Program Examples:sys log

'sys.log' is a Linux logger that allows the programmer to document strings while his program is running. We've enabled this feature in MC-Basic context as well.

Printing sys.log

To print sys.log do the following:
1. Connect to the softMC using ssh or serial console.
2. To print the entire log, type in the Linux terminal:

-bash-3.2$ cat /var/sys.log

or
3. To print the last few lines, type in the Linux terminal:

-bash-3.2$ tail -50 /var/sys.log

where '50' is the number of lines that will be printed from the end of the file.

Sending strings to sys.log from MC-Basic context

Globally load the MC library SYSLOG.LIB.
Invoke the function
log_msg(byval debug_level as long, byval log_str as string, byval arg1 as long, arg2, arg3..., arg10) as long

Where the arguments are:

debug_level - Use one of the following constants:

MC_BASIC_LOG_LEVEL_NON = 0
MC_BASIC_LOG_LEVEL_ERROR = 1
MC_BASIC_LOG_LEVEL_WARNING = 2
MC_BASIC_LOG_LEVEL_NOTE = 3
MC_BASIC_LOG_LEVEL_DEBUG = 4
MC_BASIC_LOG_LEVEL_ALL = 5

	IMPORTANT
	Debug level can be set by using telnet

A log message at debug level MC_BASIC_LOG_LEVEL_ERROR will always be displayed in sys.log.
A log message at debug level MC_BASIC_LOG_LEVEL_DEBUG will be displayed in sys.log if the debug level of MC-BASIC in softMC is set to DEBUG.

log_str - A string in printf format

	IMPORTANT
	The string variable used by the function log_msg must be declared GLOBAL as common shared or undefined behavior is expected

arg1 to arg10 - Variables of type LONG that correspond with log_str printf format string. Unused arguments can be set to zero.

log_msg returns 0 if successful or -1 on failure.

Example

The following is an MC program that sends a string to sys.log

common shared log_string as string = "Example string. x = %d. y = %d"

Program

        dim x as long = 5
        dim y as long = 99

        ?log_msg(MC_BASIC_LOG_LEVEL_ERROR, log_string, x, y, 0,0,0,0,0,0,0,0)

End Program

Displaying sys.log after sending a string by typing in the Linux terminal:

-bash-3.2$ cat /var/sys.log