I have a file which consists of three names: daniel, elaine and victoria. If I search for daniel I get "you are not on the list". Could someone kindly point out where my mistake is? Thank you.
#!/usr/bin/perl
#open file
open(FILE, "names") or die("Unable to open file");
# read file into an array
#data = <FILE>;
# close file
close(FILE);
print "Enter name\n";
$entry = <STDIN>;
chomp $entry;
if (grep {$_ eq $entry} #data)
{
print "You are on the list $entry";
}
else
{
print "Your are not on the list";
}
You need to chomp (remove new line character from the end of each string) data from the file too:
chomp #data;
if (grep {$_ eq $entry} #data) {
print "You are on the list $entry";
} else {
print "Your are not on the list";
}
change this
if (grep {$_ eq $entry} #data)
to this
if (grep {$_ =~ m/^$entry\b/i} #data)
remove the i if you specifically want it to be case sensitive.
Related
I need a help with the following problem. I have a file with the following data.
21997|||70049,,20170428154818,20170527235959|||
21997|||70070,,20170428154739,20170527235959|||
21998|||70049,,20170428154818,20170527235959|||
21998|||70070,,20170428154739,20170527235959|||
21998|||70071,,20170428154739,20170527235959|||
I need to unify the file as follows.
21997|||70049,,20170502172844,20170531235959; 70070,,20170502172844,20170531235959|||
21998|||70049,,20170502172844,20170531235959; 70070,,20170502172844,20170531235959; 70071,,20170502172844|||
Can someone help me please?
my $unified_output;
my %out;
open(FILE, "./raw-file.txt") or die $!;
my #file = <FILE>;
close FILE;
for (#file) {
next if $_ =~ /$^/;
my #line = split(/\|\|\|/, $_) if $_;
$out{"$line[0]"} .= qq~$line[1]; ~ if $_ and $_ =~ /^$line[0]/;
}
for (keys %out) {
$out{$_} =~ s!\; $!!;
$unified_output .= qq~$_|||$out{$_}|||\n~ if $_ and $out{$_};
}
I have a file with almost 1,500 names of Marvel heroes, each name in new line. I have to ask user what his favourite hero is and find out if it's a hero from the list or not. Here's what I have right now. It doesn't work: I can guess only the last hero from the list. For the rest it just prints that they are not on the list.
print "Whats your favourite hero?\n";
my $hero = <stdin>;
chomp $hero;
open FILE, "<list_marvel.txt";
my #marvel = <FILE>;
chomp(#marvel);
my $result = 0;
foreach (#marvel) {
if ($_ eq $hero);
}
if ($result == 1) {
print "That hero is on the list";
}
else {
print "$hero is not on the list.\n";
}
Here are two files:
-Perl code : Perl Code
-List of heroes : List
Your program has a syntax error and won't compile. It certainly won't find only the last name on the list
The main problem is that you never set $result, and if($_ eq $hero) should be something like $result = 1 if($_ eq $hero)
You must always use strict and use warnings at the top of every Perl program you write. It is an enormous help in finding straighforward problems
Here's a working version
use strict;
use warnings;
my $filename = 'list_marvel.txt';
open my $fh, '<', $filename or die qq{Unable to open "'list_marvel.txt'": $!};
print "Whats your favourite hero? ";
my $hero = <>;
chomp $hero;
my $found;
while ( <$fh> ) {
chomp;
if ( $_ eq $hero ) {
++$found;
last;
}
}
print $found ? "$hero is on the list\n" : "$hero is not on the list";
You don't set $result anywhere to true.
Make your foreach loop like this:
foreach(#marvel){
$result = $_ eq $hero;
}
or
foreach (#marvel){
$result = 1 if $_ eq $hero
}
You forgot to increment your $result. If you indent your code properly, it is easier to see.
foreach (#marvel) {
# here something is missing
if ( $_ eq $hero );
}
Add $result++ if $_ eq $hero; in the foreach.
You should always use strict and use warnings. That would have told you about a syntax error near );.
Also consider using the three argument open with lexical filehandles.
Rewritten it looks like this:
use strict;
use warnings;
use feature 'say'; # gives you say, which is print with a newline at the end
say "What's you favourite hero?";
my $hero = <STDIN>;
chomp $hero;
# alsways name variables so it's clear what they are for
my $found = 0;
# die with the reason of error if something goes wrong
open my $fh, '<', 'list_marvel.txt' or die $!;
# read the file line by line
while ( my $line = <$fh> ) {
chomp $line;
if ( $line eq $hero ) {
# increment so we know we 'found' the hero in the list
$found++;
# stop reading at the first hit
last;
}
}
close $fh;
# no need to check for 1, truth is enough
if ( $result ) {
say "That hero is on the list.";
}
else {
say "$hero is not on the list.";
}
First, you miss setting the $result at around if($_ eq $hero).
