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Full Discussion: Get file's first x bytes
Top Forums Shell Programming and Scripting Get file's first x bytes Post 302805763 by Don Cragun on Friday 10th of May 2013 09:55:15 PM
Old 05-10-2013
If you don't know what you want, I have no idea whether what I suggest will succeed. I am guessing that the intent of the pipeline:
Code:
head -c 10000k /var/dump.log | head -c 6000k

is to extract the first 10000*1000 bytes from /var/dump.log and then extract the first 6000*1000 bytes from that. That is equivalent to extracting the first 6000*1000 bytes from /var/dump.log. If you had specified 10000kB and 6000kB, that is what would be done according to the Linux head man page. If you had used 10000K and 6000K, the multiplier would be 1024 instead of 1000 according to the Linux head man page. If the count had been negative in the 2nd call to head, the command line would make more sense since it would then be getting the last 6000*(1000 or 1024) bytes from the first 10000*(1000 or 1024) bytes. But, I can only work with the command line you supplied and guess at the multiplier (or block size) you want. So:
Code:
dd if=/var/dump.log count=6000 bs=1000

might do what you want. If you want a block size of 1024 instead of 1000, change the bs=1000 to bs=1024.

If wanted the last 6000 blocks of the first 10000 blocks from the file, you could try:
Code:
dd if=/var/dump.log skip=4000 count=6000 bs=1000

This User Gave Thanks to Don Cragun For This Post:
 

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Graphics::Primitive::Insets(3pm)			User Contributed Perl Documentation			  Graphics::Primitive::Insets(3pm)

NAME
Graphics::Primitive::Insets - Space between things DESCRIPTION
Graphics::Primitive::Insets represents the amount of space that surrounds something. This object can be used to represent either padding or margins (in the CSS sense, one being inside the bounding box, the other being outside) SYNOPSIS
use Graphics::Primitive::Insets; my $insets = Graphics::Primitive::Insets->new({ top => 5, bottom => 5, left => 5, right => 5 }); METHODS
Constructor new Creates a new Graphics::Primitive::Insets. Instance Methods as_array Return these insets as an array in the form of top, right, bottom and left. bottom Set/Get the inset from the bottom. equal_to Determine if these Insets are equal to another. left Set/Get the inset from the left. right Set/Get the inset from the right. top Set/Get the inset from the top. zero Sets all the insets (top, left, bottom, right) to 0. AUTHOR
Cory Watson, "<gphat@cpan.org>" SEE ALSO
perl(1) COPYRIGHT &; LICENSE Copyright 2008-2010 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 2010-08-21 Graphics::Primitive::Insets(3pm)
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