Sponsored Content
Full Discussion: Empty out the file
Top Forums Shell Programming and Scripting Empty out the file Post 302532721 by alister on Wednesday 22nd of June 2011 12:24:38 AM
Old 06-22-2011
Quote:
Originally Posted by itkamaraj
the below command also null out the file
Code:
 
echo "" > file_name

Actually, it won't. It'll write one byte (a newline character).

Regards,
Alister
 

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

empty file in hp-ux

Hi, I need your help. How can I create an empty filename with a specific size, in hp-ux? Regards, Mizi (2 Replies)
Discussion started by: Mizi
2 Replies

2. Shell Programming and Scripting

How to empty a file(already created)

What is the command to empty an already existing file. please provide me.i used Touch cmd to empty the file.but it changing the time only. (4 Replies)
Discussion started by: laknar
4 Replies

3. Shell Programming and Scripting

File is not empty?

How do I check to make sure a file is not zero bytes? Something like: if then ????? (7 Replies)
Discussion started by: lesstjm
7 Replies

4. UNIX for Dummies Questions & Answers

how to find empty folders without using -empty

hi all: my solaris FIND does not support find myFolder -type d -empty how can i find the empty folders? thanks! (7 Replies)
Discussion started by: lasse
7 Replies

5. UNIX for Dummies Questions & Answers

Trying to empty file using > but the file size increasing when next append

AIX 5.3 / KSH I have a Java application which creates a log file a.log. I have a KSH script which does the following action cp a.log /directory2/b.log > a.log After this the file size goes to 0 as per "ls -l" Then next time when the application writes into this file, the file size... (4 Replies)
Discussion started by: firdousamir
4 Replies

6. Shell Programming and Scripting

how to see if the file is empty or not?

hi how can I determine, if a file is empty or not?I am using read line clause. The script should be like: while read line do if(file is empty) then; ...... done < $blacklist (1 Reply)
Discussion started by: tjay83
1 Replies

7. UNIX for Dummies Questions & Answers

Getting same exit status for empty and non empty file

Hi All, I am checking for a empty input file to do some further action , but I am getting exit status 0 in both the cases , for empty and non empty file both. The value of $? is coming 0 in if part also and else part too. #!/bin/ksh if ]; then echo "data" # exit 0 echo "$?" else... (4 Replies)
Discussion started by: mavesum
4 Replies

8. Shell Programming and Scripting

while file is empty

how can i use while loop ? while file is empty do.... if not empty do ..... in bash (1 Reply)
Discussion started by: Trump
1 Replies

9. Shell Programming and Scripting

if/else with an empty file...

Hi there, I'm just starting out with shell scripting and I'm trying to make a test where the script will basically run yum check-update to find out if the server has any available and if it does it e-mails me but if not it will just stop there. I have it working if there are actually... (7 Replies)
Discussion started by: Imnewtothis
7 Replies

10. Shell Programming and Scripting

awk to reformat output if input file is empty, but not if file has data in it

The below awk improved bu @MadeInGermany, works great as long as the input file has data in it in the below format: input chrX 25031028 25031925 chrX:25031028-25031925 ARX 631 18 chrX 25031028 25031925 chrX:25031028-25031925 ARX 632 14... (3 Replies)
Discussion started by: cmccabe
3 Replies
Graphics::Primitive::Component(3pm)			User Contributed Perl Documentation		       Graphics::Primitive::Component(3pm)

