QUOTACTL(2)		   Linux Programmers Manual		  QUOTACTL(2)



NAME
       quotactl - manipulate disk quota

SYNOPSIS
       #include 
       #include 

       int quotactl(int cmd, const char *special, int id, caddr_t addr);

DESCRIPTION
       The  quota system defines for each user and/or group a soft limit and a
       hard limit bounding the amount of disk space that  can  be  used  on  a
       given  file  system.  The hard limit cannot be crossed.	The soft limit
       can be crossed, but warnings will ensue.  Moreover, the user cannot  be
       above  the  soft  limit	for more than one week (by default) at a time:
       after this week the soft limit counts as hard limit.

       The quotactl() system call manipulates these quota.  Its first argument
       is  of  the  form  QCMD(subcmd,type)  where  type is either USRQUOTA or
       GRPQUOTA (for user quota and group quota, respectively), and subcmd  is
       described below.

       The  second  argument  special  is the block special device these quota
       apply to.  It must be mounted.

       The third argument id is the user or group  ID  these  quota  apply  to
       (when relevant).

       The  fourth argument addr is the address of a data structure, depending
       on the command.

       The subcmd is one of

       Q_QUOTAON  Enable quota.  The addr argument is the pathname of the file
		  containing the quota for the file system.

       Q_QUOTAOFF Disable quota.

       Q_GETQUOTA Get  limits and current usage of disk space.	The addr argu
		  ment	is  a  pointer	to  a  dqblk  structure  (defined   in
		  ).

       Q_SETQUOTA Set limits and current usage; addr is as before.

       Q_SETQLIM  Set limits; addr is as before.

       Q_SETUSE   Set usage.

       Q_SYNC	  Sync disk copy of a file systems quota.

       Q_GETSTATS Get collected stats.

RETURN VALUE
       On  success, quotactl() returns 0.  On error, -1 is returned, and errno
       is set appropriately.

ERRORS
       EACCES	The quota file is not an ordinary file.

       EBUSY	Q_QUOTAON was asked, but quotas were enabled already.

       EFAULT	Bad addr value.

       EINVAL	type is not a known quota type.   Or,  special	could  not  be
		found.

       EIO	Cannot read or write the quota file.

       EMFILE	Too many open files: cannot open quota file.

       ENODEV	special cannot be found in the mount table.

       ENOPKG	The kernel was compiled without quota support.

       ENOTBLK	special is not a block special device.

       EPERM	The process was not root (for the file system), and Q_GETQUOTA
		was asked for another id than that of the process  itself,  or
		anything other than Q_GETSTATS or Q_SYNC was asked.

       ESRCH	Q_GETQUOTA  or	Q_SETQUOTA  or Q_SETUSE or Q_SETQLIM was asked
		for a file system that didnt have quota enabled.

CONFORMING TO
       BSD.

SEE ALSO
       quota(1), getrlimit(2), setrlimit(2),  ulimit(3),  quotacheck(8),  quo
       taon(8)

COLOPHON
       This  page  is  part of release 3.05 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.



Linux				  2007-06-01			   QUOTACTL(2)