dmerg

Command line utility to merge the standard output and the kernel ring buffer.

By default dmerg collects kernel logs from the systemd journal. Only members of the groups "systemd-journal", "adm", and "wheel" can read all journal files. Alternatively, dmerg can be told to use dmesg output. In such case, beware of dmesg time not being in sync with the system clock. Unless otherwise told, dmerg picks kernel log messages with a date that is newer than the time of its execution. dmesg messages showing a clock that is late, will delay the starting point of kernel message collection.

Options

~$ ./dmerg -h
dmerg 0.1.0

USAGE:
    dmerg [FLAGS] [OPTIONS]

FLAGS:
    -c, --console-off    Do not write to the standard output
    -d, --dmesg          Use dmesg instead of journald
    -f, --full           Include full kernel log output
    -h, --help           Prints help information
    -V, --version        Prints version information

OPTIONS:
    -o, --output <output>    Write output to <output> instead of a random file

Example

~$ for i in {1..10}; do echo $i; sleep 1; done | ./dmerg
2021-09-17T18:41:02.668895+0000 1
2021-09-17T18:41:03.663459+0000 2
2021-09-17T18:41:04.672363+0000 3
2021-09-17T18:41:05.055183+0000 test kernel: Unloaded Memory Tracer
2021-09-17T18:41:05.079075+0000 test kernel: Memory Tracer
2021-09-17T18:41:05.674361+0000 4
2021-09-17T18:41:06.674690+0000 5
2021-09-17T18:41:06.350965+0000 test kernel: Unloaded Memory Tracer
2021-09-17T18:41:06.375967+0000 test kernel: Memory Tracer
2021-09-17T18:41:07.678787+0000 6
2021-09-17T18:41:07.343006+0000 test kernel: Unloaded Memory Tracer
2021-09-17T18:41:07.368014+0000 test kernel: Memory Tracer
2021-09-17T18:41:08.683783+0000 7
^C
+ Output written to dmerged.Td8j7omccwVump41

~$ cat dmerged.Td8j7omccwVump41
2021-09-17T18:41:02.668895+0000 1
2021-09-17T18:41:03.663459+0000 2
2021-09-17T18:41:04.672363+0000 3
2021-09-17T18:41:05.055183+0000 test kernel: Unloaded Memory Tracer
2021-09-17T18:41:05.079075+0000 test kernel: Memory Tracer
2021-09-17T18:41:05.674361+0000 4
2021-09-17T18:41:06.350965+0000 test kernel: Unloaded Memory Tracer
2021-09-17T18:41:06.375967+0000 test kernel: Memory Tracer
2021-09-17T18:41:06.674690+0000 5
2021-09-17T18:41:07.343006+0000 test kernel: Unloaded Memory Tracer
2021-09-17T18:41:07.368014+0000 test kernel: Memory Tracer
2021-09-17T18:41:07.678787+0000 6
2021-09-17T18:41:08.683783+0000 7