Hi all,
Does anybody know or guide me on how to remove the first N bytes and the last N bytes from a binary file? Is there any AWK or SED or any command that I can use to achieve this?
Your help is greatly appreciated!!
Best Regards,
Naveen. (1 Reply)
Hello, everyone.
Could someone, please, tell me how to get the number of bytes in the terminal input queue without blocking and without consuming these bytes? I guess it could be called the peek functionality.
I've looked at termio tcgetattr() and tcsetattr() functions but could not find... (4 Replies)
My Script:
#!/bin/sh
date=`date +%y%m%d -d"1 day ago"`
in_dir=/vis/logfiles/to_solmis
cp `grep -il ST~856~ $inbound_dir/*$date*` /vis/sumit/in_ASN/
for i in /vis/sumit/in_ASN/*
do
mkdir -p /vis/sumit/inboundasns.$date
cp `echo $i`... (1 Reply)
Hi,
If I want to copy a 1024 byte data stream in to the target location in 3-bytes chunk, I guess I can use the following script.
dd bs=1024 count=3 if=/src of=/dest
But, I would like to know, how to do it via a C program. I have tried this with memcpy(), that did not help. (3 Replies)
Guys,
I want to get the high CPU utilization from top.
I am using below code :
top -d2 >> /home/dba_monitoring/host_top_output.txt
echo "Script started `date`" > $runlog
usage=`grep "^ *$1" /home/dba_monitoring/host_top_output.txt | awk '{print $12}' | sed 's/%//'`
And getting below... (7 Replies)
Hello guys. I really hope someone will help me with this one..
So, I have to write this script who:
- creates a file home/student/vmdisk of 10 mb
- formats that file to ext3
- mounts that partition to /mnt/partition
- creates a file /mnt/partition/data. In this file, there will... (1 Reply)
Hi Friends,
Could you please tell me why i am getting the below eror while working with awk. I am confused :confused: what to do ?
awk: 0602-591 String 1,9,20,6,6 cannot be longer than 399 bytes. The source line is 1.
The error context is
>>> <<<
awk: 0602-591... (2 Replies)
hello,
suppose, entered input is of 1-40 bytes, i need it to be converted to 40 bytes exactly.
example: if i have entered my name anywhere between 1-40 i want it to be stored with 40 bytes exactly.
enter your name:
donald duck (this is of 11 bytes)
expected is as below - display 11... (3 Replies)
I work at a company that uses a program written in AWK to track various data and prepare reports. Worked with this program for three years plus (the author is no longer with us) and the YTD Production report will not return a report with a date after 123119. This is a problem. Below is the (I... (3 Replies)
Discussion started by: paulgdavitt
3 Replies
LEARN ABOUT DEBIAN
bup-margin
bup-margin(1) General Commands Manual bup-margin(1)NAME
bup-margin - figure out your deduplication safety margin
SYNOPSIS
bup margin [options...]
DESCRIPTION
bup margin iterates through all objects in your bup repository, calculating the largest number of prefix bits shared between any two
entries. This number, n, identifies the longest subset of SHA-1 you could use and still encounter a collision between your object ids.
For example, one system that was tested had a collection of 11 million objects (70 GB), and bup margin returned 45. That means a 46-bit
hash would be sufficient to avoid all collisions among that set of objects; each object in that repository could be uniquely identified by
its first 46 bits.
The number of bits needed seems to increase by about 1 or 2 for every doubling of the number of objects. Since SHA-1 hashes have 160 bits,
that leaves 115 bits of margin. Of course, because SHA-1 hashes are essentially random, it's theoretically possible to use many more bits
with far fewer objects.
If you're paranoid about the possibility of SHA-1 collisions, you can monitor your repository by running bup margin occasionally to see if
you're getting dangerously close to 160 bits.
OPTIONS --predict
Guess the offset into each index file where a particular object will appear, and report the maximum deviation of the correct answer
from the guess. This is potentially useful for tuning an interpolation search algorithm.
--ignore-midx
don't use .midx files, use only .idx files. This is only really useful when used with --predict.
EXAMPLE
$ bup margin
Reading indexes: 100.00% (1612581/1612581), done.
40
40 matching prefix bits
1.94 bits per doubling
120 bits (61.86 doublings) remaining
4.19338e+18 times larger is possible
Everyone on earth could have 625878182 data sets
like yours, all in one repository, and we would
expect 1 object collision.
$ bup margin --predict
PackIdxList: using 1 index.
Reading indexes: 100.00% (1612581/1612581), done.
915 of 1612581 (0.057%)
SEE ALSO bup-midx(1), bup-save(1)BUP
Part of the bup(1) suite.
AUTHORS
Avery Pennarun <apenwarr@gmail.com>.
Bup unknown-bup-margin(1)