Array size Post: 5916

Sponsored Content

Top Forums Programming Array size Post 5916 by rwb1959 on Sunday 26th of August 2001 07:29:05 PM

08-26-2001

Registered User

limits on array sizes

The answer is No and Yes. Theoretically,
there is no limit. However, the kernel may be
configured to allow only a limited amount
of memory per process and/or user. You can find
out what the system resource limits are on your
particular UNIX system using the system
call "getrlimit()" (man section 2). The following
C program can be compiled and run as any ordinary
user...

================== SNIP ========================
/*
* Filename - getlimits.c
*
* Description - display system resource limits and
* test allocating large blocks of memory.
*
*/

#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>

main(int argc, char **argv)
{
struct rlimit rlim;
void *p;

getrlimit(RLIMIT_CPU, &rlim);
printf("CPU: cur - %ld max - %ld\n", rlim.rlim_cur, rlim.rlim_max);
getrlimit(RLIMIT_FSIZE, &rlim);
printf("FSIZE: cur - %ld max - %ld\n", rlim.rlim_cur, rlim.rlim_max);
getrlimit(RLIMIT_DATA, &rlim);
printf("DATA: cur - %ld max - %ld\n", rlim.rlim_cur, rlim.rlim_max);
getrlimit(RLIMIT_STACK, &rlim);
printf("STACK: cur - %ld max - %ld\n", rlim.rlim_cur, rlim.rlim_max);
getrlimit(RLIMIT_CORE, &rlim);
printf("CORE: cur - %ld max - %ld\n", rlim.rlim_cur, rlim.rlim_max);
#ifdef LINUX
getrlimit(RLIMIT_RSS, &rlim);
printf("RSS: cur - %ld max - %ld\n", rlim.rlim_cur, rlim.rlim_max);
getrlimit(RLIMIT_NPROC, &rlim);
printf("NPROC: cur - %ld max - %ld\n", rlim.rlim_cur, rlim.rlim_max);
#else
getrlimit(RLIMIT_VMEM, &rlim);
printf("VMEM: cur - %ld max - %ld\n", rlim.rlim_cur, rlim.rlim_max);
getrlimit(RLIMIT_AS, &rlim);
printf("AS: cur - %ld max - %ld\n", rlim.rlim_cur, rlim.rlim_max);
#endif
getrlimit(RLIMIT_NOFILE, &rlim);
printf("NOFILE: cur - %ld max - %ld\n", rlim.rlim_cur, rlim.rlim_max);
#ifdef LINUX
getrlimit(RLIMIT_MEMLOCK, &rlim);
printf("MEMLOCK: cur - %ld max - %ld\n", rlim.rlim_cur, rlim.rlim_max);
#endif

if((p = malloc(100000000)) == NULL)
{
printf("malloc 100M failed\n");
}
else
{
printf("malloc 100M succeeded\n");
}
if(p) free(p);
if((p = malloc(500000000)) == NULL)
{
printf("malloc 500M failed\n");
}
else
{
printf("malloc 500M succeeded\n");
}
if(p) free(p);
return 0;
}

================== SNIP ========================

The output (on Linux) should look somthing like...

$ getlimits
CPU: cur - 2147483647 max - 2147483647
FSIZE: cur - 2147483647 max - 2147483647
DATA: cur - 2147483647 max - 2147483647
STACK: cur - 8388608 max - 2147483647
CORE: cur - 1024000000 max - 2147483647
RSS: cur - 2147483647 max - 2147483647
NPROC: cur - 2048 max - 2048
NOFILE: cur - 1024 max - 1024
MEMLOCK: cur - 2147483647 max - 2147483647
malloc 100M succeeded
malloc 500M succeeded

rwb1959

View Public Profile for rwb1959

Find all posts by rwb1959

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

MAX SIZE ARRAY Can Hold it

Hi, Do anyone know what's the max size of array (in awk) can be store before hit any memory issue. Regards

2. Shell Programming and Scripting

Size of an array in sh shell script

Is there a way to find out the size of an array in sh shell script? Thanks.

3. Solaris

command to find out total size of a specific file size (spread over the server)

hi all, in my server there are some specific application files which are spread through out the server... these are spread in folders..sub-folders..chid folders... please help me, how can i find the total size of these specific files in the server...

4. Programming

size of char array in c

i have to store a data more than 100000. i don't know the size of the data whether it may be 100000 or 1000000. so how can i define variable size; example char abc; but i don't know the size so how can i give array size?? in one sentence how can i give the array size dynamically so that i...

5. Programming

CHAR Array - stuffed with values - with more size than it holds

Hi All I am simulating a problem in the production where i faced a situation. Please find the following example program which i simulated. #include<stdio.h> #include<stdlib.h> #include<string.h> int main() { char str1;

6. Shell Programming and Scripting

The scripts not able to make the file to size 0, every times it go back to its original size

#!/bin/sh ########################################################################################################## #This script is being used for AOK application for cleaning up the .out files and zip it under logs directory. # IBM # Created #For pdocap201/pdoca202 .out files for AOK #1....

7. Shell Programming and Scripting

Use Awk and Array to get total size of files

Hello all, I need to do scripts total up the size in selected extension file for example motion.mov and segmentation.avi is in Label Media. For file info.doc and calc.xls in Label Document. I need output will be like this: count 1 Media,,2 GB count 2 Document,,4 GB My problem is,...

