Hi,
From some time, we have noticed that our ascii files have started corrupting due to the presence of some random control characters (^@, ^M, ^H, ^D). The characters appear randomly on any file after the process that creates the file finishes. If we rerun the process, the files re creates... (0 Replies)
I have a directory of files that look like filename 001.ext, filename 002.ext, etc. I'd like to rename the files with unique random numbered names, so that the original filenames are stripped and the files are given a new, random number name. I'm not super new to UNIX, but I don't often use it for... (2 Replies)
hello
i just seeking for a simple way to make a shuffle by block of words in a line. no matter shell (sh/bash) or perl
should be like this:
the message (which is line of some file) splits to packs (packs are random 5-10 words in each) then making a new line inserting those packs in a random... (9 Replies)
I have a text file with 1000 lines, I want to randomly select 200 lines from it and print them as output. How do I go about doing that? Thanks! (7 Replies)
I have two files containing hundreds of different sequences with the same Identifiers (ID-001, ID-002, etc.,), something like this:
Infile1:
ID-001 ATGGGAGCGGGGGCGTCTGCCTTGAGGGGAGAGAAGCTAGATACA
ID-002 ATGGGAGCGGGGGCGTCTGTTTTGAGGGGAGAGAAGCTAGATACA
ID-003... (18 Replies)
Is there any way to place each even column name infront of its odd column using awk or others?
input
Ab name MGH26 B04 MGH26 B05
output
name_Ab B04_MGH26 B05_MGH26 (4 Replies)
Hi Folks,
I have a text file with a thousand lines consisting of words or a group of words separated by commas.
I would like to randomize / shuffle the words on each line.
Eg; file.txt
Linux,Open,Free,Awesome,Best Things in Life,The Greatest
Laptop,PC,Tablet,Home Computers,Digital... (2 Replies)
Hi,
Is there any way I can shuffle the numbers randomly. I have been trying to google and I found lots of 'generator' but is it possible to find the background logic to create randomness?
Thanks, (3 Replies)
Discussion started by: Indra2011
3 Replies
LEARN ABOUT OSX
urandom
RANDOM(4) BSD Kernel Interfaces Manual RANDOM(4)NAME
random , urandom -- random data source devices.
SYNOPSIS
pseudo-device random
DESCRIPTION
The random device produces uniformly distributed random byte values of potentially high quality.
To obtain random bytes, open /dev/random for reading and read from it.
To add entropy to the random generation system, open /dev/random for writing and write data that you believe to be somehow random.
/dev/urandom is a compatibility nod to Linux. On Linux, /dev/urandom will produce lower quality output if the entropy pool drains, while
/dev/random will prefer to block and wait for additional entropy to be collected. With Yarrow, this choice and distinction is not necessary,
and the two devices behave identically. You may use either.
OPERATION
The random device implements the Yarrow pseudo random number generator algorithm and maintains its entropy pool. Additional entropy is fed
to the generator regularly by the SecurityServer daemon from random jitter measurements of the kernel. SecurityServer is also responsible
for periodically saving some entropy to disk and reloading it during startup to provide entropy in early system operation.
You may feed additional entropy to the generator by writing it to the random device, though this is not required in a normal operating envi-
ronment.
LIMITATIONS AND WARNINGS
Yarrow is a fairly resilient algorithm, and is believed to be resistant to non-root. The quality of its output is however dependent on regu-
lar addition of appropriate entropy. If the SecurityServer system daemon fails for any reason, output quality will suffer over time without
any explicit indication from the random device itself.
Paranoid programmers can counteract this risk somewhat by collecting entropy of their choice (e.g. from keystroke or mouse timings) and seed-
ing it into random directly before obtaining important random numbers.
FILES
/dev/random
/dev/urandom
HISTORY
A random device appeared in the Linux operating system.
Darwin September 6, 2001 Darwin