ksh has a built-in random number generator. It's performance is not spectacular, but it is probably good enough for your purposes. It will generate random numbers in the range of 0 to 32767. You will need a different range. Use this technique:
Warning: do not use the modulus operation to convert the range. The above code is using the high order bits of the initial random number while the modulus operation would use the low order bits. So you would generate a random number between 0 and 14999. Then you would add one to get a line number between 1 and 15000. Then just use sed or something to retrieve that line. (Or something like that. I got lost in your math...I don't understand how picking 50 cities gives us 1000 picks. )
But this assumes that it is ok to pick the lsame line twice from the file every now and then. Many times that is exactly what you want. But a few times, duplicates are not ok. Suppose that there were 52 lines in the file representing the cards in a deck of playing cards. If you want to generate a random poker hand, you must eliminate duplicates. In this case, you would first generate a number between 1 and 52 and, as before, you would retrieve the selected line. But then you would use sed to delete that line leaving only 51 lines in the file. For your second card, you generate a random number between 1 and 51. And so on.
Hello people
I need to find a way to generate a file that contains the names of all *.jpg files that were generated after a specific date
The search should start in my current folder and recursively search inner folders
It would be best to list the file names one below the other in the output... (3 Replies)
Hi,
I want to write a script which can generate a kill list for killing process, program name start with f60.., which have been running for more than 8 hours, the list output should looks like:
kill -9 4444176
kill -9 4674520
kill -9 4454180
kill -9 4994523
Can anyone help how to write... (10 Replies)
How can I generate a list of numbers and place all of these numbers in a line-by-line into a file.
I am new to scripting actually.
0501000000 to 0509999999
i.e.
0501000000
0501000001
......
0509999999
set 02
0551000000 to 0559999999
i.e.
0551000000
0551000001
......
0559999999
... (3 Replies)
Reference post, https://www.unix.com/shell-programming-scripting/131307-incrementing-twist-please-help.html , I can generate a word list easily, by echo or for loop.
For example, with the echo command and word expect, I can list all 6 letters possibility (6X6X6X6X6X6=46656)
echo... (6 Replies)
Is there a tool that can diff a directory and generate a change list of files in that directory based on a previous snapshot on the directory?
For example
/etc/a.txt:changed
/etc/b.txt:removed
/etc/c.txt:added
Thanks! (1 Reply)
I just need to see any number of random files to see the owner, group and permissions information since all the files in the directory have the same permissions and ownership information. Is it possible just to list any 5 files without going thru the series of commands such as "ls -ltu | head -5"... (8 Replies)
I copied all JPEGs from my laptop to an external drive using
find . -name "*.jpg" -exec cp '{}' ./media/Backup/pictures \;
And then deleted all of them from my laptop.
Now, I realize that I need the folder path of all the original JPEGs as the path has the important information.
I dont... (1 Reply)
I manage an AIX OS 7.1 system on IBM Power 770.
I want to find out which directories/folders a particular user has read/write access to. How can I cleanly create a list of all directories on the system that a user has access to.. Does this make sense?
Thanks in Advance, NEWB:rolleyes: (3 Replies)
Need to use dd to generate a large file from a sample file of random data. This is because I don't have /dev/urandom.
I create a named pipe then:
dd if=mynamed.fifo do=myfile.fifo bs=1024 count=1024
but when I cat a file to the fifo that's 1024 random bytes:
cat randomfile.txt >... (7 Replies)
Heyas
I want to list passed arguments and make an incrementing 'marker'.
That 'marker' should be a letter between a-z, in proper order.
