getrlimit(), getrlimit64()

Arguments:

resource

The resource whose limit you want to get; one of the following:

• RLIMIT_AS
• RLIMIT_CHANNELS_NP
• RLIMIT_CORE
• RLIMIT_CPU
• RLIMIT_DATA
• RLIMIT_FREEMEM
• RLIMIT_FSIZE
• RLIMIT_MQUEUE_NUM_NP
• RLIMIT_MQUEUE_SIZE_NP
• RLIMIT_NOCONN_NP
• RLIMIT_NOFILE
• RLIMIT_NPROC
• RLIMIT_NTHR
• RLIMIT_OFILE
• RLIMIT_RSS
• RLIMIT_SHM_HANDLES_NP
• RLIMIT_SIGEVENT_NP
• RLIMIT_STACK
• RLIMIT_TIMERS_NP
• RLIMIT_VMEM

For descriptions and the actions taken when the current limit is exceeded, see prlimit().

rlp

A pointer to an rlimit or rlimit64 structure where the function can store the limit on the resource. The rlimit and rlimit64 structures include at least the following members:

rlim_t rlim_cur; /* current (soft) limit */
rlim_t rlim_max; /* hard limit */

The rlim_t type is an arithmetic data type to which you can cast objects of type int, size_t, and off_t without loss of information.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The getrlimit() and getrlimit64() functions get the limits on the consumption of various system resources by a process and each process it creates.

Each call to getrlimit() identifies a specific resource to be operated upon as well as a resource limit. A resource limit is a pair of values: one specifying the current (soft) limit, the other a maximum (hard) limit. The call to getrlimit() in turn calls prlimit() with the new_rlp argument set to NULL.

For information on how to change limit values, refer to the description of setrlimit() or prlimit().

Returns:

0

Success.

-1

An error occurred (errno is set).

Errors:

EFAULT

The rlp argument points to an illegal address.

EINVAL

An invalid resource was specified.

Examples:

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

int main( void )
{
    struct rlimit curr_limits;
    
    if (getrlimit (RLIMIT_NPROC, &curr_limits) == -1) {
        perror ("The call to getrlimit() failed.");
        return EXIT_FAILURE;
    } else {
        printf ("The current maximum number of processes is %d.\n",
               (int) curr_limits.rlim_cur);
        printf ("The hard limit on the number of processes is %d.\n",
               (int) curr_limits.rlim_max);
    }
        return EXIT_SUCCESS;
}

Classification:

getrlimit() is POSIX 1003.1; getrlimit64() is Large-file support