Re: [libvirt] [PATCH 5/5] Add "syslog/json" log output format.

This is independent from the rest of the series, sending it anyway for consideration; this makes the metadata available to users on non-systemd platforms. I believe the technical objections (primarily async-signal-safety) have been resolved; the question of whether the project wants to support this or not is still open, of course. Add a "syslog/json" output format, which uses a JSON representation (as specified in Lumberjack project, and planned for the CEE standard) to format individual components, making the result easy to parse without writing custom code or using unreliable regexps. Example message (line-wrapped for readability, the actual output is a single line): Oct 17 16:29:56 kulicka libvirt: @cee: {"msg":"Domain not found", "LIBVIRT_SOURCE":"error","priority":"err", "CODE_FILE":"../../src/test/test_driver.c","CODE_LINE":1405, "CODE_FUNC":"testLookupDomainByName", "timestamp":"2012-10-17 14:29:56.683+0000","DOMAIN":12,"CODE":42, "STR1":"Domain not found","STR2":""} None of the existing log output formats (e.g. "syslog" or "file") is affected. Async-signal-safety is preserved by a) providing a custom allocation function to yajl, and b) using a custom print function. Both use memory allocated within the stack frame.