:> The are dozens of libc routines which call malloc internally and return :> allocated storage. strdup(), opendir(), fopen(), setvbuf(), asprintf(), :> and so forth. Dozens. And while we might check some of these for NULL, :> we don't check them all, and the ones we do check we tend to conclude :> a failure other then a memory failure. We would assume that the directory :> or file does not exist, for example. How many programmers check errno :> after such a failure? Very few. How many programmers bother to even :> *clear* errno before making these calls (since some system calls do not : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ :We're not supposed to have to clear errno unless we have to explicitly :test if it has changed. We're not supposed to clear it before any system :call which could possibly fail and set errno. : :> set errno if it already non-zero). Virtually nobody. : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ :Erm... WTF?!?! If so, why the HELL are we doing that?!?
No, wait, I got that wrong I think. Oh yah, I remember now. Hmm. How odd. I came across a case where read() could return -1 and not set errno properly if errno was already set, but a perusal of the kernel code seems to indicate that this can't happen. Very weird. -Matt Matthew Dillon <dil...@backplane.com> To Unsubscribe: send mail to majord...@freebsd.org with "unsubscribe freebsd-hackers" in the body of the message