Operating System
****************

Command Line
============

The variable si::*command-args* is set to the list of strings passed in when gcl is invoked.

Various flags are understood.

-eval
     Call read and then eval on the command argument following -eval

-load
     Load the file whose pathname is specified after -load.

-f
     Replace si::*command-args* by the the list starting after -f. Open the file following -f for input, skip the first line, and then read and eval the rest of the forms in the file.   This can be used as with the shells to write small shell programs:

          #!/usr/local/bin/gcl.exe -f
          (format t "hello world ~a~%" (nth 1 si::*command-args*))

     The value si::*command-args* will have the appropriate value. Thus if the above 2 line file is made executable and called foo then

          tutorial% foo billy
          hello world billy

     NOTE:  On many systems (eg SunOs) the first line of an executable script file such as:

          #!/usr/local/bin/gcl.exe -f

     only reads the first 32 characters!   So if your pathname where the executable
     together with the '-f' amount to more than 32 characters the file will not
     be recognized.   Also the executable must be the actual large binary file,
     [or a link to it],
     and not just a /bin/sh script.   In latter case the
     /bin/sh interpreter would get invoked on the file.

     Alternately one could invoke the file foo without making it executable:

          tutorial% gcl -f foo "from bill"
          hello world from bill

-batch
     Do not enter the command print loop.  Useful if the other command line arguments do something.  Do not print the License and acknowledgement information.  Note if your program does print any License information, it must print the GCL header information also.

-dir
     Directory where the executable binary that is running is located. Needed by save and friends.  This gets set as si::*system-directory*

-libdir

             -libdir /d/wfs/gcl-2.0/

     would mean that the files like gcl-tk/tk.o would be found by concatting the path to the libdir path, ie in

          /d/wfs/gcl-2.0/gcl-tk/tk.o

-compile
     Invoke the compiler on the filename following -compile. Other flags affect compilation.

-o-file
     If nil follows -o-file then do not produce an .o file.

-c-file
     If -c-file is specified, leave the intermediate .c file there.

-h-file
     If -h-file is specified, leave the intermediate .h file there.

-data-file
     If -data-file is specified, leave the intermediate .data file there.

-system-p
     If -system-p is specified then invoke compile-file with the :system-p t keyword argument, meaning that the C init function will bear a name based on the name of the file, so that it may be invoked by name by C code.

Operating System Definitions
============================

 -- Function: GET-DECODED-TIME ()
     Package:LISP

     Returns the current time in decoded time format.  Returns nine values: second, minute, hour, date, month, year, day-of-week, daylight-saving-time-p, and time-zone.

 -- Function: HOST-NAMESTRING (pathname)
     Package:LISP

     Returns the host part of PATHNAME as a string.

 -- Function: RENAME-FILE (file new-name)
     Package:LISP

     Renames the file FILE to NEW-NAME.  FILE may be a string, a pathname, or a stream.

 -- Function: FILE-AUTHOR (file)
     Package:LISP

     Returns the author name of the specified file, as a string. FILE may be a string or a stream

 -- Function: PATHNAME-HOST (pathname)
     Package:LISP

     Returns the host slot of PATHNAME.

 -- Function: FILE-POSITION (file-stream &optional position)
     Package:LISP

     Sets the file pointer of the specified file to POSITION, if POSITION is given. Otherwise, returns the current file position of the specified file.

 -- Function: DECODE-UNIVERSAL-TIME (universal-time &optional (timezone -9))
     Package:LISP

     Converts UNIVERSAL-TIME into a decoded time at the TIMEZONE. Returns nine values: second, minute, hour, date, month (1 - 12), year, day-of-week (0 - 6), daylight-saving-time-p, and time-zone. TIMEZONE in GCL defaults to 6, the time zone of Austin, Texas.

 -- Function: USER-HOMEDIR-PATHNAME (&optional host)
     Package:LISP

     Returns the home directory of the logged in user as a pathname.  HOST is ignored.

 -- Variable: *MODULES*
     Package:LISP A list of names of the modules that have been loaded into GCL.

