logger "this is a test log."
logger -t test "this is a test log."
logger -t test -s "this is a test log."
对应输出：
Jun 30 15:28:59 (none) user.notice root: this is a test log.
Jun 30 15:28:59 (none) user.notice test: this is a test log.
Jun 30 15:29:00 (none) user.notice test: this is a test log.
logger -t 指定标签，默认是用户名
logger -s hello 输出到stderr和系统日志
logger -p 1 指定优先级
root@OpenWrt:~# logger --help
BusyBox v1.30.1 () multi-call binary.
Usage: logger [OPTIONS] [MESSAGE]
Write MESSAGE (or stdin) to syslog
-s Log to stderr as well as the system log
-t TAG Log using the specified tag (defaults to user name)
-p PRIO Priority (numeric or facility.level pair)
# 查看syslogd使用的配置文件
root@OpenWrt:~# ps | grep syslogd
1615 root 1380 S /sbin/syslogd -f/etc/syslog.conf
# 查看日志输出路径
root@OpenWrt:~# cat /etc/syslog.conf
*.* /var/log/syslog
# 持续查看日志文件
tail -f /var/log/syslog | grep test
