Re: [systemd-devel] Unbuffered stderr for my systemd service?
On Tue, Jul 16, 2013 at 5:30 AM, WANG Chao chaow...@redhat.com wrote: (Humm, please do not use -- on a single line in the middle of an email, that's indication for many MUAs that this is where the signature starts, and they chop this off when replying...) Sorry about --, never thought that would be an issue. Thanks for telling! It would only happen on _really_ broken mail programs, because the convention includes a trailing space character which you didn't add. The delimiter line is defined as -- . http://tools.ietf.org/html/rfc3676#section-4.3 Kay ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Unbuffered stderr for my systemd service?
On Tue, Jul 16, 2013 at 5:30 AM, WANG Chao chaow...@redhat.com wrote: On 07/15/13 at 10:46pm, Lennart Poettering wrote: On Mon, 15.07.13 17:56, WANG Chao (chaow...@redhat.com) wrote: I have a service (a script) running under systemd and need its stderr to be output'd immediately, not line buffered. I tried serveral ways but didn't work out. I hope to get some feedback here :) This is not supported. Logging doesn't deal in individual characters, really, but in log lines. Syslog doesn't do that, and neither does the Journal. And we will never support that, as allowing this would require us to always store the context a character was printed in so that lines could later be reassembled. But we cannot really do that. So, I fear I have to tell you that this is not supported and never will... I understand that. Record the context of a character is printed would never be a good idea. But still, I feel pity about line buffered stderr stream in Journal :( It is the right thing to buffer just buffer them to full lines. For the kernel counterpart, we added unbuffered console magic to the kernel. It is really nasty and broken hack and really makes not much sense in th eend. The code does work in the most common case, but just does stupid things as soon as things start to compete about the log. http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=084681d14e429cb6192262ac7437f00e2c02f26a http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=eab072609e11a357181806ab5a5c309ef6eb76f5 Pretending to support pushing animations through a log system is a pretty bad idea and relies on technical promises nobody can really hold without inventing something that isn't logging anymore. But we have that already, it's the console. :) Kay ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Unbuffered stderr for my systemd service?
On 07/16/13 at 01:39pm, Kay Sievers wrote: On Tue, Jul 16, 2013 at 5:30 AM, WANG Chao chaow...@redhat.com wrote: (Humm, please do not use -- on a single line in the middle of an email, that's indication for many MUAs that this is where the signature starts, and they chop this off when replying...) Sorry about --, never thought that would be an issue. Thanks for telling! It would only happen on _really_ broken mail programs, because the convention includes a trailing space character which you didn't add. The delimiter line is defined as -- . http://tools.ietf.org/html/rfc3676#section-4.3 Great to know! I'm curious about what mail client Lennart has been using. Surely he deserves a better one :P WANG Chao ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Unbuffered stderr for my systemd service?
On 07/16/13 at 02:00pm, Kay Sievers wrote: On Tue, Jul 16, 2013 at 5:30 AM, WANG Chao chaow...@redhat.com wrote: On 07/15/13 at 10:46pm, Lennart Poettering wrote: On Mon, 15.07.13 17:56, WANG Chao (chaow...@redhat.com) wrote: I have a service (a script) running under systemd and need its stderr to be output'd immediately, not line buffered. I tried serveral ways but didn't work out. I hope to get some feedback here :) This is not supported. Logging doesn't deal in individual characters, really, but in log lines. Syslog doesn't do that, and neither does the Journal. And we will never support that, as allowing this would require us to always store the context a character was printed in so that lines could later be reassembled. But we cannot really do that. So, I fear I have to tell you that this is not supported and never will... I understand that. Record the context of a character is printed would never be a good idea. But still, I feel pity about line buffered stderr stream in Journal :( It is the right thing to buffer just buffer them to full lines. Yes. Or buffer wouldn't be called buffer. For the kernel counterpart, we added unbuffered console magic to the kernel. It is really nasty and broken hack and really makes not much sense in th eend. The code does work in the most common case, but just does stupid things as soon as things start to compete about the log. http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=084681d14e429cb6192262ac7437f00e2c02f26a http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=eab072609e11a357181806ab5a5c309ef6eb76f5 Pretending to support pushing animations through a log system is a pretty bad idea and relies on technical promises nobody can really hold without inventing something that isn't logging anymore. But we have that already, it's the console. :) I couldn't agree more. Log system can't really record animations in a common way. So in my case, console is right thing to use. Thanks for your information here. Have a good day! WANG Chao ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Unbuffered stderr for my systemd service?
On Mon, 15.07.13 17:56, WANG Chao (chaow...@redhat.com) wrote: Hi, I have a service (a script) running under systemd and need its stderr to be output'd immediately, not line buffered. I tried serveral ways but didn't work out. I hope to get some feedback here :) This is not supported. Logging doesn't deal in individual characters, really, but in log lines. Syslog doesn't do that, and neither does the Journal. And we will never support that, as allowing this would require us to always store the context a character was printed in so that lines could later be reassembled. But we cannot really do that. So, I fear I have to tell you that this is not supported and never will... Here's my foobar.service: (Humm, please do not use -- on a single line in the middle of an email, that's indication for many MUAs that this is where the signature starts, and they chop this off when replying...) Lennart -- Lennart Poettering - Red Hat, Inc. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Unbuffered stderr for my systemd service?
On Mon, 15.07.13 10:32, Vivek Goyal (vgo...@redhat.com) wrote: CCing Lennart. This is important functionality for us. makeudmpfile utility (utility which filters kernel crash dump and shows the progress bar), run in kdump kernel. For large machines it displays the progress bar in kernel. Right now all the code runs from initramfs in the context of a service and we don't get progress messages. Just we get a 100% message at the end. Right now we bypassed journal by sending everything to /dev/console but it is a generic question that any serivce displaying some kind of progress bar, how is it handled with current journal mechanism. if you want to do fancier output then do facnier ouput directly on the console, but do not pumpt this through a log system, that's really not what it is for... Lennart -- Lennart Poettering - Red Hat, Inc. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Unbuffered stderr for my systemd service?
On 07/15/13 at 10:46pm, Lennart Poettering wrote: On Mon, 15.07.13 17:56, WANG Chao (chaow...@redhat.com) wrote: Hi, I have a service (a script) running under systemd and need its stderr to be output'd immediately, not line buffered. I tried serveral ways but didn't work out. I hope to get some feedback here :) This is not supported. Logging doesn't deal in individual characters, really, but in log lines. Syslog doesn't do that, and neither does the Journal. And we will never support that, as allowing this would require us to always store the context a character was printed in so that lines could later be reassembled. But we cannot really do that. So, I fear I have to tell you that this is not supported and never will... I understand that. Record the context of a character is printed would never be a good idea. But still, I feel pity about line buffered stderr stream in Journal :( Here's my foobar.service: (Humm, please do not use -- on a single line in the middle of an email, that's indication for many MUAs that this is where the signature starts, and they chop this off when replying...) Sorry about --, never thought that would be an issue. Thanks for telling! WANG Chao ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
