I have a hash like
%has = ('TCA' =>'S', 'TTC'=>'N'....)
and a
$string = 'TCA'
I want to look for my $string in the %has and if it exist, print the value using perl like this:
TCA, S
How can I do that? Thank you so much!
Check if the value exists.
if (exists $has{$string}) {
printf "%s, %s\n", $string, $has{$string};
}
Keep in mind that this is case sensitive.
You should probably read up on the various Perl functions in perldoc perlfunc
Related
The shell script will be passed a string of arguments. The position of the key/value I am looking to parse out may change over time, i.e. it may come before or after another key at any time so parsing between two keys wouldn't be an option.
I am looking to parse the domain key out of a string like this:
maxpark 0 maxsub n domain sample.foo maxlst n max_defer_fail_percentage user oli force no_cache_update 0 maxpop n maxaddon 0 locale en contactemail
The key would be "domain" the value would be "sample.foo". The domain key could have more than one '.' in it so I would need to grab the entire domain key.
I am not the best with regular expressions but I imagine using 'sed' is what I'm going to need to do.
I am accessing this full string using $*, if I could simply reference the key by accessing $DOMAIN that would be great, but since my only option is to access based on position, $3, and the position could change, that isn't an option
Solved the problem using PERL.
#!/usr/bin/perl -w
use strict;
my %OPTS = #ARGV;
open(FILE, "</var/named/$OPTS{'domain'}.db") || die "File not found";
my #lines = <FILE>;
close(FILE);
my #newlines;
foreach(#lines) {
$_ =~ s/$LOCAL_IP/$PUBLIC_IP/g;
push(#newlines,$_);
}
open(FILE, ">/var/named/$OPTS{'domain'}.db") || die "File not found";
print FILE #newlines;
close(FILE);
If you do have perl, just use this one-liner from your shell script.
domain=$( echo $* | perl -ne '/domain\s([^\s]+)\s/ and print "$1"' )
Or if you'd rather just do it with sed:
domain=$( echo $* | sed 's/.*\<domain \([^ ]\+\).*/\1/' )
In my perl script I want to have both versions of $config directory:
my $config='$home/client/config';
and
my $config_resolved="$home/client/config";
But I want to get $config_resolved from $config, i.e. something like this:
my $config_resolved=resolve_vars($config);
How can I do such thing in perl?
From the Perl FAQ (which every Perl programmer should read at least once):
How can I expand variables in text strings?
(contributed by brian d foy)
If you can avoid it, don't, or if you can
use a templating system, such as Text::Template or Template Toolkit,
do that instead. You might even be able to get the job done with
sprintf or printf:
my $string = sprintf 'Say hello to %s and %s', $foo, $bar;
However, for the one-off simple case where I don't want to pull out a
full templating system, I'll use a string that has two Perl scalar
variables in it. In this example, I want to expand $foo and $bar to
their variable's values:
my $foo = 'Fred';
my $bar = 'Barney';
$string = 'Say hello to $foo and $bar';
One way I can do this involves the substitution operator and a double /e flag. The
first /e evaluates $1 on the replacement side and turns it into $foo. The
second /e starts with $foo and replaces it with its value. $foo,
then, turns into 'Fred', and that's finally what's left in the string:
$string =~ s/(\$\w+)/$1/eeg; # 'Say hello to Fred and Barney'
The /e will also silently ignore violations of strict, replacing undefined
variable names with the empty string. Since I'm using the /e flag
(twice even!), I have all of the same security problems I have with
eval in its string form. If there's something odd in $foo, perhaps
something like #{[ system "rm -rf /" ]}, then I could get myself in
trouble.
To get around the security problem, I could also pull the
values from a hash instead of evaluating variable names. Using a
single /e, I can check the hash to ensure the value exists, and if it
doesn't, I can replace the missing value with a marker, in this case
??? to signal that I missed something:
my $string = 'This has $foo and $bar';
my %Replacements = (
foo => 'Fred',
);
# $string =~ s/\$(\w+)/$Replacements{$1}/g;
$string =~ s/\$(\w+)/
exists $Replacements{$1} ? $Replacements{$1} : '???'
