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 LINUX
psc
PSC(1) General Commands Manual PSC(1)NAME
psc - prepare sc files
SYNOPSIS
psc [-fLkrSPv] [-s cell] [-R n] [-C n] [-n n] [-d c]
DESCRIPTION
Psc is used to prepare data for input to the spreadsheet calculator sc(1). It accepts normal ascii data on standard input. Standard out-
put is a sc file. With no options, psc starts the spreadsheet in cell A0. Strings are right justified. All data on a line is entered on
the same row; new input lines cause the output row number to increment by one. The default delimiters are tab and space. The column for-
mats are set to one larger than the number of columns required to hold the largest value in the column.
OPTIONS -f Omit column width calculations. This option is for preparing data to be merged with an existing spreadsheet. If the option is not
specified, the column widths calculated for the data read by psc will override those already set in the existing spreadsheet.
-L Left justify strings.
-k Keep all delimiters. This option causes the output cell to change on each new delimiter encountered in the input stream. The
default action is to condense multiple delimiters to one, so that the cell only changes once per input data item.
-r Output the data by row first then column. For input consisting of a single column, this option will result in output of one row
with multiple columns instead of a single column spreadsheet.
-s cell
Start the top left corner of the spreadsheet in cell. For example, -s B33 will arrange the output data so that the spreadsheet
starts in column B, row 33.
-R n Increment by n on each new output row.
-C n Increment by n on each new output column.
-n n Output n rows before advancing to the next column. This option is used when the input is arranged in a single column and the
spreadsheet is to have multiple columns, each of which is to be length n.
-d c Use the single character c as the delimiter between input fields.
-P Plain numbers only. A field is a number only when there is no imbedded [-+eE].
-S All numbers are strings.
-v Print the version of psc
SEE ALSO sc(1)AUTHOR
Robert Bond
PSC 7.16 19 September 2002 PSC(1)