on my desktop i am using the kde rotating desktop image option. this rotates images randomly every half hour. now, i would like to write an html file which will have an inline frame with some text, maybe system messages, or my friends live journal thati read alot, or unix.com! however, i dont want... (1 Reply)
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 want to take the below data, and have it output to file only the STMC#/(IP address) and the "there are X number of updates to install" lines for each machine. I know it's easy, but Im a beginner in BASH stuff, my solution would probably take way too many lines to do something easy.Thanks!
... (5 Replies)
Hi there, I have a text file with several colums separated by "|;#" I need to search the file extracting all columns starting with the value of "1" or "2" saving in a separate file just the first 7 columns of each row maching the criteria, with replacement of the saparators in the nearly created... (4 Replies)
i have a file in following format
1 32 3
4 6 4
4 45 1
45 4 61
54 66 4
5 65 51
56 65 1
12 32 85
now here the total number of lines are 8(they vary each time)
Now i want to select only those lines in which the values... (6 Replies)
What I have are two text files that I need to shuffle randomly, but I need the two files to be randomly shuffled the same way. I have heard of shuf but I do not know how to use it for two files. Maybe there is also an easy/simple awk command I do not know about that could handle this problem.
... (3 Replies)
Hello,
This is my code:
nb_lignes=`wc -l $1 | cut -d " " -f1`
for i in $(seq $nb_lignes)
do
m=`head $1 -n $i | tail -1`
//command
done
Please how can i change it to get Get 20% of lines in File randomly to apply "command" on each line ? 20% or 40% or 60 % (it's a parameter)
Thank you. (15 Replies)
Hi
I need to select lines from a txt file, I have got a line starting with ZMIO:MSISDN= and after a few line I have another line starting with 'MOBILE STATION ISDN NUMBER' and another one starting with 'VLR-ADDRESS' I need to copy these three lines as three different columns in a separate... (3 Replies)
Dear Folks
I have one column of 15000 lines and want to select randomly 5000 of them in five different times without replacement. I am aware that command 'shuf' and 'sort -R' could select randomly those lines but I am not sure how could I avoid the replacement of selection line. Does anyone have... (10 Replies)
hi all,
trying this using shell/bash with sed/awk/grep
I have two files, one containing one column, the other containing multiple columns (comma delimited).
file1.txt
abc12345
def12345
ghi54321
...
file2.txt
abc1,text1,texta
abc,text2,textb
def123,text3,textc
gh,text4,textd... (6 Replies)
Discussion started by: shogun1970
6 Replies
LEARN ABOUT REDHAT
srand
RAND(3) Linux Programmer's Manual RAND(3)NAME
rand, srand - random number generator.
SYNOPSIS
#include <stdlib.h>
int rand(void);
void srand(unsigned int seed);
DESCRIPTION
The rand() function returns a pseudo-random integer between 0 and RAND_MAX.
The srand() function sets its argument as the seed for a new sequence of pseudo-random integers to be returned by rand(). These sequences
are repeatable by calling srand() with the same seed value.
If no seed value is provided, the rand() function is automatically seeded with a value of 1.
RETURN VALUE
The rand() function returns a value between 0 and RAND_MAX. The srand() returns no value.
NOTES
The versions of rand() and srand() in the Linux C Library use the same random number generator as random() and srandom(), so the lower-
order bits should be as random as the higher-order bits. However, on older rand() implementations, the lower-order bits are much less ran-
dom than the higher-order bits.
In Numerical Recipes in C: The Art of Scientific Computing (William H. Press, Brian P. Flannery, Saul A. Teukolsky, William T. Vetterling;
New York: Cambridge University Press, 1992 (2nd ed., p. 277)), the following comments are made:
"If you want to generate a random integer between 1 and 10, you should always do it by using high-order bits, as in
j=1+(int) (10.0*rand()/(RAND_MAX+1.0));
and never by anything resembling
j=1+(rand() % 10);
(which uses lower-order bits)."
Random-number generation is a complex topic. The Numerical Recipes in C book (see reference above) provides an excellent discussion of
practical random-number generation issues in Chapter 7 (Random Numbers).
For a more theoretical discussion which also covers many practical issues in depth, please see Chapter 3 (Random Numbers) in Donald E.
Knuth's The Art of Computer Programming, volume 2 (Seminumerical Algorithms), 2nd ed.; Reading, Massachusetts: Addison-Wesley Publishing
Company, 1981.
CONFORMING TO
SVID 3, BSD 4.3, ISO 9899
SEE ALSO random(3), srandom(3), initstate(3), setstate(3)GNU 1995-05-18 RAND(3)