Open a log file, and control whether command lines are echoed.
XSPEC> log <log file> <log command chat> <indirect adjustment>
where <log file> is the name of the file to be opened (default extension is .log). If no arguments are on the line, then the default file name is xspec.log. If <log file> matches the string none, then the current log file is closed. <log command chat> is an integer that determines the importance of echoing the input command lines on the log file. The line is not echoed if <log command chat> is greater than the current log chattiness level (see the chatter command). <indirect adjustment> is an integer added to the value of <log command chat> for every nested level of indirection in the command processor (i.e., the use of command files). The default values of <log command chat> and <indirect adjustment> are 10 and 1.