I have a file which has about 500K records and I need to delete about 50 records from the file. I know line numbers and am using
sed '13456,13457,......d' filename > new file.
It does not seem to be working.
Any help will greatly appreciated. (5 Replies)
Input:
a
b
b
c
d
d
I need:
a
c
I know how to get this (the lines that have duplicates) :
b
d
sort file | uniq -d
But i need opossite of this. I have searched the forum and other places as well, but have found solution for everything except this variant of the problem. (3 Replies)
Hi All,
I have a very huge file (4GB) which has duplicate lines. I want to delete duplicate lines leaving unique lines. Sort, uniq, awk '!x++' are not working as its running out of buffer space.
I dont know if this works : I want to read each line of the File in a For Loop, and want to... (16 Replies)
Hi
This is a sample of my data file.
##field PH01000000 1 4869017
#PH01000000G0240
WWW278545G0240 P.he_model_v1.0 erine 119238 121805 . - . ID=PH01000000G0240;Description="zinc finger, C3HC4 type domain containing protein, expressed"... (7 Replies)
Hello,
I have file of more than 10000 lines.
I want to delete 40 lines after every 20 lines.
e.g from a huge file, i want to delete line no from 34 - 74, then 94 - 134 etc and so on.
Please let me know how i can do it.
Best regards, (11 Replies)
Hi,
I have a txt document having a format like this:
DATA1 | DATA2 | DATA3 | 23-JAN-20 23:41:34
DATA1 | DATA2 | DATA3 | 23-JAN-20 23:41:32
DATA1 | DATA2 | DATA3 | 23-JAN-20 23:41:30
...
DATA1 | DATA2 | DATA3 | 23-JAN-20 22:35:31
DATA1 | DATA2 | DATA3 | 23-JAN-20 22:30:34
DATA1 | DATA2 |... (1 Reply)
Discussion started by: gc_sw
1 Replies
LEARN ABOUT DEBIAN
file::mimeinfo::cookbook
File::MimeInfo::Cookbook(3pm) User Contributed Perl Documentation File::MimeInfo::Cookbook(3pm)NAME
File::MimeInfo::Cookbook - various code snippets
DESCRIPTION
Some code snippets for non-basic uses of the File::MimeInfo module:
Matching an extension
A file does not have to actually exist in order to get a mimetype for it. This means that the following will work:
my $extension = '*.txt';
my $mimetype = mimetype( $extension );
Mimetyping an scalar
If you want to find the mimetype of a scalar value you need magic mimetyping; after all a scalar doesn't have a filename or inode.
What you need to do is to use IO::Scalar :
use File::MimeInfo::Magic;
use IO::Scalar;
my $io_scalar = new IO::Scalar $data;
my $mimetype = mimetype( $io_scalar );
In fact most other "IO::" will work as long as they support the "seek()" and "read()" methods. Of course if you want really obscure
things to happen you can always write your own IO object and feed it in there.
Be aware that when using a filehandle like this you need to set the ":utf8" binmode yourself if apropriate.
Mimetyping a filehandle
Regrettably for non-seekable filehandles like STDIN simply using an "IO::" object will not work. You will need to buffer enough of the
data for a proper mimetyping. For example you could mimetype data from STDIN like this:
use File::MimeInfo::Magic;
use IO::Scalar;
my $data;
read(STDIN, $data, $File::MimeInfo::Magic::max_buffer);
my $io_scalar = new IO::Scalar $data;
my $mimetype = mimetype( $io_scalar );
Be aware that when using a filehandle like this you need to set the ":utf8" binmode yourself if apropriate.
Creating a new filename
Say you have a temporary file that you want to save with a more proper filename.
use File::MimeInfo::Magic qw#mimetype extensions#;
use File::Copy;
my $tmpfile = '/tmp/foo';
my $mimetype = mimetype($tmpfile);
my $extension = extensions($mimetype);
my $newfile = 'untitled1';
$newfile .= '.'.$extension if length $extension;
move($tmpfile, $newfile);
Force the use of a certain database directory
Normally you just need to add the dir where your mime database lives to either the XDG_DATA_HOME or XDG_DATA_DIRS environment variables
for it to be found. But in some rare cases you may want to by-pass this system all together. Try one of the following:
@File::MimeInfo::DIRS = ('/home/me/share/mime');
eval 'use File::MimeInfo';
die if $@;
or:
use File::MimeInfo;
@File::MimeInfo::DIRS = ('/home/me/share/mime');
File::MimeInfo->rehash();
This can also be used for switching between databases at run time while leaving other XDG configuration stuff alone.
AUTHOR
Jaap Karssenberg <pardus@cpan.org>
Copyright (c) 2005, 2012 Jaap G Karssenberg. All rights reserved. This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
SEE ALSO
File::MimeInfo
perl v5.14.2 2012-01-05 File::MimeInfo::Cookbook(3pm)