NAME
Graphics::Primitive::Component - Base graphical unit DESCRIPTION
A Component is an entity with a graphical representation. SYNOPSIS
my $c = Graphics::Primitive::Component->new({ origin => Geometry::Primitive::Point->new({ x => $x, y => $y }), width => 500, height => 350 }); LIFECYCLE
prepare Most components do the majority of their setup in the prepare. The goal of prepare is to establish it's minimum height and width so that it can be properly positioned by a layout manager. $driver->prepare($comp); layout This is not a method of Component, but a phase introduced by the use of Layout::Manager. If the component is a container then each of it's child components (even the containers) will be positioned according to the minimum height and width determined during prepare. Different layout manager implementations have different rules, so consult the documentation for each for details. After this phase has completed the origin, height and width should be set for all components. $lm->do_layout($comp); finalize This final phase provides and opportunity for the component to do any final changes to it's internals before being passed to a driver for drawing. An example might be a component that draws a fleuron at it's extremities. Since the final height and width isn't known until this phase, it was impossible for it to position these internal components until now. It may even defer creation of this components until now. It is not ok to defer all action to the finalize phase. If you do not establish a minimum hieght and width during prepare then the layout manager may not provide you with enough space to draw. $driver->finalize($comp); draw Handled by Graphics::Primitive::Driver. $driver->draw($comp); METHODS
Constructor new Creates a new Component. Instance Methods background_color Set this component's background color. border Set this component's border, which should be an instance of Border. callback Optional callback that is fired at the beginning of the "finalize" phase. This allows you to add some sort of custom code that can modify the component just before it is rendered. The only argument is the component itself. Note that changing the position or the dimensions of the component will not re-layout the scene. You may have weird results of you manipulate the component's dimensions here. class Set/Get this component's class, which is an abitrary string. Graphics::Primitive has no internal use for this attribute but provides it for outside use. color Set this component's foreground color. fire_callback Method to execute this component's "callback". get_tree Get a tree for this component. Since components are -- by definiton -- leaf nodes, this tree will only have the one member at it's root. has_callback Predicate that tells if this component has a "callback". height Set this component's height. inside_bounding_box Returns a Rectangle that defines the edges of the 'inside' box for this component. This box is relative to the origin of the component. inside_height Get the height available in this container after taking away space for padding, margin and borders. inside_width Get the width available in this container after taking away space for padding, margin and borders. margins Set this component's margins, which should be an instance of Insets. Margins are the space outside the component's bounding box, as in CSS. The margins should be outside the border. maximum_height Set/Get this component's maximum height. Used to inform a layout manager. maximum_width Set/Get this component's maximum width. Used to inform a layout manager. minimum_height Set/Get this component's minimum height. Used to inform a layout manager. minimum_inside_height Get the minimum height available in this container after taking away space for padding, margin and borders. minimum_inside_width Get the minimum width available in this container after taking away space for padding, margin and borders. minimum_width Set/Get this component's minimum width. Used to inform a layout manager. name Set this component's name. This is not required, but may inform consumers of a component. Pay attention to that library's documentation. origin Set/Get the origin point for this component. outside_height Get the height consumed by padding, margin and borders. outside_width Get the width consumed by padding, margin and borders. finalize Method provided to give component one last opportunity to put it's contents into the provided space. Called after prepare. padding Set this component's padding, which should be an instance of Insets. Padding is the space inside the component's bounding box, as in CSS. This padding should be between the border and the component's content. page If true then this component represents stand-alone page. This informs the driver that this component (and any children) are to be renderered on a single surface. This only really makes sense in formats that have pages such as PDF of PostScript. prepare Method to prepare this component for drawing. This is an empty sub and is meant to be overridden by a specific implementation. preferred_height Set/Get this component's preferred height. Used to inform a layout manager. preferred_width Set/Get this component's preferred width. Used to inform a layout manager. to_string Get a string representation of this component in the form of: $name $x,$y ($widthx$height) visible Set/Get this component's visible flag. width Set/Get this component's width. AUTHOR
Cory Watson, "<gphat@cpan.org>" BUGS
Please report any bugs or feature requests to "bug-geometry-primitive at rt.cpan.org", or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Geometry-Primitive <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Geometry-Primitive>. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes. COPYRIGHT &; LICENSE Copyright 2008-2009 by Cory G Watson. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. perl v5.12.3 2011-06-02 Graphics::Primitive::Component(3pm)
All times are GMT -4. The time now is 05:04 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy