explain_getrlimit(3)

NAME
explain_getrlimit - explain getrlimit(2) errors

SYNOPSIS
#include <libexplain/getrlimit.h>

const char *explain_getrlimit(int resource, struct rlimit *rlim);
const char *explain_errno_getrlimit(int errnum, int resource, struct rlimit *rlim);
void explain_message_getrlimit(char *message, int message_size, int resource, struct rlimit *rlim);
void explain_message_errno_getrlimit(char *message, int message_size, int errnum, int resource, struct rlimit *rlim);

DESCRIPTION
These functions may be used to obtain explanations for errors returned by the getrlimit(2) system call.

  explain_getrlimit
const char *explain_getrlimit(int resource, struct rlimit *rlim);

The explain_getrlimit function is used to obtain an explanation of an error returned by the getrlimit(2) system call. The least the message will contain is the value of strerror(errno), but usually it will do much better, and indicate the underlying cause in more detail.

The errno global variable will be used to obtain the error value to be decoded.

This function is intended to be used in a fashion similar to the following example:
    if (getrlimit(resource, rlim) < 0)
    {
        fprintf(stderr, "%s\n", explain_getrlimit(resource, rlim));
        exit(EXIT_FAILURE);
    }

The above code example is available pre-packaged as the explain_getrlimit_or_die(3) function.

resource
    The original resource, exactly as passed to the getrlimit(2) system call.

rlim
    The original rlim, exactly as passed to the getrlimit(2) system call.

Returns:
    The message explaining the error. This message buffer is shared by all libexplain functions which do not supply a buffer in their argument list. This will be overwritten by the next call to any libexplain function which shares this buffer, including other threads.

Note: This function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library.

  explain_errno_getrlimit
const char *explain_errno_getrlimit(int errnum, int resource, struct rlimit *rlim);

The explain_errno_getrlimit function is used to obtain an explanation of an error returned by the getrlimit(2) system call. The least the message will contain is the value of strerror(errnum), but usually it will do much better, and indicate the underlying cause in more detail.

This function is intended to be used in a fashion similar to the following example:
    if (getrlimit(resource, rlim) < 0)
    {
        int err = errno;
        fprintf(stderr, "%s\n", explain_errno_getrlimit(err, resource, rlim));
        exit(EXIT_FAILURE);
    }

The above code example is available pre-packaged as the explain_getrlimit_or_die(3) function.

errnum
    The error value to be decoded, usually obtained from the errno global variable just before this function is called. This is necessary if you need to call any code between the system call to be explained and this function, because many libc functions will alter the value of errno.

resource
    The original resource, exactly as passed to the getrlimit(2) system call.

rlim
    The original rlim, exactly as passed to the getrlimit(2) system call.

Returns:
    The message explaining the error. This message buffer is shared by all libexplain functions which do not supply a buffer in their argument list. This will be overwritten by the next call to any libexplain function which shares this buffer, including other threads.

Note: This function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library.

  explain_message_getrlimit
void explain_message_getrlimit(char *message, int message_size, int resource, struct rlimit *rlim);

The explain_message_getrlimit function may be used to obtain an explanation of an error returned by the getrlimit(2) system call. The least the message will contain is the value of strerror(errno), but usually it will do much better, and indicate the underlying cause in more detail.

The errno global variable will be used to obtain the error value to be decoded.

This function is intended to be used in a fashion similar to the following example:
    if (getrlimit(resource, rlim) < 0)
    {
        char message[3000];
        explain_message_getrlimit(message, sizeof(message), resource, rlim);
        fprintf(stderr, "%s\n", message);
        exit(EXIT_FAILURE);
    }

The above code example is available pre-packaged as the explain_getrlimit_or_die(3) function.

message
    The location in which to store the returned message. If a suitable message return buffer is supplied, this function is thread safe.

message_size
    The size in bytes of the location in which to store the returned message.

resource
    The original resource, exactly as passed to the getrlimit(2) system call.

rlim
    The original rlim, exactly as passed to the getrlimit(2) system call.

  explain_message_errno_getrlimit
void explain_message_errno_getrlimit(char *message, int message_size, int errnum, int resource, struct rlimit *rlim);

The explain_message_errno_getrlimit function may be used to obtain an explanation of an error returned by the getrlimit(2) system call. The least the message will contain is the value of strerror(errnum), but usually it will do much better, and indicate the underlying cause in more detail.

This function is intended to be used in a fashion similar to the following example:
    if (getrlimit(resource, rlim) < 0)
    {
        int err = errno;
        char message[3000];
        explain_message_errno_getrlimit(message, sizeof(message),
            err, resource, rlim);
        fprintf(stderr, "%s\n", message);
        exit(EXIT_FAILURE);
    }

The above code example is available pre-packaged as the explain_getrlimit_or_die(3) function.

message
    The location in which to store the returned message. If a suitable message return buffer is supplied, this function is thread safe.

message_size
    The size in bytes of the location in which to store the returned message.

errnum
    The error value to be decoded, usually obtained from the errno global variable just before this function is called. This is necessary if you need to call any code between the system call to be explained and this function, because many libc functions will alter the value of errno.

resource
    The original resource, exactly as passed to the getrlimit(2) system call.

rlim
    The original rlim, exactly as passed to the getrlimit(2) system call.

SEE ALSO

getrlimit(2)
    get resource limits

explain_getrlimit_or_die(3)
    get resource limits and report errors

COPYRIGHT
libexplain version
Copyright (C) 2008 Peter Miller