hello all
just trying to write a script that will read a file (line by line) and substitute (tht line) in a different file if (tht line) is present in second file
Ex: script has to read file A (line by line) and if file B has tht line it should get substituted with the line in file A
... (3 Replies)
Hi,
I have two files. Want to make an addition of the fifth column of from both the files and redirect it to a third file.
Both files have same records except fifth field and same record should be inserted into new file having fifth field as addition of fifth fields of both files.
for... (2 Replies)
Hi,
I have to read a file and translate the contents including substituting the variables if any and write to another file without using sed or awk.
For ex:-
inputfile.txt
-----------
servername=$SERVER
application=$APPL
outputfile.txt
------------
servername=actual server name... (2 Replies)
Hi, I am creating a ksh script to search for a string of text inside files within a directory tree. Some of these file are going to be read/execute only. I know to use chmod to change the permissions of the file, but I want to preserve the original permissions after writing to the file. How can I... (3 Replies)
MyFile contains:
ALTER TABLE $DBN.$TBN
ADD $COL $TYP COMPRESS ($VAL);
I need to cat the file and have it substitute all of the variables with their contents. cat MyFile does not work. The following works for the first line, but errors on the second line because of the paren:
$ while read... (2 Replies)
I want change the file when the line contains $(AA) but NOT contains $(BB), then change $(AA) to $(AA) $(BB)
eg:
$(AA) something
$(AA) $(BB) something (7 Replies)
Hi,
I have file1 like this:
a 64
b 66
c 67and file2 like this:
@1234
1123
aabbcc
@5453
5543
ccbaI want to replace each letter of the third line in file2 with corresponding number in file1. So desired output is,
@1234
1123
646466666767
@5453
5543
67676664I tried something like... (4 Replies)
I have a huge script which is defining variables with full path of commands in the beginning of code and using those variables in the script.
For Example:
ECHO=/bin/echo
LS=/bin/ls
SED=/bin/sed
AWK=/bin/awk
UNAME=/bin/uname
PS=/bin/ps
DATE=/bin/date
GREP=/bin/grep
$ECHO "hello... (1 Reply)
Hi,
I have a script in which the file name is always known, but the extension could vary. I want to be able to use a single variable; no if-else statements. For example, if I have config.txt in the directory then that's what I want to use, but if config.xml is in the directory then use that. The... (9 Replies)
Discussion started by: ocbit
9 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)