libexplain/getrlimit.h File Reference

explain getrlimit(2) errors More...

#include <libexplain/gcc_attributes.h>

Go to the source code of this file.

Functions
void	explain_getrlimit_or_die (int resource, struct rlimit *rlim)
int	explain_getrlimit_on_error (int resource, struct rlimit *rlim) LIBEXPLAIN_WARN_UNUSED_RESULT
const char *	explain_getrlimit (int resource, struct rlimit *rlim) LIBEXPLAIN_WARN_UNUSED_RESULT
const char *	explain_errno_getrlimit (int errnum, int resource, struct rlimit *rlim) LIBEXPLAIN_WARN_UNUSED_RESULT
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)

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Detailed Description

explain getrlimit(2) errors

Definition in file getrlimit.h.

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Function Documentation

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 function.

Parameters:

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.

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 function.

Parameters:

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.

int explain_getrlimit_on_error	(	int	resource,
		struct rlimit *	rlim
	)

The explain_getrlimit_on_error function is used to call the getrlimit(2) system call. On failure an explanation will be printed to stderr, obtained from the explain_getrlimit(3) function.

This function is intended to be used in a fashion similar to the following example:

 if (explain_getrlimit_on_error(resource, rlim) < 0)
 {
     ...cope with error
     ...no need to print error message
 }

Parameters:

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

Returns:

The value returned by the wrapped getrlimit(2) system call.

void explain_getrlimit_or_die	(	int	resource,
		struct rlimit *	rlim
	)

The explain_getrlimit_or_die function is used to call the getrlimit(2) system call. On failure an explanation will be printed to stderr, obtained from the explain_getrlimit(3) function, and then the process terminates by calling exit(EXIT_FAILURE).

This function is intended to be used in a fashion similar to the following example:

 explain_getrlimit_or_die(resource, rlim);

Parameters:

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

Returns:

This function only returns on success. On failure, prints an explanation and exits, it does not return.

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

The explain_message_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;
     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 function.

Parameters:

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.

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

The explain_message_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.

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 function.

Parameters:

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.