04-20-2007
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
I have a flat file and need to count no of records in the file less the header and the trailer record.
I would appreciate any and all asistance
Thanks
Hadi Lalani (2 Replies)
Discussion started by: guiguy
2 Replies
2. UNIX for Dummies Questions & Answers
hi,
How to check a given file for a string and if it's not found, exit out ofthe script?
e.g. a file Test123 is there whose header begins with #bt and trailer begins with #ed.
I have to check if the header and trailer matches as above and if not, exit out of the script.
How can we do it in... (2 Replies)
Discussion started by: er_ashu
2 Replies
3. Shell Programming and Scripting
Dear all,
I have a file created in the name sample.txt in UNIX with header and footer. How to insert a required string (for example "FILE1") in the header part after the file has been created. What kind of command can i use to do the same.
Thanks in advance
Hari (3 Replies)
Discussion started by: Hari123
3 Replies
4. Shell Programming and Scripting
i have .DAT file FILE1.DAT
1200910270040625
2123456789 J123456 ABC
2123456789 K123456 ABC
2222222222 L123456 DEF
2333333333 M12345 GHI
30000004
My outfile FILE2.TXT should have like this, I need the header value as ie (1200910270040625 ) body rows remove the duplicate rows and the... (2 Replies)
Discussion started by: kshuser
2 Replies
5. Shell Programming and Scripting
Hi,
I'm having trouble pulling out columns where the headers match a file of key ID's I'm interested in and was looking for some help.
file1.txt
I
Name
34
56
84
350
790
1215
1919
7606
9420
file2.txt
I Name 1 1 2 2 3 3 ... 34 34... 56 56... 84 84... 350 350...
M 1 A A A A... (20 Replies)
Discussion started by: flotsam
20 Replies
6. Shell Programming and Scripting
awk experts,
I have a big file of 4000 columns with header. Would like to print the columns with string value of "Commands" in header. File has "," separator. This file is on ESX host with Bash.
Thanks,
Arv (21 Replies)
Discussion started by: arv_cds
21 Replies
7. Programming
I get this error when I try to compile following C program
#include <stdio.h>
#include <strings.h>
#define LEN 80
int main(void)
{
int mess, flag = 1;
int first = 0, last = 0;
printf("Enter a message: ");
gets(mess);
if (strlen(mess) > LEN)
... (3 Replies)
Discussion started by: solaris_user
3 Replies
8. UNIX for Dummies Questions & Answers
Hi There!
I am saving the file count of all files in a directory to an output file using:
wc -l * > FileCount.txt
I get:
114 G4SXORD
3 G4SXORH
0 G4SXORP
117 total
But this count includes header and footer. I want to subtract 2 from the count and get
... (7 Replies)
Discussion started by: gagan8877
7 Replies
9. Shell Programming and Scripting
What I'm trying to accomplish. I receive a Header and Detail file for daily processing. The detail file comes first which holds data, the header is a receipt of the detail file and has the detail files record count. Before processing the detail file I would like to put a wrapper around another... (4 Replies)
Discussion started by: pone2332
4 Replies
10. Shell Programming and Scripting
I have a large dataset with following structure;
C 0001 Carbon
D SAR001 methane
D SAR002 ethane
D SAR003 propane
D SAR004 butane
D SAR005 pentane
C 0002 Hydrogen
C 0003 Nitrogen
C 0004 Oxygen
D SAR011 ozone
D SAR012 super oxide
C 0005 Sulphur
D SAR013... (3 Replies)
Discussion started by: Syeda Sumayya
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)