/eg;
print $string;
I use eval for this.
So, you must replace all scalars (their names) with their values.
$config = 'stringone';
$boo = '$config/any/string';
$boo =~ s/(\$\w+)/eval($1)/eg;
print $boo;
Because you are using my to declare it as private variable, you might as well use a /ee modifier. This can find variables declared to be in local scope:
$boo =~ s/(\$\w+)/$1/eeg;
This is most tidily and safely done by the double-eval modifier on s///.
In the program below, the first /e evaluates the string $1 to get $home, while the second evaluates $home to get the variable's value HOME.
use strict;
my $home = 'HOME';
my $config = '$home/client/config';
my $config_resolved = resolve_vars($config);
print $config_resolved, "\n";
sub resolve_vars {
(my $str = shift) =~ s/(\$\w+)/$1/eeg;
return $str;
}
output
HOME/client/config
I've tried searching through questions already asked, but can't seem to find anything. I'm sure its incredibly simple to do, but I am completely new to Perl.
What I am trying to do is remove characters in an string up to a certain point. For example, I have:
Parameter1 : 0xFFFF
and what I would like to do is remove the "Parameter1:" and be left with just the "0xFFFF". If anyone can help and give a simple explanation of the operators used, that'd be great.
Sounds like you need the substr function.
#!/usr/bin/perl
use strict;
use warnings;
my $string = 'Parameter1 : 0xFFFF';
my $fragment = substr $string, 12;
print " string: <$string>\n";
print "fragment: <$fragment>\n";
s/.*:\s*//;
or
$s =~ s/.*:\s*//;
This deletes everything up to and including the first occurrence of : followed by zero or more whitespace characters. With $s =~ it's applied to $s; without it, it's applied to $_.
Have you considered using something like Config::Std?
Here is how to parse a configuration file like that by hand:
#!/usr/bin/perl
use strict; use warnings;
my %params;
while ( my $line = <DATA> ) {
if ($line =~ m{
^
(?<param> Parameter[0-9]+)
\s*? : \s*?
(?<value> 0x[[:xdigit:]]+)
}x ) {
$params{ $+{param} } = $+{value};
}
}
use YAML;
print Dump \%params;
__DATA__
Parameter1 : 0xFFFF
Parameter3 : 0xFAFF
Parameter4 : 0xCAFE
With Config::Std:
#!/usr/bin/perl
use strict; use warnings;
use Config::Std;
my $config = do { local $/; <DATA> };
read_config \$config, my %params;
use YAML;
print Dump \%params;
__DATA__
Parameter1 : 0xFFFF
Parameter3 : 0xFAFF
Parameter4 : 0xCAFE
Of course, in real life, you'd pass a file name to read_config instead of slurping it.
I like split for these parameter/value pairs.
my $str = "Parameter1 : 0xFFFF";
my ($param, $value) = split /\s*:\s*/, $str, 2;
Note the use of LIMIT in the split, which limits the split to two fields (in case of additional colons in the value).
I have this in perl
return "$file->{srv_cgi_url}/dl.cgi/$hash/$fname";
where
$file->{srv_cgi_url}
returns
http://s1.site.com/cgi-bin/
how can I remove the trailing /cgi-bin/ from the string? :)
Thanks!
Like this:
my $new = $file->{srv_cgi_url};
$new =~ s{/cgi-bin/}{};
That is all. See perldoc perlre for details.
