Name

ulimit − get and set user limits

Syntax

long ulimit (cmd, newlimit)
int cmd;
long newlimit;

Description

This function provides control over process limits.  An explanation of the cmd values follow. 

ValueExplanation

1Get the process’s file size limit.  The limit is in units of 512-byte blocks and is inherited by child processes.  Files of any size can be read. 

2Set the process’s file size limit to the value of newlimit.  Any process can decrease this limit, but only a process with an effective user ID of superuser can increase the limit.  The ulimit system call fails and the limit remains unchanged, if a process with an effective user ID other than superuser attempts to increase its file size limit.

3Get the maximum possible break value.  For further information, see brk(.).

Return Values

Upon successful completion, a nonnegative value is returned.  Otherwise, a value of −1 is returned, and errno is set to indicate the error. 

Diagnostics

[EINVAL] Bad value for cmd. 

[EPERM] The effective user ID of the calling process is not superuser. 

See Also

brk(2), write(2)