The log_listener binary is included in all device builds that include pkgfs and is currently
the primary tool used by engineers to interactively read a live log stream. In-tree developers
usually invoke it with ffx log.
| Flag | Notes |
--only <comma-separated-words>
|
Include lines containing at least one of the specified words. If this is not set, it has no effect. |
--suppress <comma-separated-words>
|
Exclude lines containing any of the specified words. |
--select <comma-separated-component-interests>
|
Configure the minimum severity level for logs emitted by components on the target device
matching the selector.
Specify using the format <component-selector>#<log-level>, where
log-level must be one of FATAL|ERROR|WARN|INFO|DEBUG|TRACE.
Multiple component selections are delimited by commas. |
--begin <comma-separated-words>
|
Include blocks starting with at least one of the specified words. Pair with the --end flag. Defaults to off.
|
--end <comma-separated-words>
|
Exclude blocks starting with at least one of the specified words. Pair with the --begin flag. Defaults to off.
|
--tag <string>
|
Tag(s) to include. Use multiple times for multiple tags. By default no tag filtering is performed, only specified tags are allowed if any are specified. |
--ignore-tag <string>
|
Tag(s) to ignore. Use multiple times for multiple tags. |
--pid <integer>
|
Only print logs from the given process koid. |
--tid <integer>
|
Only print logs from the given thread koid. |
--pretty yes
|
Activate colors. |
--hide_metadata yes
|
Hides extraneous metadata (such as PID, TID) from log output. When paired with
--pretty, lines are colorized by severity.
|
--severity <level>
|
Minimum severity to include. Defaults to INFO.
Does not have any impact on the logs produced by components.
|
--file <string>
|
Path where logs will be written. By default logs are written to stdout. |
--file_capacity <integer>
|
The maximum allowed amount of disk space to consume. Once the file being written to reaches
half of the capacity, it is moved to FILE.old and a new log file is created.
Defaults to 64000. If --file is not specified, it has no effect. Setting to 0 disables this functionality. |
--startup_sleep <integer>
|
Sleep for this number of milliseconds on program startup. |
--clock <Monotonic|UTC|Local>
|
Clock to use when printing timestamps.
Monotonic (default): Monotonic time reported by the kernel. UTC: UTC time as reported by the runtime. Local: Localized wall time. |
--time_format <format>
|
If --clock is not MONOTONIC, specify timestamp format.
See the chrono crate's docs for format specifiers. Defaults to "%Y-%m-%d %H:%M:%S". |
--since_now yes
|
Ignore all logs from before this command is invoked. |
--dump_logs yes
|
Exit after printing already-available logs. |
--help | -h
|
Prints usage. |