How to generate a random integer with specific range(for example, from 1 to 1000)?
Also, how to convert a floating point number into a integer? (2 Replies)
Hello All...
Can someone help me generate a random password which will be 7 characters long which contains alpha-numeric characters using shell script.
I am looking to store the output of the script that generates the password to a variable within a script and use it as the password.
... (5 Replies)
Hi, Guz!
I'm working on a scripts compiler which needs a function to generate random strings. I think REGX may be a good solution to restrict the string format. Before DIYing I'd like asking for any existing libs or codes.
Any help will be appreciated! (7 Replies)
I saw this formula to generate random number between two specified values in shell script.the following.
$(((RANDOM%(max-min+divisibleBy))/divisibleBy*divisibleBy+min))
Give a example in book.
Generate random number between 6 and 30.like this.
$(((RANDOM%30/3+1)*3))
But I have a... (1 Reply)
Hi
I am new to expect. Please if any one can help on my issue its really appreciable. here is my issue:
I want expect script for random passwords and random commands generation.
please can anyone help me?
Many Thanks in advance (0 Replies)
hi guys,
I am writing a c program that generates a two dimensional array to make matrix and a vector of random numbers and perform multiplication. I can't figure out whats wrong with my code. It generates a matrix of random numbers but all the numbers in the vector array is same and so is the... (2 Replies)
i want to generate a random number through a script, and even if anyone reads the script, they wont be able to figure out what the random number is. only the person who setup the script would know it.
something like this could work: random
the full thread is here:
... (13 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)
Hi,
Is anybody experience generate a pair of random number by using awk command?
I wanna to generate a pair of random number (range from 1 to 4124) and repeats it 416 times.
Desired output
2 326
123 1256
341 14
3245 645
.
.
.
I did write the below command:
awk... (5 Replies)
Discussion started by: perl_beginner
5 Replies
LEARN ABOUT CENTOS
librrd
librrd(3) rrdtool librrd(3)NAME
librrd - RRD library functions
DESCRIPTION
librrd contains most of the functionality in RRDTool. The command line utilities and language bindings are often just wrappers around the
code contained in librrd.
This manual page documents the librrd API.
NOTE: This document is a work in progress, and should be considered incomplete as long as this warning persists. For more information
about the librrd functions, always consult the source code.
CORE FUNCTIONS
rrd_dump_cb_r(char *filename, int opt_header, rrd_output_callback_t cb, void *user)
In some situations it is necessary to get the output of "rrd_dump" without writing it to a file or the standard output. In such cases
an application can ask rrd_dump_cb_r to call an user-defined function each time there is output to be stored somewhere. This can be
used, to e.g. directly feed an XML parser with the dumped output or transfer the resulting string in memory.
The arguments for rrd_dump_cb_r are the same as for rrd_dump_opt_r except that the output filename parameter is replaced by the user-
defined callback function and an additional parameter for the callback function that is passed untouched, i.e. to store information
about the callback state needed for the user-defined callback to function properly.
Recent versions of rrd_dump_opt_r internally use this callback mechanism to write their output to the file provided by the user.
size_t rrd_dump_opt_cb_fileout(
const void *data,
size_t len,
void *user)
{
return fwrite(data, 1, len, (FILE *)user);
}
The associated call for rrd_dump_cb_r looks like
res = rrd_dump_cb_r(filename, opt_header,
rrd_dump_opt_cb_fileout, (void *)out_file);
where the last parameter specifies the file handle rrd_dump_opt_cb_fileout should write to. There's no specific condition for the
callback to detect when it is called for the first time, nor for the last time. If you require this for initialization and cleanup you
should do those tasks before and after calling rrd_dump_cr_r respectively.
UTILITY FUNCTIONS
rrd_random()
Generates random numbers just like random(). This further ensures that the random number generator is seeded exactly once per process.
rrd_add_ptr(void ***dest, size_t *dest_size, void *src)
Dynamically resize the array pointed to by "dest". "dest_size" is a pointer to the current size of "dest". Upon successful realloc(),
the "dest_size" is incremented by 1 and the "src" pointer is stored at the end of the new "dest". Returns 1 on success, 0 on failure.
type **arr = NULL;
type *elem = "whatever";
size_t arr_size = 0;
if (!rrd_add_ptr(&arr, &arr_size, elem))
handle_failure();
rrd_add_strdup(char ***dest, size_t *dest_size, char *src)
Like "rrd_add_ptr", except adds a "strdup" of the source string.
char **arr = NULL;
size_t arr_size = NULL;
char *str = "example text";
if (!rrd_add_strdup(&arr, &arr_size, str))
handle_failure();
rrd_free_ptrs(void ***src, size_t *cnt)
Free an array of pointers allocated by "rrd_add_ptr" or "rrd_add_strdup". Also frees the array pointer itself. On return, the source
pointer will be NULL and the count will be zero.
/* created as above */
rrd_free_ptrs(&arr, &arr_size);
/* here, arr == NULL && arr_size == 0 */
rrd_mkdir_p(const char *pathname, mode_t mode)
Create the directory named "pathname" including all of its parent directories (similar to "mkdir -p" on the command line - see mkdir(1)
for more information). The argument "mode" specifies the permissions to use. It is modified by the process's "umask". See mkdir(2) for
more details.
The function returns 0 on success, a negative value else. In case of an error, "errno" is set accordingly. Aside from the errors
documented in mkdir(2), the function may fail with the following errors:
EINVAL
"pathname" is "NULL" or the empty string.
ENOMEM
Insufficient memory was available.
any error returned by stat(2)
In contrast to mkdir(2), the function does not fail if "pathname" already exists and is a directory.
AUTHOR
RRD Contributors <rrd-developers@lists.oetiker.ch>
1.4.8 2013-05-23 librrd(3)