I'm not aware of a seq pendant, so i tried it with this:
C=141
list=""
while ];do
printf \\$C
list+=" \\$C"
C=$((C+1))
done
echo... (3 Replies)
Discussion started by: sea
3 Replies
LEARN ABOUT SUSE
pwgen
PWGEN(1) General Commands Manual PWGEN(1)NAME
pwgen - generate pronounceable passwords
SYNOPSIS
pwgen [ OPTION ] [ pw_length ] [ num_pw ]
DESCRIPTION
The pwgen program generates passwords which are designed to be easily memorized by humans, while being as secure as possible. Human-memo-
rable passwords are never going to be as secure as completely completely random passwords. In particular, passwords generated by pwgen
without the -s option should not be used in places where the password could be attacked via an off-line brute-force attack. On the other
hand, completely randomly generated passwords have a tendency to be written down, and are subject to being compromised in that fashion.
The pwgen program is designed to be used both interactively, and in shell scripts. Hence, its default behavior differs depending on
whether the standard output is a tty device or a pipe to another program. Used interactively, pwgen will display a screenful of passwords,
allowing the user to pick a single password, and then quickly erase the screen. This prevents someone from being able to "shoulder surf"
the user's chosen password.
When standard output (stdout) is not a tty, pwgen will only generate one password, as this tends to be much more convenient for shell
scripts, and in order to be compatible with previous versions of this program.
In addition, for backwards compatibility reasons, when stdout is not a tty and secure password generation mode has not been requested,
pwgen will generate less secure passwords, as if the -0A options had been passed to it on the command line. This can be overriden using
the -nc options. In the future, the behavior when stdout is a tty may change, so shell scripts using pwgen should explicitly specify the
-nc or -0A options. The latter is not recommended for security reasons, since such passwords are far too easy to guess.
OPTIONS -0, --no-numerals
Don't include numbers in the generated passwords.
-1 Print the generated passwords one per line.
-A, --no-capitalize
Don't bother to include any capital letters in the generated passwords.
-a, --alt-phonics
This option doesn't do anything special; it is present only for backwards compatibility.
-B, --ambiguous
Don't use characters that could be confused by the user when printed, such as 'l' and '1', or '0' or 'O'. This reduces the number
of possible passwords significantly, and as such reduces the quality of the passwords. It may be useful for users who have bad
vision, but in general use of this option is not recommended.
-c, --capitalize
Include at least one capital letter in the password. This is the default if the standard output is a tty device.
-C Print the generated passwords in columns. This is the default if the standard output is a tty device.
-N, --num-passwords=num
Generate num passwords. This defaults to a screenful if passwords are printed by columns, and one password.
-n, --numerals
Include at least one number in the password. This is the default if the standard output is a tty device.
-H, --sha1=/path/to/file[#seed]
Will use the sha1's hash of given file and the optional seed to create password. It will allow you to compute the same password
later, if you remember the file, seed, and pwgen's options used. ie: pwgen -H ~/your_favorite.mp3#your@email.com gives a list of
possibles passwords for your pop3 account, and you can ask this list again and again.
WARNING: The passwords generated using this option are not very random. If you use this option, make sure the attacker can not
obtain a copy of the file. Also, note that the name of the file may be easily available from the ~/.history or ~/.bash_history
file.
-h, --help
Print a help message.
-s, --secure
Generate completely random, hard-to-memorize passwords. These should only be used for machine passwords, since otherwise it's
almost guaranteed that users will simply write the password on a piece of paper taped to the monitor...
-v, --no-vowels
Generate random passwords that do not contain vowels or numbers that might be mistaken for vowels. It provides less secure pass-
words to allow system administrators to not have to worry with random passwords accidentally contain offensive substrings.
-y, --symbols
Include at least one special character in the password.
AUTHOR
This version of pwgen was written by Theodore Ts'o <tytso@alum.mit.edu>. It is modelled after a program originally written by Brandon S.
Allbery, and then later extensively modified by Olaf Titz, Jim Lynch, and others. It was rewritten from scratch by Theodore Ts'o because
the original program was somewhat of a hack, and thus hard to maintain, and because the licensing status of the program was unclear.
SEE ALSO passwd(1)pwgen version 2.05 January 2006 PWGEN(1)