In addition to what sea said (and to what i wholeheartedly agree):
1) do not use "open-ended" for-loops, because they can have side-effects. Something like (you are effectively doing the same)
will work with several or several hundreds of files but might break with a "too many arguments"-error or a "input line too long"-error with several thousands of files. Do a
instead. This will work with even the biggest amount of files.
2) Never, NEVER use backticks any more. They are outdated and only there for backwards compatibility with other outdated software. Use the POSIX-compliant
instead.
Btw.: i am not sure what you are trying to do but to me this seems to be a search for symbolic links. This can more easily be done by:
hello
i have a requirement where i have a direcotry in which i get files in the format
STOCKS.20080114.dat
STOCKS.20080115.dat
STOCKS.20080117.dat
STOCKS.20080118.dat
i need to loop through the directory and sort by create date descending order and i need to process the first file.
... (1 Reply)
I've written a script to check for Oracle's listener, eventman and pmon processes however there are several databases that startup which can take several minutes.
I'd like to add code to my current script that greps for the process “startup” and whether its condition is true or false. If the... (1 Reply)
Hi Gurus,
Could you please help me to create a shell script that will be started by a cron job once every night at 24.00 h (that should bee easy:))
The shell script should control every 30 seconds the name of a process, and when the process doesn't run anymore it should execute a few further... (12 Replies)
for two txt files, f1 and f2, I like to do the following
grep "abcde" f1 > abcde$f1
grep "xyz" f1 > xyz$f1
can I use a loop to get this done? Thanks
for i in f1 f2
do
grep "abcde" $i > abcde$i
grep "xyz" $i > xyz$i
...
done (11 Replies)
Hi,
I want to create a script who will check if the java process is running & if it finds the process is still there it continues to execute & when the process completes it exit from the script.
I have written a code to check & notify the process existence but i am not getting how to write... (4 Replies)
Hello forum members,
I hope you can help me with this I don't know hot to reach.
I have a list of files in "/home/MyPath1/" and in "/home/MyPath2/". The files have the same name in both folders.
(but different content, the content doesn't matter here I think)
/home/MyPath1/
filename1.txt... (4 Replies)
I have the following code running against a file. The file can have upwards of 10000 lines.
problem is, the for loop takes a while to go through all those lines. is there a faster way to go about it?
for line in `grep -P "${MONTH} ${DAY}," file | ${AWK} -F" " '{print $4}' | awk -F":"... (2 Replies)
Hi all,
Looking for some help, I have written a very simple script to pass to PowerHA to act as an indicator to activate failover required.
Where i get completely lost is I have to create a wait and carry out the grep for the process once every 10 seconds this works but need to embed this... (1 Reply)
Hi,
I have a file with contents
So what I have to do is
In short, break the file after every 6 lines and then truncate new line to tab for these 6 lines.
I am not able to execute the for loop in awk properly.
The idea is something like this:
less file| awk '{for .... {if ((nr>=1)... (7 Replies)
As I would like to test the open files usage , I would like to have a process that use the open files up to a certain amount eg. 1000 .
If I want to have a script ( may be run in a loop ) that could repeatly use open files resource , so that the usage of open files increases , may I know how to... (10 Replies)
Discussion started by: ust
10 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)