From 13317a22e5cf8f7c458616a971e60e84255bc364 Mon Sep 17 00:00:00 2001 From: mulkieran Date: Tue, 19 Jul 2016 23:15:22 -0400 Subject: man: revise entry about specifying a file path (#3739) * Specifying a device node has an effect much larger than a simple shortcut for a field/value match, so the original sentence is no longer a good way to start the paragraph. * Specifying a device node causes matches to be generated for all ancestor devices of the device specified, not just its parents. * Indicates that the path must be absolute, but that it may be a link. * Eliminates a few typos. --- man/journalctl.xml | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) diff --git a/man/journalctl.xml b/man/journalctl.xml index 29239c6315..e77621d7b3 100644 --- a/man/journalctl.xml +++ b/man/journalctl.xml @@ -87,18 +87,26 @@ causes all matches before and after to be combined in a disjunction (i.e. logical OR). - As shortcuts for a few types of field/value matches, file - paths may be specified. If a file path refers to an executable - file, this is equivalent to an _EXE= match - for the canonicalized binary path. Similarly, if a path refers - to a device node then match is added for the kernel name of the - device (_KERNEL_DEVICE=). Also, matches for the - kernel names of all the parent devices are added automatically. - Device node paths are not stable across reboots, therefore match - for the current boot id (_BOOT_ID=) is - always added as well. Note that only the log entries for - the existing device nodes maybe queried by providing path to - the device node. + It is also possible to filter the entries by specifying an + absolute file path as an argument. The file path may be a file or + a symbolic link and the file must exist at the time of the query. If a + file path refers to an executable binary, an _EXE= + match for the canonicalized binary path is added to the query. If a + file path refers to an executable script, a _COMM= + match for the script name is added to the query. If a file path + refers to a device node, _KERNEL_DEVICE= matches for + the kernel name of the device and for each of its ancestor devices is + added to the query. Symbolic links are dereferenced, kernel names are + synthesized, and parent devices are identified from the environment at + the time of the query. In general, a device node is the best proxy for + an actual device, as log entries do not usually contain fields that + identify an actual device. For the resulting log entries to be correct + for the actual device, the relevant parts of the environment at the time + the entry was logged, in particular the actual device corresponding to + the device node, must have been the same as those at the time of the + query. Because device nodes generally change their corresponding devices + across reboots, specifying a device node path causes the resulting + entries to be restricted to those from the current boot. Additional constraints may be added using options , , etc., to -- cgit v1.2.3-54-g00ecf