10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hi All,
I have a 17GB file and i want to set the first column from 1234567890 to just 0, how can i do it using sed command?
thanks,
---------- Post updated at 03:09 PM ---------- Previous update was at 03:07 PM ----------
btw, my file is delimited by "|" and 1234567890 is just an... (7 Replies)
Discussion started by: fedora132010
7 Replies
2. Shell Programming and Scripting
I am looking at the NR==FNR posts and trying to use them to achieve the following but I am not getting it.
I have 2 files. I want to match column 8 in file 1 with column 2 in file 2. When they match I want to replace column 9 in file 1 with column 1 in file 2.
This is and extract from file 1
... (5 Replies)
Discussion started by: kieranfoley
5 Replies
3. Shell Programming and Scripting
I have one file as it has the following format
File1
S No Site IP Address
1 Australia 192.168.0.1/26
2 Australia 192.168.0.2/26
3 Australia 192.168.0.3/26
I need awk/sed command to replace the column2 value ( under Site) with some other... (8 Replies)
Discussion started by: samaritan
8 Replies
4. UNIX for Advanced & Expert Users
Hi All,
I have a fixedwidth file of length 3000. Now i want to copy a column of 4 chars i.e( length 1678-1681) to column 1127 – 1171 to the same file.
Please let me know how can i achive using a single command in fixed width file.
Also source column length is 4 chars and target column length... (4 Replies)
Discussion started by: kiranparsha
4 Replies
5. Shell Programming and Scripting
Can anyone please help with this? I have 2 files as given below.
If 2nd column of file1 has pattern foo1@a, find the matching 1st column in file2 & replace 2nd column of file1 with file2's value.
file1
abc_1 foo1@a ....
abc_1 soo2@a ...
def_2 soo2@a ....
def_2 foo1@a ........ (7 Replies)
Discussion started by: prashali
7 Replies
6. UNIX for Dummies Questions & Answers
Dear all,
I have a file1.pdb in pdb format and a dat file2 containing values, corresponding to the atoms in the pdb file. these values (file2.dat) need to be in the column instead of the 0.00 (file1) values for each atom in file1.pdb .(the red values must be replaced by the blue ones,in order)... (11 Replies)
Discussion started by: chen.xiao.po
11 Replies
7. Shell Programming and Scripting
Hello,
I am trying to replace the column in file1 with the column from file2. The two files will have the same amount of rows. Each row will correspond with the same row in the other file.
File1
"Replace this column"
500 13-APR-2011... (11 Replies)
Discussion started by: doobe01
11 Replies
8. UNIX for Dummies Questions & Answers
Hello,
I have a file with four columns and I would like to replace values in the second column only.
An arbitrary example is:
100 A 105 B
200 B 205 C
300 C 305 D
400 D 405 E
500 E 505 F
I need to replace the second column as shown below:
... (4 Replies)
Discussion started by: Gussifinknottle
4 Replies
9. Shell Programming and Scripting
Match column 3 in file1 to column 1 in file 2 and replace with column 2 from file2
file 1 sample
SNDK 80004C101 AT
XLNX 983919101 BB
NETL 64118B100 BS
AMD 007903107 CC
KLAC 482480100 DC
TER 880770102 KATS
ATHR 04743P108 KATS... (7 Replies)
Discussion started by: rydz00
7 Replies
10. UNIX and Linux Applications
Hi All,
I need to replace the last 19 bytes of the following string
My_Org_Testing_20090102_231124.txt (Text_Date_Time.txt).
I would like to derive the current time using "date +%Y%m%d_%H%M%S.txt" and replace the last 19 bytes of the above string
I would appreciate if someone could... (3 Replies)
Discussion started by: rpk2008
3 Replies
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)