logger command is used to log messages in the system log or syslog. You can log a messages string on the command line or provide a file as input that can contain the message to be logged.
To view the available switches for the logger command:
# logger --help Usage: logger [options] [message] Options: -T, --tcp use TCP only -d, --udp use UDP only -i, --id log the process ID too -f, --file [file] log the contents of this file -h, --help display this help text and exit -S, --size [num] maximum size for a single message (default 1024) -n, --server [name] write to this remote syslog server -P, --port [port] use this port for UDP or TCP connection -p, --priority [prio] mark given message with this priority -s, --stderr output message to standard error as well -t, --tag [tag] mark every line with this tag -u, --socket [socket] write to this Unix socket -V, --version output version information and exit
logger command examples
1. To log the message to standard error and system logs
# logger -s "This is a test message"
2. To log to message to the specified file
# logger -f file "This is a test message"
3. To log the message with specified priority
# logger -p 1 "This is a test message"
4. To mark every line with specified tag
# logger -t TAG "This is a test message"
5. To allow the message to start with a hyphen
# logger -- "This is a test message"