Author:
erics, August 4th, 2019
I wanted to call a sub-routine based on a variable in Perl, like this:
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our $role = 'master'; &$role; |
but it failed because of use strict:
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Can't use string ("master") as a subroutine ref while "strict refs" in use at /opt/continuent/tungsten/tools/tungsten_find_orphaned line 213. |
To enable using a variable as a reference, simply specify that to Perl:
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use strict no strict "refs"; |
Categories: How-To's, Technology Tags: de-reference, dereference, howto, no strict, perl, Reference, Strict, Subroutine, tips, Variable
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Author:
erics, June 12th, 2019
The Problem Tried to install the latest version of cpan and got stuck. Tracked it down to the dependency module Mac::SystemDirectory which was failing to build:
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cpan[1]> install Mac::SystemDirectory Reading '/var/root/.cpan/Metadata' Database was generated on Sun, 09 Jun 2019 07:17:02 GMT Running install for module 'Mac::SystemDirectory' Running make for E/ET/ETHER/Mac-SystemDirectory-0.10.tar.gz Checksum for /var/root/.cpan/sources/authors/id/E/ET/ETHER/Mac-SystemDirectory-0.10.tar.gz ok Scanning cache /var/root/.cpan/build for sizes ............................................................................DONE CPAN.pm: Building E/ET/ETHER/Mac-SystemDirectory-0.10.tar.gz HASCOMPILEREZFt/TESTUSSI.c:2:10: fatal error: 'EXTERN.h' file not found #include "EXTERN.h" ^~~~~~~~~~ 1 error generated. Couldn't execute cc -g -pipe -fno-common -DPERL_DARWIN -fno-strict-aliasing -fstack-protector -Os "-I/System/Library/Perl/5.18/darwin-thread-multi-2level/CORE" -c HASCOMPILEREZFt/TESTUSSI.c -o HASCOMPILEREZFt/TESTUSSI.o: Inappropriate ioctl for device at Makefile.PL line 14. Requires a compiler Warning: No success on command[/usr/bin/perl Makefile.PL INC=-I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Perl/5.18/darwin-thread-multi-2level/CORE] ETHER/Mac-SystemDirectory-0.10.tar.gz /usr/bin/perl Makefile.PL INC=-I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Perl/5.18/darwin-thread-multi-2level/CORE -- NOT OK Running make test Make had some problems, won't test Running make install Make had some problems, won't install Failed during this command: ETHER/Mac-SystemDirectory-0.10.tar.gz : writemakefile NO '/usr/bin/perl Makefile.PL INC=-I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Perl/5.18/darwin-thread-multi-2level/CORE' returned status 6400 |
The Solution Use the MacOS installer command to deploy the needed files:
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sudo installer -pkg /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg -target / installer: Package name is macOS_SDK_headers_for_macOS_10.14 installer: Installing at base path / installer: The install was successful. |
The, rerunning the cpan install works:
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cpan[1]> install Mac::SystemDirectory ... Running make install Files found in blib/arch: installing files in blib/lib into architecture dependent library tree Installing /Library/Perl/5.18/darwin-thread-multi-2level/auto/Mac/SystemDirectory/SystemDirectory.bs Installing /Library/Perl/5.18/darwin-thread-multi-2level/auto/Mac/SystemDirectory/SystemDirectory.bundle Installing /Library/Perl/5.18/darwin-thread-multi-2level/Mac/SystemDirectory.pm Installing /usr/local/share/man/man3/Mac::SystemDirectory.3pm Appending installation info to /Library/Perl/Updates/5.18.2/darwin-thread-multi-2level/perllocal.pod ETHER/Mac-SystemDirectory-0.10.tar.gz /usr/bin/make install -- OK |
Categories: How-To's, Technology Tags: 10.14, CPAN, Error, extern.h, Fatal, Fatal Error, File not found, Header, headers, howto, Install, installer, Libraries, Library, MacOS, Mojave, not found, Package, perl, pkg, System, tips, update, upgrade, XCode
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Author:
erics, May 31st, 2019
I have a task in Perl to list specific files based on pattern match, those with and those without the string “_from_”. There are two files in the directory to filter: static-east.properties static-east_from_west.properties To capture the files with the _from_ string was easy:
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/^static-(.*?)_from_(.*?)\.properties$/ |
To capture the files WITHOUT the _from_ string was not quite […]
Categories: How-To's, Technology Tags: exclude, howto, Lookahead, Negative, Negative Lookahead, perl, Regex, tips, without
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Author:
erics, January 11th, 2019
In the normal vim mode, typing gg=G will reindent the entire file. == will re-indent just the current line. http://vim.wikia.com/wiki/Fix_indentation
Categories: How-To's, Technology Tags: Auto-indent, Format, howto, Indent, perl, re-indent, Reformat, tips, vi, vim
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Author:
erics, September 18th, 2017
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my $created_at = '2017-09-18T13:43:40Z'; my $marker = DateCalc('today','30 days ago'); my $cmp = Date_Cmp($created_at,$marker); if ($cmp < 0) { print "Older than marker!\n"; } else { print "Same date or later than marker\n"; } |
