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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 .