Then, you may wish to make you comparison case insensitive. This would require a regular expression, e.g.:
$result = 1 if (/^$hero$/i);
Just modified your code. After if condition increment $result. Always use use strict and use warnings and always use 3 arguments to open a file.
use strict;
use warnings;
print "Whats your favourite hero?\n";
my $hero = <stdin>;
chomp $hero;
open FILE, "<", "list_marvel.txt" or die $!;
chomp (my #marvel = <FILE>);
close FILE;
my $result = 0;
foreach my $name (#marvel)
{
if($name eq $hero)
{
$result++;
}
}
if ($result == 1)
{
print "That hero is in the list.\n";
}
else
{
print "$hero is not in the list.\n";
}
This will take a single user entry from STDIN. It will run through the file of hero names, and if one matches the user entry it will print the name and exit the loop. If the name is not found it will tell you:
use warnings;
use strict;
open my $file1, '<', 'input.txt' or die $!;
print "Enter hero: ";
chomp(my $hero = <STDIN>);
my $result = 0;
while(<$file1>){
chomp;
if (/$hero/){
print "$_\n";
$result++;
last;
}
}
print "hero not in list\n" if $result == 0;
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.
I've noticed that when you drag & drop a file into OS X Terminal and any part of the pathway contains a space (for example in a folder name) it substitutes this for a \
This then leads to an error in opening files in my script:
use strict;
use warnings;
use File::Basename;
my $in;
my $filename = $ARGV[0];
unless ($filename){
print "\n\nPlease drag and drop a FASTA/FA or plain-text file containing your sequence into the prompt window and hit ENTER. Alternatively, manually specify the file-pathway:\n";
$filename = <STDIN>;
chomp $filename;
}
open($in, $filename) or die "Failed to open $in: $!";
my $DNA = read_fasta($in);
my $len = length($DNA);
print "\nFASTA/Sequence Length is: $len bp \n";
print "\nPlease enter restriction sites (degeneracy characters permitted) seperated by a single space: ";
my $sites=<STDIN>;
chomp $sites;
my #pats = split ' ', $sites;
for (#pats) {
s/K/[GT]/g;
s/M/[AC]/g;
s/Y/[CT]/g;
s/S/[CG]/g;
s/W/[AT]/g;
s/B/[CGT]/g;
s/V/[ACG]/g;
s/H/[ACT]/g;
s/D/[AGT]/g;
s/X/[AGCT]/g;
s/R/[AG]/g;
s/N/[AGCT]/g;
}
for (#pats) {
my $m = () = $DNA =~ /$_/gi;
print "\nTotal DNA matches to $_ are: $m \n";
}
my $DIR = dirname($filename);
my $name = basename($filename);
(my $extrem = $name) =~ s/\.[^.]+$//;
open my $out, ">$DIR/$extrem $sites.txt";
my $pat=join("|",#pats);
my #cutarr = split(/$pat/, $DNA);
for (#cutarr) {
my $len = length($_);
print $out "$len \n";
}
print "\nYour results are located at: $DIR/$extrem $sites.txt\n\n";
close($out);
close($in);
#Subfunction - Reading formatted FASTA/FA files
sub read_fasta {
my ($fh) = #_;
my $sequence;
while (<$fh>) {
unless (/^>/) {
chomp;
$sequence .= $_;
}
}
return $sequence;
}
It will open files if the pathway contains no spaces. Is there a better way I can go about opening the file to avoid this occurring?
Try to remove backslashes from your file name,
$filename =~ tr|\\||d;
open(my $in, $filename) or die $!;
I have written the following program with the hope of getting success. But I could never get it.
my $fileName = 'myfile.txt';
print $fileName,"\n";
if (open MYFILE, "<", $fileName) {
my $Data;
{
local $/ = undef;
$Data = <MYFILE>;
}
my #values = split('\n', $Data);
chomp(#values);
if($values[2] eq '9999999999') {
print "Success"."\n";
}
}
The content of myfile.txt is
160002
something
9999999999
700021
Try splitting by \s*[\r\n]+
my $fileName = 'myfile.txt';
print $fileName,"\n";
if (open MYFILE, "<", $fileName) {
my $Data;
{
local $/ = undef;
$Data = <MYFILE>;
}
my #values = split(/\s*[\r\n]+/, $Data);
if($values[2] eq '9999999999') {
print "Success";
}
}
If myfile.txt contain carriage return (CR, \r), it will not work as expected.
Another possible cause is trailing spaces before linefeed (LF, \n).
You don't need to read an entire file into an array to check one line. Open the file, skip the lines you don't care about, then play with the line you do care about. When you've done what you need to do, stop reading the file. This way, only one line is ever in memory:
my $fileName = 'myfile.txt';
open MYFILE, "<", $fileName or die "$filename: $!";
while( <MYFILE> ) {
next if $. < 3; # $. is the line number
last if $. > 3;
chomp;
print "Success\n" if $_ eq '9999999999';
}
close MYFILE;
my $fileName = 'myfile.txt';
open MYFILE, "<", $fileName || die "$fileName: $!";
while( $rec = <MYFILE> ) {
for ($rec) { chomp; s/\r//; s/^\s+//; s/\s+$//; } #Remove line-feed and space characters
$cnt++;
if ( $rec =~ /^9+$/ ) { print "Success\n"; last; } #if record matches "9"s only
#print "Success" and live the loop
}
close MYFILE;
#Or you can write: if ($cnt==3 and $rec =~ /^9{10}$/) { print "Success\n"; last; }
#If record 3 matches ten "9"s print "Success" and live the loop.