xlog

Application logging library

Quick look at features:

• Optionally Time-stamped formatted log entries 2021-10-27 13:55:36.423013 xlog: end of log-file 2021-10-27_dispatch-rescancanm.log

• Log files can be appended to or superseded

• Log directory can be specified (with-open-log-file (<filespec> :dir "<log file directory>") ... )

• Log file extension can be specified

  (with-open-log-file (<filespec> :extension "out") ... )

• Log entry can be also pushed to standard out Usual output is (xlogf "" ) ; in the manner of (format ...) Copy to standard output is

  (xlogft "<format string>" ... _)

• Alert file support for status reporting Set alert file name: (set-alert-file-name "<name of alert file>").

  (xalert "simple string") ; opens alert file, writes values, closes alert file (xlalertf "format string" <val1> ... )

• Support for date-stamped file names with options for hour,minute,second resulution, hour resolution, date only, or no date. (with-open-log-file ("filespec" :dates (t :hms :hour :dates)

• Log files can be nested. The with-open-log-file macro wraps code in the manner of with-open-file. If you nest the calls, upon closing the nested open, the original one resumes. This can ease reading detail processes within a global process.

Stackable log files

Log files can be nested. A second consecutive log file opening will push the existing log file and name onto a stack. If show-log-file-name is set, the name of the new log file will be written to the existing one. Once the new log file is opened, the name of the previously opened log file will be logged.

Alert file

The purpose of the alert file is to provide a short status for other programs to inspect without analyzing the log file.

set-alert-file-name (name)

xalertf(fmt vars)

Write an alert to the alert file and to the log file.

Functions:

Answer the version

(xlog-version)

Unpack a utc time that has hyphens.

For an example string 2024-05-30 00:00:01.593760, answer multi-value seconds and milliseconds.

unpack-utc-with-hyphens(utc-string)

For a timestampe formatted by how long ago was the 'tim' timestamp,

2024-05-30 00:00:01.593760

calc-elapsed-time (tim)

Produce a formatted timestamp from the current time

formatted-current-time-micro (str)

Answer the mtime (formatted) of a file and its age

formatted-file-time (filename)

Format the current time

formatted-current-time ()

Format dates

dates-ymd (datecmd)

For values of datecmd

• :hms Format the date with month, day, year, hours, minutes, and seconds.
• :hour Format the date with month, day, year, and hour
• t Format the date year, month, day

Conditional debug macro

debugc (val stmt)

If val is less than or equal to *debug-level*, evaluate stmt.

Write line to log

xlog(str)

Write a time-stamped line to the log file. All log entries come through this function. Items written the log file end with a new line. Lines are forced to begin at the first position by the use of fresh-line.

Write a line without time prefix to the log file.

xlognt

As xlog, but without time prefix.

Flush the log file

xlogfin

Write a line to the log file using a specified format.

xlogf (fmt vars)

Write a formatted line to the log file, and flush the output.

xlogff(fmt vars)

Write a formatted time-stamped line to the log file and to standard output

xlogft(fmt vars)

Write a formatted non-time-stamped line to log file

xlogntf(fmt vars)

Write a non-time-stamped formatted line to the log file and standard output.

xlogntft

Portability