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@@ -0,0 +1,67 @@
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+# System Log
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+
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+## Viewing the System Log from LuCi
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+
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+Select the `Status >> System Log` menu entry.
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+
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+![alt text](images/librecmc-selecting-system-log.png "Selecting the
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+ System Log page in LuCi")
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+
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+![alt text](images/librecmc-system-log.png "The System Log page in
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+ LuCi")
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+
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+The `System Log` page in LuCi does not have an interface for filtering
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+output. Therefore, you will likely want to use the shell interface.
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+
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+## Viewing the System Log from the shell
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+
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+Once logged in via SSH, use the `logread` command
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+
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+```
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+Usage: logread [options]
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+Options:
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+ -s <path> Path to ubus socket
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+ -l <count> Got only the last 'count' messages
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+ -e <pattern> Filter messages with a regexp
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+ -r <server> <port> Stream message to a server
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+ -F <file> Log file
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+ -S <bytes> Log size
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+ -p <file> PID file
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+ -h <hostname> Add hostname to the message
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+ -P <prefix> Prefix custom text to streamed messages
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+ -f Follow log messages
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+ -u Use UDP as the protocol
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+ -t Add an extra timestamp
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+ -0 Use \0 instead of \n as trailer when using TCP
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+```
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+
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+For example:
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+
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+```
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+root@libreCMC:~# logread | grep 'kern\.warn'
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+Mon Jan 15 20:22:01 2018 kern.warn kernel: [ 0.000000] No valid device tree found, continuing without
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+Mon Jan 15 20:22:01 2018 kern.warn kernel: [ 0.000000] Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
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+Mon Jan 15 20:22:01 2018 kern.warn kernel: [ 0.000000] Primary data cache 32kB, 4-way, VIPT, cache aliases, linesize 32 bytes
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+Mon Jan 15 20:22:01 2018 kern.warn kernel: [ 0.669305] Crashlog allocated RAM at address 0x3f00000
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+Mon Jan 15 20:22:01 2018 kern.warn kernel: [ 0.752178] m25p80 spi0.0: found mx25l12805d, expected m25p80
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+```
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+
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+One should be able to use `logread -e` instead of `grep`, but it seems
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+that not all the same regular expressions work for both:
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+
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+```
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+root@libreCMC:~# logread -e 'kern\.warn' # and other similar variations
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+(no output)
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+````
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+
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+The system log is contained in a limited size, circular buffer in
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+memory. So, if you have some process writing messages periodically,
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+this will eventually erase messages that were only written once.
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+
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+## Configuring the system log
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+
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+TODO
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+
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+## Monitoring the system log
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+
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+TODO
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