hello people,
i am trying to accomplish what i thought should be a simple task: find a token in a file and delete a number (let's say 25) of lines following the token.
in sed, i can't figure out how to do a relative address (i.e. something like /token/25dd to delete 25 lines) and in gnu grep,... (3 Replies)
hello all
I have bunch of files containing lines of text that surrounding by <# .......#> tags
I like to delete this lines from the text files whiteout open the files , can it be done with sed ?
or other unix tool (perl mybe )? (2 Replies)
I have a file which contains blocks of text - each block is a multi-lines text delimited by blank lines eg.
<blank line>
several lines of text
...
pattern found on this line
several more lines of text
...
<blank line>
How do you delete the block of text (including the blank lines) when... (17 Replies)
Hi,
I would like to print a block of text between 2 regular expression using Sed,
This can be achieved by using the command as shown below, however my problem is the same block of text is repeated twice. I would like to eliminate the duplicate block of text.
For Example
If my file... (5 Replies)
Hello. I'm trying to delete the lines of a file does not contain the letter "T " (for example) at position 26.
So far, I could only print the result:
awk '{if (substr ($ 1,1,26)! ~ / T /) print}' file.txt
How I can do to eliminate the lines that meet this condition?
Help please. ... (4 Replies)
Hi All,
I have a text file which looks like this:
computer programming
systems engineering
I want to get rid of these square brackets and also the text that is inside these brackets. So that my final text file looks like this:
computer programming
systems engineering
I am using... (3 Replies)
Hi everyone, this is my first post here, I hope someone can help me.
I have a file which I need to delete characters '_F3' from the end of the text in the first column. The problem is that the characters may also occur elsewhere in the file (i.e. second columns onwards). I tried sed (thinking I... (6 Replies)
My apologies if this has been answered in a previous post. I've been doing a lot of searching, but I haven't been able to find what I was looking for. Specifically, I am wondering if I can utilize sed and/or awk to locate two strings in a file, and replace everything between those two strings... (12 Replies)
Hi,
I have a requirement in which i need to replace text as below -
<stringProp name="Recipe"><AddGroup Name="1001" Path="ServiceAdministration/Controls/1001/ServiceSwitches">
<Param Name="AttributeName" Value="HeaderManipRspIngressRuleSet" Type="String" />
<Param Name="Value"... (0 Replies)
Hi,
1/
i have file test.txt
1 Jul 28 08:35:29 2014-07-28 Root::UserA
1 Jul 28 08:36:44 2014-07-28 Root::UserB i want to delete the seconds of the file, and the Root:: and the output will be:
1 Jul 28 08:35 2014-07-28 UserA
1 Jul 28 08:36 2014-07-28 UserB 2/i have another file test2.txt:... (8 Replies)
Discussion started by: fxsme
8 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)