NAME
dlerror - get diagnostic information
SYNOPSIS
#include <dlfcn.h>
char *dlerror(void);
DESCRIPTION
The dlerror() function shall return a null-terminated character string
(with no trailing <newline>) that describes the last error that
occurred during dynamic linking processing. If no dynamic linking
errors have occurred since the last invocation of dlerror(), dlerror()
shall return NULL. Thus, invoking dlerror() a second time, immediately
following a prior invocation, shall result in NULL being returned.
The dlerror() function need not be reentrant. A function that is not
required to be reentrant is not required to be thread-safe.
RETURN VALUE
If successful, dlerror() shall return a null-terminated character
string; otherwise, NULL shall be returned.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
The following example prints out the last dynamic linking error:
...
#include <dlfcn.h>
char *errstr;
errstr = dlerror();
if (errstr != NULL)
printf ("A dynamic linking error occurred: (%s)\n", errstr);
...
APPLICATION USAGE
The messages returned by dlerror() may reside in a static buffer that
is overwritten on each call to dlerror(). Application code should not
write to this buffer. Programs wishing to preserve an error message
should make their own copies of that message. Depending on the
application environment with respect to asynchronous execution events,
such as signals or other asynchronous computation sharing the address
space, conforming applications should use a critical section to
retrieve the error pointer and buffer.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
dlclose() , dlopen() , dlsym() , the Base Definitions volume of
IEEE Std 1003.1-2001, <dlfcn.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .