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1. UNIX for Beginners Questions & Answers
Greetings all,
I am looking for a version of Linux that I can practice my scripting skills on. Currently, I support a massive system running on AIX. I want to do more with awk, sed, grep, and even perl. I am looking for something I can throw on a VM on my personal laptop and mess around with.... (5 Replies)
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2. Shell Programming and Scripting
I have a fixed length file a.txt that looks like
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b@ b00... (7 Replies)
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3. Shell Programming and Scripting
Hi folks,
I have a scenario to convert the update statements into insert statements using shell script (awk, sed...) or in database using regex.
I have a bunch of update statements with all columns in a file which I need to convert into insert statements.
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4. Shell Programming and Scripting
I've input as ,
abcd|
ef
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Anyone please give the solution. (5 Replies)
Discussion started by: jinixvimal
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5. Shell Programming and Scripting
Dear All,
The row_eff_tmstp (4th field) and row_expr_tmstp(5th field) in below data represents. If row_expr_tmstp is less than row_eff_tmstp I should replace that as null. First record is header record.
I/P
------
DD04 DD040001 DD040001 NO NO NONE ... (1 Reply)
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6. Shell Programming and Scripting
Hi,
I am running a script sample.sh in bash environment .In the script i am using sed and awk commands which when executed individually from terminal they are getting executed normally but when i give these sed and awk commands in the script it is giving the below errors :-
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7. UNIX for Dummies Questions & Answers
Hi All,
I am new to unix.
In this forum some days back, I have read something like below:
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2) Do not use awk if sed can do your work.
.
.
.
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8. Shell Programming and Scripting
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My record looks something like this
I need to add 100 at the beginning of each record.
o/p should be (2 Replies)
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9. UNIX for Advanced & Expert Users
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10. UNIX for Advanced & Expert Users
Hey all,
Can I put sed command inside the awk action ?? If not then can i do grep in the awk action ??
For ex:
awk '$1=="174" { ppid=($2) ; sed -n '/$ppid/p' tempfind.txt ; }' tempfind.txt
Assume: 174 is string.
Assume: tempfind.txt is used for awk and sed both.
tempfind.txt... (11 Replies)
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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)
