Folks,
I have a bit of an issue trying to obtain some data from a csv file using PERL. I can sort the file and remove any duplicates leaving only 4 or 5 rows containing data. My problem is that the data contained in the original file contains a lot more columns and when I try ro run this script... (13 Replies)
Hi,
I have a .csv file which contains script names, subjects and email_addresses
The first two colums are always script name and subject, the next 20 colums are email address..
What i want to do is sort the email address in alphabetical order for each row and there's around 1200 rows.
So... (3 Replies)
Hi all,
in my csv file it'll look like this, and of course it may have more columns
US to UK;abc-hq-jcl;multimedia
UK to CN;def-ny-jkl;standard
DE to DM;abc-ab-klm;critical
FD to YM;la-yr-tym;standard
HY to MC;la-yr-ytm;multimedia
GT to KJ;def-ny-jrt;critical
I would like to group... (4 Replies)
Hi,
Please help me to solve sorting in CSV file.
I have 25 columns in my CSV. (Delimiter is ",")
Summary columns are from 10 to 13 which are should not be sorted. From 1-9 and 14-25 should be able to sort in ascending. how should i do this using Sort command in unix.
If no simple commands pls... (0 Replies)
Hi everyone,
i am new to perl programming, i have a problem in extracting single column from csv file. the column is the 20th column,
please help me..
at present i use this code
#!C:/perl/bin
use warnings;
use strict;
my $file1 = $ARGV;
open FILE1, "<$file1"
or die "Can't... (13 Replies)
Hi,
I have a CSV file in following manner:
server1,env1,patch1
server1,env1,patch2
server1,env1,patch3
server1,env2,patch1
server1,env2,patch3
server2,env3,patch1
server2,env3,patch5
server2,env4,patch1
server3,env6,patch1
server3,env7,patch2
server3,env7,patch3
I want to... (6 Replies)
Hello all, I am new here and *relatively* new to Unix. I have a bit of an emergency. I have a three column file that I need to sort:
sample name, miRNA, reads per million (RPM)
There are multiple samples, and for each sample name there are multiple miRNAs and associated RPMs. Some of these... (6 Replies)
Hello!
So ive been presented with this comma-delimited file:
I need a print to look as below
"
lastname, phone_number, zip
for every person with a last name starting with the letter H, I
only with a 650-area code phone number. output should be sorted by reverse ZIP code "
I only have... (5 Replies)
I have absolutaly no idea how to get this script to sort the info in Birthdays.csv by date of birth. I know the sort -n command, however i wish to sort the file birthdays.csv by DOB. How would i go about doing this?
The below script gets user info and date of birth and then puts these info a... (3 Replies)
we have a CSV which i need to convert to XML using Perl or Unix shell scripting.
I was able to build this XML in oracle database. However, SQL/XML query is running for long time. Hence, I'm considering to write a Perl or shell script to generate this XML file. Basically need to build this XML... (3 Replies)
Discussion started by: laknar
3 Replies
LEARN ABOUT REDHAT
perldbmfilter
PERLDBMFILTER(1) Perl Programmers Reference Guide PERLDBMFILTER(1)NAME
perldbmfilter - Perl DBM Filters
SYNOPSIS
$db = tie %hash, 'DBM', ...
$old_filter = $db->filter_store_key ( sub { ... } ) ;
$old_filter = $db->filter_store_value( sub { ... } ) ;
$old_filter = $db->filter_fetch_key ( sub { ... } ) ;
$old_filter = $db->filter_fetch_value( sub { ... } ) ;
DESCRIPTION
The four "filter_*" methods shown above are available in all the DBM modules that ship with Perl, namely DB_File, GDBM_File, NDBM_File,
ODBM_File and SDBM_File.
Each of the methods work identically, and are used to install (or uninstall) a single DBM Filter. The only difference between them is the
place that the filter is installed.
To summarise:
filter_store_key
If a filter has been installed with this method, it will be invoked every time you write a key to a DBM database.
filter_store_value
If a filter has been installed with this method, it will be invoked every time you write a value to a DBM database.
filter_fetch_key
If a filter has been installed with this method, it will be invoked every time you read a key from a DBM database.
filter_fetch_value
If a filter has been installed with this method, it will be invoked every time you read a value from a DBM database.
You can use any combination of the methods from none to all four.
All filter methods return the existing filter, if present, or "undef" in not.
To delete a filter pass "undef" to it.
The Filter
When each filter is called by Perl, a local copy of $_ will contain the key or value to be filtered. Filtering is achieved by modifying the
contents of $_. The return code from the filter is ignored.
An Example -- the NULL termination problem.
DBM Filters are useful for a class of problems where you always want to make the same transformation to all keys, all values or both.
For example, consider the following scenario. You have a DBM database that you need to share with a third-party C application. The C appli-
cation assumes that all keys and values are NULL terminated. Unfortunately when Perl writes to DBM databases it doesn't use NULL termina-
tion, so your Perl application will have to manage NULL termination itself. When you write to the database you will have to use something
like this:
$hash{"$key "} = "$value " ;
Similarly the NULL needs to be taken into account when you are considering the length of existing keys/values.
It would be much better if you could ignore the NULL terminations issue in the main application code and have a mechanism that automati-
cally added the terminating NULL to all keys and values whenever you write to the database and have them removed when you read from the
database. As I'm sure you have already guessed, this is a problem that DBM Filters can fix very easily.
use strict ;
use warnings ;
use SDBM_File ;
use Fcntl ;
my %hash ;
my $filename = "/tmp/filt" ;
unlink $filename ;
my $db = tie(%hash, 'SDBM_File', $filename, O_RDWR|O_CREAT, 0640)
or die "Cannot open $filename: $!
" ;
# Install DBM Filters
$db->filter_fetch_key ( sub { s/ $// } ) ;
$db->filter_store_key ( sub { $_ .= "