This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       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.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group  Base
       Specifications  Issue  7, 2018 Edition, Copyright (C) 2018 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 .

       Any  typographical  or formatting errors that appear in this page are most likely to have been introduced
       during  the  conversion  of  the  source  files  to  man  page  format.  To  report  such   errors,   see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                       DLERROR(3POSIX)

       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.

       No errors are defined.

       Thefollowingsectionsareinformative.

       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);
           ...

       None.

       dlerror — get diagnostic information

       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.

       None.

       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). The returned pointer might also be
       invalidated if the calling thread is terminated.

dlclose(), dlopen(), dlsym()

       The Base Definitions volume of POSIX.1‐2017, <dlfcn.h>

       #include <dlfcn.h>

       char *dlerror(void);