DLERROR(3P)

💖 DLERROR(3P) — POSIX Programmer's Manual 💖

okay bestie, so this one's from the POSIX Programmer's Manual — that's DLERROR(3P), get into it ✨

🌸 PROLOG 🌸

okay so first things first, this manual page is part of the POSIX Programmer's Manual. and like, heads up: the Linux implementation of this interface may differ, so pls consult the corresponding Linux manual page for the deets on Linux behavior. or honestly? the interface might not even be implemented on Linux at all 💀. vibe check accordingly.

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✨ NAME ✨

dlerror — get diagnostic information 🩺

🦋 SYNOPSIS 🦋

#include <dlfcn.h>

char *dlerror(void);

💅 DESCRIPTION 💅

so 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. it's giving error gossip, and it's giving it fresh 🫶

but here's the thing: if no dynamic linking errors have occurred since the last invocation of dlerror(), then dlerror() shall return NULL. so like, invoking dlerror() a second time, immediately following a prior invocation, shall result in NULL being returned. it's a one-time tea spill, bestie — read it once or it's gone ☕

and ngl, 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 crossover drama, periodt.

🔥 RETURN VALUE 🔥

if successful, dlerror() shall return a null-terminated character string; otherwise, NULL shall be returned.

🚨 okay MAJOR rule: the application shall not modify the string returned. do not touch. hands off. it's not yours.

also, 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). and the returned pointer might also be invalidated if the calling thread is terminated. so basically that pointer is on borrowed time, lowkey 💀 copy what you need.

🙈 ERRORS 🙈

No errors are defined. iconic honestly.

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);
...

look at her go 🎀

🌈 APPLICATION USAGE 🌈

depending on the application environment with respect to asynchronous execution events — like signals, or other asynchronous computation sharing the address space — conforming applications should use a critical section to retrieve the error pointer and buffer. yes bestie, lock it down before you read it 🔒

🧚 RATIONALE 🧚

None. (she said nothing and she meant it 💅)

🌸 FUTURE DIRECTIONS 🌸

None. (the future is looking very chill, no cap ✨)

🫶 SEE ALSO 🫶

• dlclose()
• dlopen()
• dlsym()
• The Base Definitions volume of POSIX.1‐2017, <dlfcn.h>

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👑 COPYRIGHT 👑

okay so legal bit, but make it cute:

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 .

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and that's the whole page bestie — DLERROR(3P) from IEEE/The Open Group, 2017. mwah. go read your error strings, stay hydrated, and remember: dlerror() twice in a row gives you NULL, so screenshot the first one 💖✨🎀