07-19-2009
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
i don't get what's wrong here. i'm writing a shell script that takes 1 argument (a number) from the command-line, but it's throwing an error:
Syntax error: Bad for loop variable
doesn't make much sense
for (( i = 1; i = ${1}; i++ )) # error points to this line everytime
do
echo... (9 Replies)
Discussion started by: visitorQ
9 Replies
2. Shell Programming and Scripting
Hi,
I have the following script (compile_mercury) and I get this error: I have no idea why...and I have written this script completely in linux (bash) and not in windows.
****************
./compile_mercury: line 136: syntax error near unexpected token `done'
./compile_mercury: line 136:... (1 Reply)
Discussion started by: habzone2007
1 Replies
3. Shell Programming and Scripting
Hi guys,
I'm trying to loop through a number of files that is set by whatever is in a field.
eg.
The idea is to split FILELIST down into fields, it could contain 1 - 999 fields and it's bar delimited.
I thought simple, count the number of fields in the field and then loop... (1 Reply)
Discussion started by: Peejay
1 Replies
4. Shell Programming and Scripting
I'd like a shell-script syntax checker that can detect at least the following errors, and more:
1. Variable $VAR used but VAR has not been defined.
2. Variable VAR defined but never used.
3. Use of unquoted variables which might break external commands e.g. SOMETHING in: value=`grep $SOMETHING... (5 Replies)
Discussion started by: garethr
5 Replies
5. Shell Programming and Scripting
hi,
I have to use for loop in my script. The below code is providing an output,
1,2,3,4,5..n. But i need to display the values one by one eg: it has to display the first value then exit from the loop and display the second value then exit till n(last value).
for i in 1,2,3,4,5..n
do ... (2 Replies)
Discussion started by: sreelu
2 Replies
6. UNIX for Dummies Questions & Answers
%%%%% (3 Replies)
Discussion started by: lucasvs
3 Replies
7. Shell Programming and Scripting
I am trying to run a menu option though IF loops. I keep getting errors not allowed the menu to be processed correctly. Currently it will accept the first 2 statements but then crash on the 3rd. The 2nd and 3rd have the same syntax, so I do not understand why it breaks.
#!/bin/bash
while... (4 Replies)
Discussion started by: Ironguru
4 Replies
8. UNIX for Dummies Questions & Answers
I am using simple for loop, but getting syntax error when I run the code
code
#!/bin/ksh
pls enter number
read n
for(i=1; i<=n; i++)
do
echo $i
done
syntax error
+ pls enter number
+ read n (5 Replies)
Discussion started by: stew
5 Replies
9. Shell Programming and Scripting
I have a shell script which has this while loop line
"while read tblName xx; do..."
I understand how while loop works but don't know what does this xx stands for? (1 Reply)
Discussion started by: later_troy
1 Replies
10. Shell Programming and Scripting
I like to “optimize” / make more like a real program my bash script by replacing repetitious code which utilizes positional parameters.
I am having two issues I cannot solve and would appreciate some assistance with resolving them.
a) how to modify the whiptail checklist... (3 Replies)
Discussion started by: annacreek
3 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)