While substitution can work, it’s fragile and difficult to extend and maintain. I strenuously recommend learng to use URI, URI::QueryParam, and Path::Class instead (the last is not used in this example but important and related).
use warnings;
use strict;
use URI;
my $file;
$file->{srv_cgi_url} = "http://s1.site.com/cgi-bin/";
my $srv_cgi_uri = URI->new( $file->{srv_cgi_url} );
my $hash = "some";
my $fname = "path.ext";
$srv_cgi_uri->path("/dl.cgi/$hash/$fname");
print $srv_cgi_uri, "\n";
__END__
http://s1.site.com/dl.cgi/some/path.ext
I need to convert a name in the format Parisi, Kenneth into the format kparisi.
Does anyone know how to do this in Perl?
Here is some sample data that is abnormal:
Zelleb, Charles F.,,IV
Eilt, John,, IV
Wods, Charles R.,,III
Welkt, Craig P.,,Jr.
These specific names should end up as czelleb, jeilt, cwoods, cwelkt, etc.
I have one more condition that is ruining my name builder
O'Neil, Paulso far, Vinko Vrsalovic's answer is working the best when weird/corrupt names are in the mix, but this example above would come out as "pneil"... id be damned below judas if i cant get that o between the p and the n
vinko#parrot:~$ cat genlogname.pl
use strict;
use warnings;
my #list;
push #list, "Zelleb, Charles F.,,IV";
push #list, "Eilt, John,, IV";
push #list, "Woods, Charles R.,,III";
push #list, "Welkt, Craig P.,,Jr.";
for my $name (#list) {
print gen_logname($name)."\n";
}
sub gen_logname {
my $n = shift;
#Filter out unneeded characters
$n =~ s/['-]//g;
#This regex will grab the lastname a comma, optionally a space (the
#optional space is my addition) and the first char of the name,
#which seems to satisfy your condition
$n =~ m/(\w+), ?(.)/;
return lc($2.$1);
}
vinko#parrot:~$ perl genlogname.pl
czelleb
jeilt
cwoods
cwelkt
I would start by filtering the abnormal data so you only have regular names. Then something like this should do the trick
$t = "Parisi, Kenneth";
$t =~ s/(.+),\s*(.).*/\l$2\l$1/;
Try:
$name =~ s/(\w+),\s(\w)/$2$1/;
$name = lc $name;
\w here matches an alphanumerical character. If you want to be more specific, you could also use [a-z] instead, and pass the i flag (case insensitive):
$name =~ s/([a-z]+)\s([a-z])/$2$1/i;
Here's a one line solution, assuming you store all the names in a file called "names" (one per line) and you will do duplicated name detection somehow later.
cat names | perl -e 'while(<>) {/^\s*(\S*)?,\s*(\S)/; print lc "$2$1\n";}' | sed s/\'//g
It looks like your input data is comma-separated. To me, the clearest way to do this would be split into components, and then generate the login names from that:
while (<>) {
chomp;
my ($last, $first) = split /,/, lc $_;
$last =~ s/[^a-z]//g; # strip out nonletters
$first =~ s/[^a-z]//g; # strip out nonletters
my $logname = substr($first, 0, 1) . $last;
print $logname, "\n";
}
$rowfetch =~ s/['-]//g; #All chars inside the [ ] will be filtered out.
$rowfetch =~ m/(\w+), ?(.)/;
$rowfetch = lc($2.$1);
this is how I ended up using Vinko Vrsalovic's solution... its inside a while loop that goes through a sql query result ... thanks again vinko
This should do what you need
use strict;
use warnings;
use 5.010;
while ( <DATA> ) {
say abbreviate($_);
}
sub abbreviate {
for ( #_ ) {
s/[-']+//g;
tr/A-Z/a-z/;
tr/a-z/ /c;
return "$2$1" if /([a-z]+)\s+([a-z])/;
}
}
__DATA__
Zelleb, Charles F.,,IV
Eilt, John,, IV
Woods, Charles R.,,III
Welkt, Craig P.,,Jr.
O'Neil, Paul
output
czelleb
jeilt
cwoods
cwelkt
poneil