8. UNIX for Advanced & Expert Users

Physical disk IO size smaller than fragment block filesystem size ?

Hello, in one default UFS filesystem we have 8K block size (bsize) and 1K fragmentsize (fsize). At this scenary I thought all "FileSytem IO" will be 8K (or greater) but never smaller than the fragment size (1K). If a UFS fragment/blocksize is allwasy several ADJACENTS sectors on disk (in a ...

9. Programming

Php number array from max, min, step size mysql data

I want to create a form with data values in a dropdown list. The values in the dropdown list need to be generated on the fly from max, min and increment values contained in a mysql database. Hopefully this makes sense, I really have no idea where to start :confused: Thanks

10. Shell Programming and Scripting

Array size in C shell scripting

Hi, I would like to know how to define the size of the array in c shell scripting.

LEARN ABOUT PHP

posix_getrlimit

POSIX_GETRLIMIT(3)							 1							POSIX_GETRLIMIT(3)

posix_getrlimit - Return info about system resource limits

SYNOPSIS

       array posix_getrlimit (void  )

DESCRIPTION

       posix_getrlimit(3) returns an array of information about the current resource's soft and hard limits.

	Each  resource has an associated soft and hard limit. The soft limit is the value that the kernel enforces for the corresponding resource.
       The hard limit acts as a ceiling for the soft limit. An unprivileged process may only set its soft limit to a value  from  0  to  the  hard
       limit, and irreversibly lower its hard limit.

RETURN VALUES

	Returns an associative array of elements for each limit that is defined. Each limit has a soft and a hard limit.

       List of possible limits returned

       +-----------+---------------------------------------------------+
       |Limit name |						       |
       |	   |						       |
       |	   |		     Limit description		       |
       |	   |						       |
       +-----------+---------------------------------------------------+
       |   core    |						       |
       |	   |						       |
       |	   |  The  maximum  size of the core file. When 0, not |
       |	   | core files  are  created.	When  core  files  are |
       |	   | larger  than this size, they will be truncated at |
       |	   | this size. 				       |
       |	   |						       |
       | totalmem  |						       |
       |	   |						       |
       |	   |  The maximum size of the memory of  the  process, |
       |	   | in bytes.					       |
       |	   |						       |
       |virtualmem |						       |
       |	   |						       |
       |	   |  The  maximum  size of the virtual memory for the |
       |	   | process, in bytes. 			       |
       |	   |						       |
       |   data    |						       |
       |	   |						       |
       |	   |  The maximum size of the  data  segment  for  the |
       |	   | process, in bytes. 			       |
       |	   |						       |
       |  stack    |						       |
       |	   |						       |
       |	   |  The maximum size of the process stack, in bytes. |
       |	   |						       |
       |   rss	   |						       |
       |	   |						       |
       |	   |  The  maximum number of virtual pages resident in |
       |	   | RAM					       |
       |	   |						       |
       | maxproc   |						       |
       |	   |						       |
       |	   |  The maximum number of processes that can be cre- |
       |	   | ated for the real user ID of the calling process. |
       |	   |						       |
       | memlock   |						       |
       |	   |						       |
       |	   |  The  maximum  number of bytes of memory that may |
       |	   | be locked into RAM.			       |
       |	   |						       |
       |   cpu	   |						       |
       |	   |						       |
       |	   |  The amount of time the process is allowed to use |
       |	   | the CPU.					       |
       |	   |						       |
       | filesize  |						       |
       |	   |						       |
       |	   |  The  maximum  size  of  the data segment for the |
       |	   | process, in bytes. 			       |
       |	   |						       |
       |openfiles  |						       |
       |	   |						       |
       |	   |  One more than the maximum number	of  open  file |
       |	   | descriptors.				       |
       |	   |						       |
       +-----------+---------------------------------------------------+
EXAMPLES

       Example #1

	      Example use of posix_getrlimit(3)

	      <?php

	      $limits = posix_getrlimit();

	      print_r($limits);
	      ?>

	      The above example will output something similar to:

	      Array
	      (
		  [soft core] => 0
		  [hard core] => unlimited
		  [soft data] => unlimited
		  [hard data] => unlimited
		  [soft stack] => 8388608
		  [hard stack] => unlimited
		  [soft totalmem] => unlimited
		  [hard totalmem] => unlimited
		  [soft rss] => unlimited
		  [hard rss] => unlimited
		  [soft maxproc] => unlimited
		  [hard maxproc] => unlimited
		  [soft memlock] => unlimited
		  [hard memlock] => unlimited
		  [soft cpu] => unlimited
		  [hard cpu] => unlimited
		  [soft filesize] => unlimited
		  [hard filesize] => unlimited
		  [soft openfiles] => 1024
		  [hard openfiles] => 1024
	      )

NOTES

       Note

	       This is a not POSIX function, but is common on BSD and System V systems. If the system does not support this function, then it will
	      not be included at compile time. This may be checked with function_exists(3).

SEE ALSO

       man page GETRLIMIT(2).

PHP Documentation Group 													POSIX_GETRLIMIT(3)

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

MAX SIZE ARRAY Can Hold it

Discussion started by: epall

2. Shell Programming and Scripting

Size of an array in sh shell script

Discussion started by: trivektor

3. Solaris

command to find out total size of a specific file size (spread over the server)

Discussion started by: abhinov

4. Programming

size of char array in c

Discussion started by: phani_sree