If you want to add a default/dummy within a bash script, you could do this:-
This says "assign the value of $my_var to itself, or the string default if it is empty or not set." You can have another variable instead of the string default if you want to.
If no arguments are entered I wanna be able to read 2 arguments, i have done like this but it doesnt work:
x=0
until #loop starts
do
if ; then
echo No arguments were entered, please enter 2 arguments.
read $1 $2
elif || ; then
echo $#... (0 Replies)
Hi,
I'm trying to write a script that reads filenames from a file and use these filenames in a loop. The filenames are all on one line and the problem is that these filenames have wildcards like * and braces like in them.
Right now what I'm doing is something like this:
echo "reading from... (0 Replies)
Hi.
I have the script shown below. If I execute it form the command line it seems to work properly, but when I fun it using the unix "at" command
"at -m now < ./kill-at-job.sh"
It appears to hang. Below is the script, the input file, and the execution as reported in the e-mail from the "at"... (3 Replies)
i get a name from user first name : last name, in this format. Now i am saving this to a file. what i want is, I do not want to save any name if I already have one entry o that same name..what should i do
for example
user give robert fernandez
this will save in file as robert:fernandez.
if... (5 Replies)
Hi All,
I am trying to read a .csv file which has some 6 columns.
Eg: samp.csv
one, two, three, four
six, seven, eight, nine
I used the following code,
for line in `cat samp.csv`
do
echo "$line"
done
It displays every comma seperated values in each line like,
one,... (1 Reply)
I have a file that has four values on each line and I'd like to give each column a variable name and then use those values in each step of a loop. In bash, I believe you could use a while loop to do this or possibly a cat command, but I am super new to programming and I'm having trouble decoding... (2 Replies)
I have the following code and I am calling it using
./raytrac.bash -u
and getting problems. For some reason opt_usage is still 0.
opt_usage=0
iarg=0
narg=$#
while (($iarg < $narg))
do
(( iarg = $iarg + 1 ))
arg=$argv
usrInputFlag=`echo $arg | awk '/=/ {print 1}; ! /=/... (22 Replies)
I've a file in linux with following text:
;ip address hostname put-location alt-put-location tftpserver
192.168.1.1 r01-lab1-net /mnt/nas1/fgbu/ /opt/fgbu/devicebackup 192.168.1.254Now I want to read these values and assign them to particular variables... (6 Replies)
Hi all,
Given here under a section of a script I am using.
SIMDIR="/home/Ins/forces"
cd $SIMDIR
for file in `ls *.forces`
do
basename=`echo $file | sed 's/\.*$//'`
extname=`echo $file | sed 's/*\(*\)\.\(.*\)/\2\1/'`
echo "Processing file: "$basename
python convert.py... (4 Replies)
Cope sample1: test.sh
i=0
echo " Outside loop i = $i "
while
do
i=$(( $i + 1))
echo "Inside loop i = $i "
done
echo " Out of loop i is : $i "
When run output :
Outside loop i = 0
Inside loop i = 1
Inside loop i = 2
Inside loop i = 3
Inside loop i = 4
Inside loop i = 5
Inside... (8 Replies)
Discussion started by: Adarshreddy01
8 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)