Hello,
I need to insert a line (like a header) as the first line of a very huge file (about 3 ml rows). I am able to do it with sed, but redirecting the output and creating a new file takes quite some time. I was wondering if there was a more efficient way of doing it?
Any help would be... (3 Replies)
Hello all
im doing simple parsing on text file , but now I need to insert
string before the first line of the text file , how can I do that in perl? (3 Replies)
Hi,
My File 'temp.txt' contents are like this.
<Managers>
Mng={{FIL|FAVEI.mng|111}|15.000000|17.000000|17.000000|
Mng={{FIL|FAPSV.mng|222}|3.000000|0.000000|0.000000|0.000000|
Mng={{FIL|FAVIF.mng|333}|8.000000|8.000000|8.000000|8.000000|... (3 Replies)
hello mighty all
there is a line of 50 words and i need to take a random number of words from the beginning (20 words for example) then put my word then add other 10 words from the continue then add another my special word then add 20 words till the end..
my own knowledge base can say it is... (12 Replies)
how to insert a line of text that is next to the current line(file pointer pointing to) in the file ?? :wall:
ex:
suppose a file named 'Sample' has the following content in it.
this is to
give clear idea about
the problem
if file pointer is pointing to the first line then i want to... (3 Replies)
HI,
I have a text file in which I have removed all new lines as I would like to introduce a new line at the end of each record in the file. There is no common end line for all the records. A new record will start by *RECORD*. So I want to introduce a new line before this line *RECORD*. So Can... (2 Replies)
Hi,
I need to insert a new line containing the string "QUERY" above every 5 lines.
The below piece of code inserts a new line after every 5th line
awk '{print $0} !(NR%5) {print "QUERY"}'
sed 'n;n;n;n;G;' --> I do not know how to give "QUERY" string here
But I need to insert it before... (4 Replies)
I have a test file that I want to read and insert only certain lines into the
the table based on a filter.
1. Rread the log file 12 Hours back Getdate() -12 Hours
2. Extract the following information on for lines that say "DUMP is
complete"
A. Date
B. Database Name
C.... (2 Replies)
Hi All,
I am using UNix Sun OS sun4u sparc SUNW,SPARC-Enterprise
My intention is to insert a line of text after 13th line of every file inside a particular directory.
While trying to do it for a single file , i am using sed
sed '3 i this is the 4th line' filename
sed: command garbled: 3... (5 Replies)
Discussion started by: gotamp
5 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)