voldemort.store.readonly.io.jna
Class errno

java.lang.Object
  voldemort.store.readonly.io.jna.errno

public class errno
extends java.lang.Object

Constructor Summary

errno()

Method Summary

static int	errno() The header file defines the integer variable errno, which is set by system calls and some library functions in the event of an error to indicate what went wrong.
static int	perror(java.lang.String s) The routine perror() produces a message on the standard error output, describing the last error encountered during a call to a system or library function.
static java.lang.String	strerror()
static java.lang.String	strerror(int errnum) The strerror() function returns a string describing the error code passed in the argument errnum, possibly using the LC_MESSAGES part of the current locale to select the appropriate language.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

errno

public errno()

Method Detail

perror

public static int perror(java.lang.String s)

The routine perror() produces a message on the standard error output, describing the last error encountered during a call to a system or library function. First (if s is not NULL and *s is not a null byte ('\0')) the argument string s is printed, followed by a colon and a blank. Then the message and a new-line. To be of most use, the argument string should include the name of the function that incurred the error. The error number is taken from the external variable errno, which is set when errors occur but not cleared when non-erroneous calls are made. The global error list sys_errlist[] indexed by errno can be used to obtain the error message without the newline. The largest message number provided in the table is sys_nerr -1. Be careful when directly accessing this list because new error values may not have been added to sys_errlist[]. When a system call fails, it usually returns -1 and sets the variable errno to a value describing what went wrong. (These values can be found in .) Many library functions do likewise. The function perror() serves to translate this error code into human-readable form. Note that errno is undefined after a successful library call: this call may well change this variable, even though it succeeds, for example because it internally used some other library function that failed. Thus, if a failing call is not immediately followed by a call to perror(), the value of errno should be saved.

strerror

public static java.lang.String strerror(int errnum)

The strerror() function returns a string describing the error code passed in the argument errnum, possibly using the LC_MESSAGES part of the current locale to select the appropriate language. This string must not be modified by the application, but may be modified by a subsequent call to perror() or strerror(). No library function will modify this string. The strerror_r() function is similar to strerror(), but is thread safe. This function is available in two versions: an XSI-compliant version specified in POSIX.1-2001, and a GNU-specific version (available since glibc 2.0). If _XOPEN_SOURCE is defined with the value 600, then the XSI-compliant version is provided, otherwise the GNU-specific version is provided. The XSI-compliant strerror_r() is preferred for portable applications. It returns the error string in the user-supplied buffer buf of length buflen. The GNU-specific strerror_r() returns a pointer to a string containing the error message. This may be either a pointer to a string that the function stores in buf, or a pointer to some (immutable) static string (in which case buf is unused). If the function stores a string in buf, then at most buflen bytes are stored (the string may be truncated if buflen is too small) and the string always includes a terminating null byte.

strerror

public static java.lang.String strerror()

errno

public static int errno()

The header file defines the integer variable errno, which is set by system calls and some library functions in the event of an error to indicate what went wrong. Its value is significant only when the call returned an error (usually -1), and a function that does succeed is allowed to change errno. Sometimes, when -1 is also a valid successful return value one has to zero errno before the call in order to detect possible errors. errno is defined by the ISO C standard to be a modifiable lvalue of type int, and must not be explicitly declared; errno may be a macro. errno is thread-local; setting it in one thread does not affect its value in any other thread. Valid error numbers are all non-zero; errno is never set to zero by any library function. All the error names specified by POSIX.1 must have distinct values, with the exception of EAGAIN and EWOULDBLOCK, which may be the same. Below is a list of the symbolic error names that are defined on Linux. Some of these are marked POSIX.1, indicating that the name is defined by POSIX.1-2001, or C99, indicating that the name is defined by C99.