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 PHP
mysqli_prepare
MYSQLI_PREPARE(3) 1 MYSQLI_PREPARE(3)mysqli::prepare - Prepare an SQL statement for execution
Object oriented style
SYNOPSIS
mysqli_stmt mysqli::prepare (string $query)
DESCRIPTION
Procedural style
mysqli_stmt mysqli_prepare (mysqli $link, string $query)
Prepares the SQL query, and returns a statement handle to be used for further operations on the statement. The query must consist of a
single SQL statement.
The parameter markers must be bound to application variables using mysqli_stmt_bind_param(3) and/or mysqli_stmt_bind_result(3) before exe-
cuting the statement or fetching rows.
PARAMETERS
o $
link -Procedural style only: A link identifier returned by mysqli_connect(3) or mysqli_init(3)
o $query
- The query, as a string.
Note
You should not add a terminating semicolon or g to the statement.
This parameter can include one or more parameter markers in the SQL statement by embedding question mark ( ?) characters at the
appropriate positions.
Note
The markers are legal only in certain places in SQL statements. For example, they are allowed in the VALUES() list of an
INSERT statement (to specify column values for a row), or in a comparison with a column in a WHERE clause to specify a com-
parison value.
However, they are not allowed for identifiers (such as table or column names), in the select list that names the columns to
be returned by a SELECT statement, or to specify both operands of a binary operator such as the = equal sign. The latter
restriction is necessary because it would be impossible to determine the parameter type. It's not allowed to compare marker
with NULL by ? IS NULL too. In general, parameters are legal only in Data Manipulation Language (DML) statements, and not in
Data Definition Language (DDL) statements.
RETURN VALUES mysqli_prepare(3) returns a statement object or FALSE if an error occurred.
EXAMPLES
Example #1
mysqli::prepare example
Object oriented style
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s
", mysqli_connect_error());
exit();
}
$city = "Amersfoort";
/* create a prepared statement */
if ($stmt = $mysqli->prepare("SELECT District FROM City WHERE Name=?")) {
/* bind parameters for markers */
$stmt->bind_param("s", $city);
/* execute query */
$stmt->execute();
/* bind result variables */
$stmt->bind_result($district);
/* fetch value */
$stmt->fetch();
printf("%s is in district %s
", $city, $district);
/* close statement */
$stmt->close();
}
/* close connection */
$mysqli->close();
?>
Procedural style
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s
", mysqli_connect_error());
exit();
}
$city = "Amersfoort";
/* create a prepared statement */
if ($stmt = mysqli_prepare($link, "SELECT District FROM City WHERE Name=?")) {
/* bind parameters for markers */
mysqli_stmt_bind_param($stmt, "s", $city);
/* execute query */
mysqli_stmt_execute($stmt);
/* bind result variables */
mysqli_stmt_bind_result($stmt, $district);
/* fetch value */
mysqli_stmt_fetch($stmt);
printf("%s is in district %s
", $city, $district);
/* close statement */
mysqli_stmt_close($stmt);
}
/* close connection */
mysqli_close($link);
?>
The above examples will output:
Amersfoort is in district Utrecht
SEE ALSO mysqli_stmt_execute(3), mysqli_stmt_fetch(3), mysqli_stmt_bind_param(3), mysqli_stmt_bind_result(3), mysqli_stmt_close(3).
PHP Documentation Group MYSQLI_PREPARE(3)