Get disk space

I just read today on sun.com that checking disk space in java will be platform independent in the java.io.File class before 2007, add a few years until it is integrated in Oracle. But I cannot wait that long, so I decided to write my own code with “df” on my AIX box.

Ok, let’s do java. The horrible regexp there is parsing df.

create or replace and compile
java source named “Df”
as
import java.io.*;
public class Df
{
public static int getFree(String args)
{
return Integer.parseInt(df(args).replaceAll(“[^0-9]*[ ]*[1 ][0-9 ][0-9][0-9][%-][^ ]* [^ ]*[ ]*[^ ]*[ ]*[^ ]*[ ]*[^ ]*[ ]*[^ ]*[ ]*[^ ]*[ ]*[^ ]*[ ]*[^ ]*”,””).trim());
}
public static String getFS(String args)
{
return df(args).replaceAll(“[^ ]*[ ]*[^ ]*[ ]*[^ ]*[ ]*[1 ][0-9 ][0-9][0-9][%-][^ ]* [^ ]*[ ]*[^ ]*[ ]*[^ ]*[ ]*[^ ]*[ ]*[^ ]*[ ]*[^ /]*”,””).trim();
}
public static String df(String args)
{
String rc = “”;
try
{
Process p = Runtime.getRuntime().exec(“/bin/df -kt “+args);
int bufSize = 4096;
BufferedInputStream bis = new BufferedInputStream(p.getInputStream(), bufSize);
int len;
byte buffer[] = new byte[bufSize];
while ((len = bis.read(buffer, 0, bufSize)) != 1)
rc += new String(buffer, 0, len-1);
p.waitFor();
}
catch (Exception e)
{
e.printStackTrace();
}
finally
{
return rc;
}
}
}
/

Now I create two functions

create or replace
function getFree( p_cmd in varchar2) return number
as
language java
name ‘Df.getFree(java.lang.String) return int';
/

create or replace
function getFS( p_cmd in varchar2) return varchar2
as
language java
name ‘Df.getFS(java.lang.String) return String';
/

Ok, let’s see if my files can autoextend

select file_name, BYTES/1024 K, INCREMENT_BY*BYTES/BLOCKS/1024 INC, MAXBYTES/1024 MAXKBYTES, GETFREE(FILE_NAME) FREE, GETFS(FILE_NAME) FS
from dba_data_files

FILE_NAME K INC MAXKBYTES FREE FS
—————————————— ———- ———- ———- ———- ————–
/dbms/oracle/LSC68/data/system01LSC68.dbf 332800 25600 2097152 3579528 /dev/lsc68
/dbms/oracle/LSC68/data/undo01LSC68.dbf 184320 2048 204800 3579528 /dev/lsc68
/dbms/oracle/LSC68/data/sysaux01LSC68.dbf 228352 25600 2097152 3579528 /dev/lsc68
/dbms/oracle/LSC68/data/users01LSC68.dbf 24576 2048 2097152 3579528 /dev/lsc68
/dbms/oracle/LSC68/data/sysaud01_LSC68.dbf 4096 5120 204800 3579528 /dev/lsc68
/app/oracle/product/10.1.0.3/dbs/t.dbf 1024 0 0 851784 /dev/ora10103

Sounds good! plenty of free space to let the files grow!

2 thoughts on “Get disk space”

  1. Hi,
    if u just need the db freespaces, simply query that by sql

    SELECT sum(bytes)/1024/1024 as MB_Free,tablespace_name FROM dba_free_space WHERE tablespace_name ‘TEMP’ GROUP BY tablespace_name

    thats all

  2. this is the free space in the tablespace and not on the filesystem

    note that sum(bytes) is never 0, so if you have a full tablespace, you will get no row in dba_free_space

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