08-06-2009
How to Pick Random records from a large file
Hi,
I have a huge file say with 2000000 records. The file has 42 fields. I would like to pick randomly 1000 records from this huge file. Can anyone help me how to do this?
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LEARN ABOUT CENTOS
gethugepagesizes
GETHUGEPAGESIZES(3) Library Functions Manual GETHUGEPAGESIZES(3)
NAME
gethugepagesizes - Get the system supported huge page sizes
SYNOPSIS
#include <hugetlbfs.h>
int gethugepagesizes(long pagesizes[], int n_elem);
DESCRIPTION
The gethugepagesizes() function returns either the number of system supported huge page sizes or the sizes themselves. If pagesizes is
NULL and n_elem is 0, then the number of huge pages the system supports is returned. Otherwise, pagesizes is filled with at most n_elem
page sizes.
RETURN VALUE
On success, either the number of huge page sizes supported by the system or the number of huge page sizes stored in pagesizes is returned.
On failure, -1 is returned and errno is set appropriately.
ERRORS
EINVAL n_elem is less than zero or n_elem is greater than zero and pagesizes is NULL.
Also see opendir(3) for other possible values for errno. This error occurs when the sysfs directory exists but cannot be opened.
NOTES
This call will return all huge page sizes as reported by the kernel. Not all of these sizes may be usable by the programmer since mount
points may not be available for all sizes. To test whether a size will be usable by libhugetlbfs, hugetlbfs_find_path_for_size() can be
called on a specific size to see if a mount point is configured.
SEE ALSO
oprofile(1), opendir(3), hugetlbfs_find_path_for_size(3), libhugetlbfs(7)
AUTHORS
libhugetlbfs was written by various people on the libhugetlbfs-devel mailing list.
October 10, 2008 GETHUGEPAGESIZES(3)