...
But what if this field is not the last one in the row. Like this:
field 12345 12345 a
field 12345 a
field 12345 123456 a
...
I guess in this case, your conditions are:
(i) Print the line if the number of fields is less than 3
(ii) If the 3rd field exists, print the line if it does not consist of any digits. Its length does not matter here.
(iii) If the 3rd field exists, print the line if it consists ONLY of digits and has a length of 5 or less.
(iv) There can be more than 3 fields, and the line will be printed as long as rules (ii) and (iii) are satisfied.
So for the data below, you want to display lines 1,2,4 and 7:
guys,
my requirment goes like this:
I have a file, and wish to filter out records where
1. The first letter is o or O
and
2. The next 4 following letter should not be ther
I do not wish to use pipe and wish to do it in one shot.
The best expression I came up with is:
grep ^*... (10 Replies)
When i do ls -ld RT_BP* i am getting the following list.
drwxrwx--- 2 user group 256 Oct 17 10:09 RT_BP809
drwxrwx--- 2user group 256 Oct 17 10:09 RT_BP809.O
drwxrwx--- 2 user group 256 Oct 17 10:09 RT_BP810
drwxrwx--- 2user group 256 Oct... (2 Replies)
Hi, guys. I have one question, hope somebody can give me a hand
I have a file called passwd, the contents of it arebelow:
***********************
...
goldsimj:x:5008:200:
goldsij2:x:5009:200:
whitej:x:5010:201:
brownj:x:5011:202:
goldsij3:x:5012:204:
greyp:x:5013:203:
...... (6 Replies)
please can someone tell me what the following regrex means
grep "^aa*$" <file>
I thought this would match any word beginning with aa and ending with $, but it doesnt.
Thanks in advance
Calypso (7 Replies)
Hi,
I am executing a svnlook command to check to see if the following line exists. I need a regular expression to represent the line.
A /test/test1/qa/test2/index.html
A /test/test1/qa/test3/test.jpg
A /test/test1/qa/test3/test1.jpg
A /test/test1/qa/test4/test.swf
I just need to extract... (9 Replies)
Hi all,
How am I read a file, find the match regular expression and overwrite to the same files.
open DESTINATION_FILE, "<tmptravl.dat" or die "tmptravl.dat";
open NEW_DESTINATION_FILE, ">new_tmptravl.dat" or die "new_tmptravl.dat";
while (<DESTINATION_FILE>)
{
# print... (1 Reply)
i have a command line like this in csh script
grep -i "$argv$"
which i wanted to select the line ending with string provided as argument but it couldn't interpret the '$' (ending with)..
any help? (3 Replies)
Hi ,
I have few lines like
A20120101.ANU.ZIP
A20120401.ABC.ZIP
A20120105.KJK.ZIP
A20120809.JUG.ZIP
A20120101.MAT.ZIP
B20120301.ANU.XIP
I want to filter by
1. Files starting with A and Ending With Z ( ^A.*.ZIP$)
2. And either ANU, or KJK or MAT in the file name.
Hope my... (6 Replies)
I want to track only below:
I am using below, but it doesn't work: (6 Replies)
Discussion started by: proactiveaditya
6 Replies
LEARN ABOUT SUSE
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
application assumes that all keys and values are NULL terminated. Unfortunately when Perl writes to DBM databases it doesn't use NULL
termination, 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
automatically 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 = "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 { $_ .= "