DLERROR(3P) POSIX Programmer's Manual DLERROR(3P)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.
NAMEdlerror — get diagnostic information
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.
It is implementation-defined whether or not the dlerror() function is
thread-safe. A thread-safe implementation shall return only errors that
occur on the current thread.
If successful, dlerror() shall return a null-terminated character
string; otherwise, NULL shall be returned.
The application shall not modify the string returned. The returned
pointer might be invalidated or the string content might be overwritten
by a subsequent call to dlerror() in the same thread (if dlerror() is
thread-safe) or in any thread (if dlerror() is not thread-safe).
No errors are defined.
The following sections are informative.
The following example prints out the last dynamic linking error:
errstr = dlerror();
if (errstr != NULL)
printf ("A dynamic linking error occurred: (%s)\n", errstr);
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 criti‐
cal section to retrieve the error pointer and buffer.
SEE ALSOdlclose(), dlopen(), dlsym()
The Base Definitions volume of POSIX.1‐2008, <dlfcn.h>
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .
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IEEE/The Open Group 2013 DLERROR(3P)