Rob Dixon wrote: > Sudarshan Raghavan wrote: > > > > Both STDERR and STDOUT are line buffered, when a "\n" is seen > > the contents of the buffer is flushed. Turning on autoflush is superfluous > > in this case. Try this instead :-) > > > > #!/usr/local/bin/perl > > use strict; > > use warnings; > > > > select (STDERR); > > $| = 1; > > print STDOUT "STDOUT"; > > print STDERR "STDERR"; > > As I pointed out, precisely how the streams are handled is > platform-dependent. On my Win2KPro system this > > print STDERR "STDERR\n"; > print STDOUT "STDOUT\n"; > > outputs this > > STDOUT > STDERR > > so they are clearly not line-buffered. Whether it is generally > true that they are on *nix systems I cannot say. > > Cheers, > > Rob
Hi Rob, I think you have it reversed. Had me going for awhile, too. If you retest, you may see what I mean. Think about it a little--when you run a program, do you expect everything to run, and then report your errors? Vicee-versetz, nay? So far this only works for me on the 5.8 installation, but: On 5.8: #!/usr/bin/perl use strict; print STDOUT "STDOUT"; print STDERR "STDERR"; print "\n"; $| = 1; print STDOUT "STDOUT"; print STDERR "STDERR"; Yields: Hi There,podner E:\d_drive\perlStuff>flush.pl STDERRSTDOUT STDOUTSTDERR But on Perl 5.61, the same code yields: STDOUTSTDERR STDOUTSTDERR One possible difference--on the box running 5.61, I have only two other application windows open, and the script is the only open window in PFE. The PC running 5.8 has 19 applications open, including two browsers, each with long session histories, and eleven files open in PFE. It could be that without autoflush explicitly called, the system flushes at low-priority opportunity. Anyway, this is my take on the question: 1) When there is a difference, STDERR would take precedence, since it is more critical to report operating errors than to return [possibly erroneous] output. 2) The inversion behavior you describe without autoflush can not be repeated dependably across systems. 3) The sequence of output will dependably track the sequence of input with autoflush turned on. Joseph -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
