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Full Discussion: Redirect overwrites itself
Top Forums Shell Programming and Scripting Redirect overwrites itself Post 302423691 by alister on Friday 21st of May 2010 05:39:44 PM
Old 05-21-2010
Quote:
Originally Posted by rlopes
I bet many people faced this problem before:

The command below will result in a blank file:

Code:
$ cat myfile | grep pattern > myfile

Is there any easy way to do it?
Not sure if this qualifies as "easy", but if you're the adventurous type:
Code:
(rm myfile; grep -v pattern > myfile) < myfile

I elaborate on how this works and the risks involved at the end of the post at https://www.unix.com/302407978-post5.html

Regards,
Alister
 

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LEARN ABOUT OPENSOLARIS

rsvg

rsvg(1) 							   User Commands							   rsvg(1)

NAME

       rsvg - convert SVG files into raster images

SYNOPSIS

       rsvg  [--dpi-x=number]  [--dpi-y=number] [--format png|jpeg] [--height=integer] [--quality=integer] [--version] [--width integer] [--x-zoom
       number] [--y-zoom number] infile.svg outfile.png | outfile.jpeg

DESCRIPTION

       rsvg converts SVG images into PNG and JPEG raster images.

OPTIONS

       The following options are supported:

       -d --dpi-x=number       Set the X resolution of the image in pixels per inch. The default value is 90dpi.

       -p --dpi-y=number       Set the Y resolution of the image in pixels per inch. The default value is 90dpi.

       -f, --format png|jpeg   Specify the output format for the converted image. The default value is png.

       -h, --height=integer    Specify the height of the converted image. The default value is the height of the original image.

       -h, --quality=integer   JPEG quality value

       -v --version	       Display rsvg version information.

       -w, --width integer     Specify the width of the converted image. The default value is the width of the original image.

       -x, --x-zoom number     X Zoom factor, as a percentage. The default value is 1.0.

       -y, --y-zoom number     Y Zoom factor, as a percentage. The default value is 1.0.

OPERANDS

       The following operands are supported:

       infile.svg	       The name of the input SVG file.

       outfile.png	       The name of the converted PNG file.

       outfile.jpeg	       The name of the converted JPEG file.

EXAMPLES

       Example 1: Converting an SVG Image to PNG

       example% rsvg myfile.svg myfile.png

       Example 2: Converting an SVG Image to JPEG at 300dpi Resolution

       example% rsvg -f jpeg -d 300 myfile.svg myfile.jpg

EXIT STATUS

       The following exit values are returned:

       0	Application exited successfully

       >0	Application exited with failure

FILES

       The following files are used by this application:

       /usr/bin/rsvg	       Executable to convert SVG files into raster images

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWlibrsvg		   |
       +-----------------------------+-----------------------------+
       |Interface stability	     |Volatile			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       http://librsvg.sourceforge.net/

       http://www.w3.org/TR/SVG11/

       librsvg-2(3), attributes(5)

NOTES

       Original man page written by Dom Lachowicz (cinamod@hotmail.com), Alex Larsson (alex@redhat.com), and others.

       Updated by Laszlo Peter, Sun Microsystems Inc., 2004.

SunOS 5.11							    7 Sep 2004								   rsvg(1)
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