Categories: How-To's, Technology Tags: Calc, Date, Date::Manip, Delta, howto, perl, tips
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Author:
erics, September 5th, 2017
Step 1: Enable Apache status and lock it down: Make sure mod_status is being loaded:
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shell> grep -Rn mod_status /etc/httpd/* /etc/httpd/conf.modules.d/00-base.conf:58:LoadModule status_module modules/mod_status.so |
Add support for the call just under the first DocumentRoot statement:
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shell> vim /etc/httpd/conf/httpd.conf <Location /server-status> SetHandler server-status Require ip 127.0.0.1 Require ip ::1 Require ip {Your_IP_Here} </Location> |
Step 2. Prepare your environment:
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shell> cpan YAML HTML::TableExtract |
Step 3: Create and run the status script: (See the astat contents at the bottom)
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shell> vim /root/astat shell> chmod 755 /root/astat shell> vi ~/.bashrc ADD: alias ipw='while true; do sleep 5; /root/astat; done' shell> ipw 1.2.3.4|yourdomain.com:443|POST /wp-cron.php?doing_wp_cron=1563901063.57946491241455078125| |
/root/astat
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#!/usr/bin/perl use strict; use HTML::TableExtract; # PATH to "curl" utility my $CURL = "/usr/bin/curl"; # URL of the server-status we want to process my $STATUS_URL = "http://localhost/server-status"; # those are the headers in the first row of the table we want to extract # Used by HTML::TableExtract to search for our table, within the whole HTML output my $headers =['Srv','PID','Acc','M','CPU','SS','Req','Conn','Child','Slot','Client','VHost','Request']; # Let's fetch the status page... my $output = `$CURL -s $STATUS_URL`; # Let's search for our table within the HTML... my $tables = HTML::TableExtract->new( headers => $headers ); # We found it (hopefully), so let's parse it... $tables->parse($output); # ...and let's stick to the first one my $status_table = $tables->first_table_found; # Now let's loop allover the rows... foreach my $row_ref ($status_table->rows) { # Let's de-reference the ARRAY reference, so to better manager # the various elements... my @row = @$row_ref; # Let's check for IP next if $row[10]=~/127.0.0.1/; next if $row[10]=~/216.66.125.161/; next if $row[10]=~/69.162.124.235/; # Let's check for an OPTIONS row... if ($row[12]=~/OPTIONS/) { # simply skip to next row in the loop next; } # Let's choose whatever columns we want (first column has index "0") # So here we have Srv, PID, Client and Request #foreach my $column (0,1,10,12) { foreach my $column (10,11,12) { print $row[$column]."|"; } print "\n"; } |
Categories: How-To's, Technology Tags: 2.4, apache, Apache 2.4, CPAN, howto, http, httpd, https, mod_status, perl, Status, tips, YAML
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Author:
erics, October 16th, 2014
Using PERL, we can easily do a search and replace across multiple files. perl -pi -w -e ‘s/SEARCH_FOR/REPLACE_WITH/g;’ FILE_LIST The following example will replace all occurrences of “hello” with “goodbye” inside files ending with .txt:
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perl -pi -w -e 's/hello/goodbye/g;' *.txt |
To handle special characters, use the hex value. For example, to convert MS web files that use control characters: […]
Categories: How-To's, Technology Tags: Batch, howto, perl, Replace, search, tips
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Author:
erics, March 19th, 2014
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use Getopt::Long qw(:config no_ignore_case); |
Categories: How-To's, Technology Tags: Arg, Args, Case, Case sensitive, cli, Getopt, Getopt::Long, howto, no_ignore_case, option, perl, Sensitive, tips
| No comments
Author:
erics, December 26th, 2013
CPAN Error: Undefined subroutine &IO::Uncompress::Base::readonly called at /usr/lib/perl5/site_perl/5.8.8/IO/Uncompress/Base.pm Looks like CentOS update installs an older version of the Scalar::Util so that Perl could not load the module. Download the Scalar::Util module and manually install it:
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wget http://search.cpan.org/CPAN/authors/id/P/PE/PEVANS/Scalar-List-Utils-1.35.tar.gz tar xvzf Scalar-List-Utils-*.tar.gz cd Scalar-List-Utils-* perl Makefile.PL gmake gmake test gmake install |
To test: perl -MCPAN -e ‘shell’ For more information, visit the CPAN Util.pm page. Original Post: http://www.perlmonks.org/?displaytype=print;node_id=965635;replies=1
Categories: How-To's, Technology Tags: CPAN, howto, IO, IO::Uncompress, perl, Scalar, Scalar::Utils, tips, Uncompress, Utils
| 1 comment
Author:
erics, April 13th, 2012
I had to patch the distribution by adding the following variable into the code: $Config::Auto::Untaint = 1; Here is the fix on AWS Linux: vim /usr/local/share/perl5/CGI/Application/Plugin/ConfigAuto.pm 141 sub cfg { 142 my $self = shift; 143 144 if (!$self->{__CFG}) { 145 require Config::Auto; 146 $Config::Auto::Untaint = 1; (ADD THIS NEW LINE HERE)
Categories: How-To's, Technology Tags: AWS, AWS Linux, CGI::Application::Plugin::ConfigAuto, Config::Auto, howto, Linux, perl, Taint, Taint Mode, tips
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