I have a problem that I want to insert and delete some chars in the middle of a file. fopen() and fdopen() just allow to append at the end.
Is there any simple method or existing library that allow these actions? Thanks in advance.:confused: (7 Replies)
I am trying to strip out certain characters from a string on both (left & right) sides. For example, line=see@hear|touch, i only want to echo the "hear" part. Well i have tried this approach:
line=see@hear|touch
templine=${line#*@} #removed "see@"
echo ${templine%%\|*} #removed... (4 Replies)
Hi All,
I have a file which is delimeted with the character '. i need to replace this character with the same character and also a new line.
Can anyone please help me with the tr command for this.
Many thanks
Karan (11 Replies)
Hello,
I have a file with many lines with below format:
\abc\\1234
jkl\\567
def\\345
\pqr\\567
\xyz\\234
Here, i need to do 2 things.
1. replace \\ with \
2. remove starting \
so output to be as below: (11 Replies)
Hi fellow experts,
I have a question for you. Data looks like:
00877,05/13/2010,PBO,P,0000708331,518
00877,05/13/2010,PBO,P,0000708331,519
...
...
00877,05/13/2010,PBO,P,0000708331,2103
00877,05/13/2010,PBO,P,0000708331,2104,etc,etc
Basically I have to replace 518,519,2103,2104,... (4 Replies)
sed -e "s// /g" old.txt > new.txt
While I do know some control characters need to be escaped, can normal characters also be escaped and still work the same way? Basically I do not know all control characters that have a special meaning, for example, ?, ., % have a meaning and have to be escaped... (11 Replies)
Hi,
I have a text file which is output from a server and it lists all the files in a specific volume. However, the volume name appears as volume_name:.
I would like to replace this with \\volume_name\volume_name. This is not a problem in itself as I can use sed to globally look for the... (8 Replies)
Hi,
I need to correct href portion of the lines to edit out spaces from the line starting with position "<a href=" and ending at "target="
Below are 2 examples of extra space added by the server:
<td width=251 colspan=9 rowspan=22> <font size=2 face="courier"><tt><style>{font:7pt Courier ... (4 Replies)
Discussion started by: friedmi
4 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)