DLERROR(P) POSIX Programmer s Manual DLERROR(P)

PROLOG This manual page is part of the POSIX Programmer s Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

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: (%sn", 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 applica- tion 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 .

IEEE/The Open Group 2003 DLERROR(P)