:D can anyone tell me how to make this script continue after the *)
I have been reading C and shell scripting and am confused.. I tried to impliment a while (1) and a continue after the *) but I keep getting end of file error..! also there a few different loops that I am not sure which type to... (3 Replies)
Hi
Following is the code . When I give input as Bangalore,its dospalying Welcome to Hitech City. But say , if I select Delhi or US, its not displaying the corresponding message. Its still says Welcome to Hitech City.
Seems that it not entering in the elif part. Please suggest.
#!... (4 Replies)
I want to write a shell script which clones a file, example the name of the file to be cloned is "es" and I want its clone have the name "es1", "es2", "es3", and so on.
Then another program called service needs the former clone as input,
for example service up /home/es1, service up /home/es2... (4 Replies)
Hi,
I have a unix shell script that I use to run the jobs, which internally calls a number of other jobs and outputs a log file. I want to call another shell script in the main script that constantly reads the log file that gets appended and emails the user upon each job completion.
for... (5 Replies)
Hi Gurus
I have to write a script which does something like this
/usr/local/gpg2/bin/GPG2 -o arch_696354351_1_23.dbf -d arch_696354351_1_23.dbf.gpg
/usr/local/gpg2/bin/GPG2 -o arch_696354351_1_24.dbf -d arch_696354351_1_24.dbf.gpg
/usr/local/gpg2/bin/GPG2 -o arch_696354351_1_25.dbf... (8 Replies)
Hi all,
i got 2 text file.
file.txt
value.txt
i want use C shell script to write out
while both of the file got different limit....how i going to write it in 1 while loop? (4 Replies)
Hello World
I need to create a script to verify ports are open from a new jump off node to access over 200 different servers.
I did a little research and put together this code:
!/bin/sh
exec 4<nodes.dat
while read sys <& 4
do
# PING TEST
echo "$sys"
ping $sys 1
# Example of... (1 Reply)
Hi All
I want to make a script in which i can print prstat command output to a file in regular interval of 1 second
I am using below script for the same
dat=`date '+%d%m%y'`
echo "###########################################################" >>prstat-$dat
date >>prstat-$dat
prstat 1 1... (3 Replies)
Having issues with an expect script. I've been scripting bash, python, etc... for a couple years now, but just started to try and use Expect. Trying to create a script that takes in some arguments, and then for now, just runs a pwd command(for testing, final will be command I pass).
Here is... (0 Replies)
Hi,
I am newer to UNIX scripting. Here is what I am trying to accomplish:
I want to log a timestamp and a row count for a spcific file, out to another file.
Below is my script. WhenI run it, it says that line 6 is missing a ']' which I don't see how, and then echos File Does Not Exist... (5 Replies)
Discussion started by: eanolan
5 Replies
LEARN ABOUT REDHAT
random
RANDOM(4) Linux Programmer's Manual RANDOM(4)NAME
random, urandom - kernel random number source devices
DESCRIPTION
The character special files /dev/random and /dev/urandom (present since Linux 1.3.30) provide an interface to the kernel's random number
generator. File /dev/random has major device number 1 and minor device number 8. File /dev/urandom has major device number 1 and minor
device number 9.
The random number generator gathers environmental noise from device drivers and other sources into an entropy pool. The generator also
keeps an estimate of the number of bit of the noise in the entropy pool. From this entropy pool random numbers are created.
When read, the /dev/random device will only return random bytes within the estimated number of bits of noise in the entropy pool.
/dev/random should be suitable for uses that need very high quality randomness such as one-time pad or key generation. When the entropy
pool is empty, reads to /dev/random will block until additional environmental noise is gathered.
When read, /dev/urandom device will return as many bytes as are requested. As a result, if there is not sufficient entropy in the entropy
pool, the returned values are theoretically vulnerable to a cryptographic attack on the algorithms used by the driver. Knowledge of how to
do this is not available in the current non-classified literature, but it is theoretically possible that such an attack may exist. If this
is a concern in your application, use /dev/random instead.
CONFIGURING
If your system does not have /dev/random and /dev/urandom created already, they can be created with the following commands:
mknod -m 644 /dev/random c 1 8
mknod -m 644 /dev/urandom c 1 9
chown root:root /dev/random /dev/urandom
When a Linux system starts up without much operator interaction, the entropy pool may be in a fairly predictable state. This reduces the
actual amount of noise in the entropy pool below the estimate. In order to counteract this effect, it helps to carry entropy pool informa-
tion across shut-downs and start-ups. To do this, add the following lines to an appropriate script which is run during the Linux system
start-up sequence:
echo "Initializing kernel random number generator..."
# Initialize kernel random number generator with random seed
# from last shut-down (or start-up) to this start-up. Load and
# then save 512 bytes, which is the size of the entropy pool.
if [ -f /var/random-seed ]; then
cat /var/random-seed >/dev/urandom
fi
dd if=/dev/urandom of=/var/random-seed count=1
Also, add the following lines in an appropriate script which is run during the Linux system shutdown:
# Carry a random seed from shut-down to start-up for the random
# number generator. Save 512 bytes, which is the size of the
# random number generator's entropy pool.
echo "Saving random seed..."
dd if=/dev/urandom of=/var/random-seed count=1
FILES
/dev/random
/dev/urandom
AUTHOR
The kernel's random number generator was written by Theodore Ts'o (tytso@athena.mit.edu).
SEE ALSO
mknod (1)
RFC 1750, "Randomness Recommendations for Security"
Linux 1997-08-01 RANDOM(4)