Linked by Eugenia Loli-Queru on Fri 8th Sep 2006 04:08 UTC
Proper error detection and recovery is often ignored by UNIX developers. The lack of exceptions from the C language and the rudimentary error mechanisms from the standard C library certainly contribute to this. This article familiarizes you with the UNIX standard error reporting mechanism, the errno global variable. You'll also learn about a couple of associated global variables ( sys_nerr and sys_errlist) and the standard functions that help you report errors to the user and (hopefully) encourages you to report and handle errors in a user-friendly way.
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Member since:2006-07-27
Member since:
2005-07-06
... Yeah, sure, exception is much more powerful.
If you need fine grained error recovery, instead of doing:
int err;
..
if ((err = command(...)) < 0) {
/* Fine grained error recovery. */
err = errno;
goto out;
}
You do:
int previous_err = 0;
int err = 0;
...
if (!previous_err) {
try {
command(...);
}
catch (...) {
// Fine gained error recovery.
...
// No goto. We don't do such things in
// CPP. Lets us just do if previous_err
// 128 times till the end of the function.
previous_err = err;
}
}
<SARCASM>
Yep, indeed C++ exception is much better at fine-grained error recovery then C
is.
Thank God kernels and OS libraries are still written in C!
</SARCASM>
- Gilboa
* Sorry about that... I'm just faced, on a daily basis, by herd of C++ programmers who throw C++ on each stupid error, failing to do any type of error recovery and leaving all the clean up to the CPP/C libraries/drivers/etc.
Edited 2006-09-08 21:47