Hi,
I have one huge record and know that each record in the file is 550 bytes long. How do I parse out individual records from the single huge record.
Thanks, (4 Replies)
Hi Folks,
I need to compare two very huge file ( i.e the files would contain a minimum of 70k records each) using awk or sed. The comparison needs to be done with respect to a 'key'. For example :
File1
**********
1234|TONY|Y75634|20/07/2008
1235|TINA|XCVB56|30/07/2009... (13 Replies)
Dear friends,
I receive the following files into a FTP location on a daily basis
-rw-r----- 1 guest ftp1 5021 Aug 19 09:03 CHECK_TEST_Extracts_20080818210000.zip
-rw-r----- 1 guest ftp1 2437 Aug 20 05:15 CHECK_TEST_Extracts_20080819210000.zip
-rw-r----- 1 guest ... (2 Replies)
Anyone can help for filter the uniq record for below example? Thank you very much
Input file
20090503011111|test|abc
20090503011112|tet1|abc|def
20090503011112|test1|bcd|def
20090503011131|abc|abc
20090503011131|bbc|bcd
20090503011152|bcd|abc
20090503011151|abc|abc... (8 Replies)
Hi folks,
Below is the content of a file 'tmp.dat', and I want to keep the uniq record (key by first column). However, the uniq record should be the last record.
302293022|2|744124889|744124889
302293022|3|744124889|744124889
302293022|4|744124889|744124889
302293022|5|744124889|744124889... (4 Replies)
I was given a data file that I need to split into multiple lines/records based on a key word. The problem is that it is 2.5GB or bigger and everything I try in perl or sed causes a Segmentation fault. Can someone give me some other ideas.
The data is of the form:... (5 Replies)
Hi,
I have the following command in place
nawk -F, '!a++' file > file.uniq
It has been working perfectly as per requirements, by removing duplicates by taking into consideration only first 3 fields. Recently it has started giving below error:
bash-3.2$ nawk -F, '!a++'... (17 Replies)
Hi,
I have a Huge 7 GB file which has around 1 million records, i want to split this file into 4 files to contain around 250k messages each.
Please help me as Split command cannot work here as it might miss tags..
Format of the file is as below
<!--###### ###### START-->... (6 Replies)
input.csv:
Field1,Field2,Field3,Field4,Field4
abc ,123 ,xyz ,000 ,pqr
mno ,123 ,dfr ,111 ,bbb
output:
Field2,Field4
123 ,000
123 ,111
how to fetch the values of Field4 where Field2='123'
I don't want to fetch the values based on column position. Instead want to... (10 Replies)
I was wondering if anyone could explain to me how to split a variable length EBCDIC file into seperate files based on the record key. I have the COBOL layout, and so I need to split the file into 13 different EBCDIC files so that I can run each one through a C++ converter I have, and get the... (11 Replies)
Discussion started by: hanshot1stx
11 Replies
LEARN ABOUT DEBIAN
io::handle::prototype::fallback
IO::Handle::Prototype::Fallback(3pm) User Contributed Perl Documentation IO::Handle::Prototype::Fallback(3pm)NAME
IO::Handle::Prototype::Fallback - Create IO::Handle like objects using a set of callbacks.
SYNOPSIS
my $fh = IO::Handle::Prototype::Fallback->new(
getline => sub {
my $fh = shift;
...
},
);
DESCRIPTION
This class provides a way to define a filehandle based on callbacks.
Fallback implementations are provided to the extent possible based on the provided callbacks, for both writing and reading.
SPECIAL CALLBACKS
This class provides two additional methods on top of IO::Handle, designed to let you implement things with a minimal amount of baggage.
The fallback methods are all best implemented using these, though these can be implemented in terms of Perl's standard methods too.
However, to provide the most consistent semantics, it's better to do this:
IO::Handle::Prototype::Fallback->new(
__read => sub {
shift @array;
},
);
Than this:
IO::Handle::Prototype::Fallback->new(
getline => sub {
shift @array;
},
);
Because the fallback implementation of "getline" implements all of the extra crap you'd need to handle to have a fully featured
implementation.
__read
Return a chunk of data of any size (could use $/ or not, it depends on you, unlike "getline" which probably should respect the value of
$/).
This avoids the annoying "substr" stuff you need to do with "read".
__write $string
Write out a string.
This is like a simplified "print", which can disregard $, and "$" as well as multiple argument forms, and does not have the extra
"substr" annoyance of "write" or "syswrite".
WRAPPING
If you provide a single reading related callback ("__read", "getline" or "read") then your callback will be used to implement all of the
other reading primitives using a string buffer.
These implementations handle $/ in all forms ("undef", ref to number and string), all the funny calling conventions for "read", etc.
FALLBACKS
Any callback that can be defined purely in terms of other callbacks in a way will be added. For instance "getc" can be implemented in terms
of "read", "say" can be implemented in terms of "print", "print" can be implemented in terms of "write", "write" can be implemented in
terms of "print", etc.
None of these require special wrapping and will always be added if their dependencies are present.
GLOB OVERLOADING
When overloaded as a glob a tied handle will be returned. This allows you to use the handle in Perl's IO builtins. For instance:
my $line = <$fh>
will not call the "getline" method natively, but the tied interface arranges for that to happen.
perl v5.10.1 2009-09-29 IO::Handle::Prototype::Fallback(3pm)