'text.txt';
open my $list, '<:mmap', STUDENT_LIST;
while ( my $line = <$list> ) {
my $count = $line =~ y/,//;
print "There is $count commas at $.. line.\n";
}
If you would like grammatically correct output you can use Lingua::EN::Inflect in the right place
use Lingua::EN::Inflect qw(inflect);
print inflect "There PL_V(is,$count) $count PL_N(comma,$count) at ORD($.) line.\n";
Example output:
There are 7 commas at 1st line.
There are 0 commas at 2nd line.
There is 1 comma at 3rd line.
There are 2 commas at 4th line.
There are 7 commas at 5th line.
Do you want #commas for each line in the file, or #commas in the entire file?
On a per-line basis, replace your while loop with:
my #data = <list>;
foreach my $line {
my #chars = split //, $line;
my $count = 0;
foreach my $c (#chars) { $count++ if $c eq "," }
print "There were $c commas\n";
}
This gives the whole line:
#!/usr/bin/perl
$file = 'output.txt';
open(txt, $file);
while($line = <txt>) {
print "$line" if $line =~ /_NN/;
}
close(txt);
#!/usr/bin/perl
use strict;
use warnings FATAL => "all";
binmode(STDOUT, ":utf8") || die;
my $file = "output.txt";
open(TEXT, "< :utf8", $file) || die "Can't open $file: $!";
while(<TEXT>) {
print "$1\n" while /(\w+)_NN\b/g;
}
close(TEXT) || die "Can't close $file: $!";
Your answer script reads a bit awkwardly, and has a couple of potential errors. I'd rewrite the main logic loop like so:
foreach my $line (grep { /expend_VB/ } #sentences) {
my #nouns = grep { /_NN/ } split /\s+/, $line;
foreach my $word (#nouns) {
$word =~ s/_NN//;
print "$word\n";
}
print "$line\n" if scalar(#nouns);
}
You need to put the my declaration inside the loop - otherwise it will persist longer than you want it to, and could conceivably cause problems later.
foreach is a more common perl idiom for iterating over a list.
print "$1" if $line =~ /(\S+)_NN/;
#!/usr/bin/perl
use strict;
use warnings FATAL => "all";
my $search_key = "expend"; ## CHANGE "..." to <>
open(my $tag_corpus, '<', "ch13tagged.txt") or die $!;
my #sentences = <$tag_corpus>; # This breaks up each line into list
my #words;
for (my $i=0; $i <= #sentences; $i++) {
if ( defined( $sentences[$i] ) and $sentences[$i] =~ /($search_key)_VB.*/i) {
#words = split /\s/,$sentences[$i]; ## \s is a whitespace
for (my $j=0; $j <= #words; $j++) {
#FILTER if word is noun:
if ( defined( $words[$j] ) and $words[$j] =~ /_NN/) {
#PRINT word and sentence:
print "**",split(/_\S+/,$words[$j]),"**", "\n";
print split(/_\S+/,$sentences[$i]), "\n"
}
} ## put print sentences here to print each sentence after all the nouns inside
}
}
close $tag_corpus || die "Can't close $tag_corpus: $!";