 -- Function: SHORT-SITE-NAME ()
     Package:LISP

     Returns a string that identifies the physical location of the current GCL.

 -- Function: DIRECTORY (name)
     Package:LISP

     Returns a list of files that match NAME.  NAME may be a string, a pathname, or a file stream.

 -- Function: SOFTWARE-VERSION ()
     Package:LISP

     Returns a string that identifies the software version of the software under which GCL is currently running.

 -- Constant: INTERNAL-TIME-UNITS-PER-SECOND
     Package:LISP The number of internal time units that fit into a second.

 -- Function: ENOUGH-NAMESTRING (pathname &optional (defaults *default-pathname-defaults*))
     Package:LISP

     Returns a string which uniquely identifies PATHNAME with respect to DEFAULTS.

 -- Function: REQUIRE (module-name &optional (pathname))
     Package:LISP

     If the specified module is not present, then loads the appropriate file(s). PATHNAME may be a single pathname or it may be a list of pathnames.

 -- Function: ENCODE-UNIVERSAL-TIME (second minute hour date month year &optional (timezone ))
     Package:LISP

     Does the inverse operation of DECODE-UNIVERSAL-TIME.

 -- Function: LISP-IMPLEMENTATION-VERSION ()
     Package:LISP

     Returns a string that tells you when the current GCL implementation is brought up.

 -- Function: MACHINE-INSTANCE ()
     Package:LISP

     Returns a string that identifies the machine instance of the machine on which GCL is currently running.

 -- Function: ROOM (&optional (x t))
     Package:LISP

     Displays information about storage allocation in the following format.

       * for each type class

            * the number of pages so-far allocated for the type class

            * the maximum number of pages for the type class

            * the percentage of used cells to cells so-far allocated

            * the number of times the garbage collector has been called to collect cells of the type class

            * the implementation types that belongs to the type class

       * the number of pages actually allocated for contiguous blocks

       * the maximum number of pages for contiguous blocks

       * the number of times the garbage collector has been called to collect contiguous blocks

       * the number of pages in the hole

       * the maximum number of pages for relocatable blocks

       * the number of times the garbage collector has been called to collect relocatable blocks

       * the total number of pages allocated for cells

       * the total number of pages allocated

       * the number of available pages

       * the number of pages GCL can use.

          The number of times the garbage collector has been called is not shown, if the number is zero.  The optional X is ignored.

 -- Function: GET-UNIVERSAL-TIME ()
     Package:LISP

     Returns the current time as a single integer in universal time format.

 -- Function: GET-INTERNAL-RUN-TIME ()
     Package:LISP

     Returns the run time in the internal time format.  This is useful for finding CPU usage.  If the operating system allows, a second value containing CPU usage of child processes is returned.

 -- Variable: *DEFAULT-PATHNAME-DEFAULTS*
     Package:LISP The default pathname-defaults pathname.

 -- Function: LONG-SITE-NAME ()
     Package:LISP

     Returns a string that identifies the physical location of the current GCL.

 -- Function: DELETE-FILE (file)
     Package:LISP Deletes FILE.

 -- Function: GET-INTERNAL-REAL-TIME ()
     Package:LISP

     Returns the real time in the internal time format.  This is useful for finding elapsed time.

 -- Function: MACHINE-TYPE ()
     Package:LISP

     Returns a string that identifies the machine type of the machine on which GCL is currently running.

 -- Macro: TIME
     Package:LISP

     Syntax:

          (time form)

     Evaluates FORM and outputs timing statistics on *TRACE-OUTPUT*.

 -- Function: SOFTWARE-TYPE ()
     Package:LISP

     Returns a string that identifies the software type of the software under which GCL is currently running.

 -- Function: LISP-IMPLEMENTATION-TYPE ()
     Package:LISP

     Returns a string that tells you that you are using a version of GCL.

 -- Function: SLEEP (n)
     Package:LISP

     This function causes execution to be suspended for N seconds.  N may be any non-negative, non-complex number.