I thought I would check errno after a long string of printf calls ...
I thought I'd check errno after a long string of printf calls, to see if any of them had failed:
errno = 0;
if(errno != 0)
fprintf(stderr, "printf failed: %s\n", strerror(errno));
Why is it printing something strange like ``printf failed: Not a typewriter'' when I redirect the output to a file?
Many implementations of the stdio package adjust their behavior slightly if stdout is a terminal. To make the determination, these implementations perform some operation which happens to fail (with ENOTTY) if stdout is not a terminal. Although the output operation goes on to complete successfully, errno still contains ENOTTY. This behavior can be mildly confusing, but it is not strictly incorrect, because it is only meaningful for a program to inspect the contents of errno after an error has been reported. (More precisely, errno is only meaningful after a library function that sets errno on error has returned an error code.)
In general, it's best to detect errors by checking a function's return value. To check for any accumulated error after a long string of stdio calls, you can use ferror.
2015-10-14, 895👍, 0💬
How can I enable session tracking for JSP pages if the browser has disabled cookies? We know that se...
How To Merge Cells in a Column? - XHTML 1.0 Tutorials - Understanding Tables and Table Cells If you ...
The object that contains all the properties and methods for every ASP.NET page, that is built is .. ...
Once I have developed the COM wrapper do I have to still register the COM in registry? Yes.
Can include files be nested? The answer is yes. Include files can be nested any number of times. As ...