options.doc

汇编大全 中国矿业大学计算机学院 汇编实验5

/* derived from: options.doc 1.4 88/08/22 15:24:59 */
/* $Source: /usr/home/dhesi/zoo/RCS/options.doc,v $ */
/* $Id: options.doc,v 1.5 91/07/09 02:53:10 dhesi Exp $ */

Documentation about the file options.h.

The file options.h defines various symbols and macros that are needed
to ensure system-independence.  The basic philosophy is to use a
distinct symbol for each attribute that varies from machine to machine.
Then, for each new system, we define symbols corresponding to its
attributes. Thus, ideally, the only place in Zoo code that we actually
use the name of a machine is in this file, in portable.h, and possibly in
machine.h and options.c.  Everywhere else in the code we only use
names of attributes.

LOOK IN THE FOLLOWING FILES WHEN MAKING CHANGES TO SUPPORT A NEW SYSTEM:

	  options.h, portable.h, machine.c

ALSO GLANCE AT THESE FILES TO MAKE SURE THEY WILL WORK:

	  zooio.h, machine.h

Machine names:

MSC         Microsoft C under MS-DOS      (not currently in use)
TURBOC      Turbo C++ 1.0 under MS-DOS    (works, compiled version is
                                          separately distributed)
SYS_V       Most releases of System V     (works)
VMS         VAX/VMS 5.4                   (works, stream-LF files only)
BSD4_3      4.3BSD an most derivatives    (works)
MCH_AMIGA   AmigaDOS Aztec/Manx C         (not tested; compiled version
														 will eventually follow)


MERGED OR MIXED SYSTEMS.  Many vendors of **IX systems take one of the
two (System V or BSD) and add features from the other.  In some cases
they do a terrible job of reconciling irreconcilable differences between
the two, such that the merged system will now compile neither System V
stuff nor BSD stuff.  If you are dealing with such a system, try 
compiling with both BSD4_3 and SYS_V in turn, and see if one of them
works.  If not, then go through the list of compilation symbols below
and pick a set that matches your system.

------------------------------------------------------------------------
NOTE:  The term "zoofile" below refers to an open file of type
ZOOFILE.  Currently this is defined to be equivalent to a standard
buffered file pointer of type "ZOOFILE *" but this could change in the
future.  Dependence on exact definition of ZOOFILE is localized to a
few files:  options.h, portable.h, portable.c, and machine.c.
------------------------------------------------------------------------

Attributes of systems:

CHEKDIR
   Test each supplied filename and if it is a directory or other special
   type of file, do not try to add it to an archive.  If CHEKDIR is
   defined, then machine.c must also contain function isadir() that
   tests a supplied zoofile and returns 1 if it corresponds to a
   directory or other special type of file, else 0.
CHEKUDIR
   Like CHEKDIR but use function isuadir() that tests a pathname, not
   a zoofile.  Both CHEKDIR and CHEKUDIR may be defined, if both
   functions isadir() and isuadir() are available;  in this case
   zoo code will use both and will execute slightly faster.
   (However, simultaneous definition of CHEKDIR and CHEKUDIR has
   not been tested.)
DISK_CH
   If defined, must hold the value of a character that separates a
   disk name from the rest of the pathname.  All characters up to and
   including this character will be removed from a pathname before it
   is stored in an archive.  Usually a colon (':').
EXISTS
   If defined, is assumed to be a macro that accepts a filename and
   returns an int value of 1 if the file exists and 0 if it doesn't.
   If not defined, existence of files is tested by attempting to open
   them for read or write access.
FATTR
   If defined, file attributes will be preserved.  A function
   getfattr(f) must also exist that returns the attributes of a
   zoofile f (or of a pathname f, if the symbol FATTR_FNAME is
   also defined); and a function setfattr(f, a) must exist that
   sets the attributes of a file with pathname f to the value a.
   For more details see the source code in sysv.c and bsd.c.  Currently
   the attribute value a is required to be in the zoo portable
   format.  The lowest nine bits of this format correspond to
   the **IX mode bits described for chmod(2) and these are the only
   bits currently used.
FATTR_FNAME
   If defined, and if FATTR is also defined, zoo code will
   obtain the attributes of a file by calling the function
   getfattr(f) and supplying it with filename f.  If FATTR_FNAME
   is not defined, then getfattr(f) is supplied a zoofile f.
ANSI_PROTO
   Use ANSI-style function prototypes declarations.
VOIDPTR
   The type of a generic pointer, as returned by malloc().  This
   should be defined as void * in an ANSI C environment.  In most
   other environments it will be char *.
LINT
   If defined, SCCS identifier strings will not be included in the
   generated code.  This will make the code smaller and will also
   avoid complaints from lint about unused variables.  This symbol
   should be defined in the Makefile, NOT in `options.h', otherwise
   it will not be fully effective.
FOLD
   Fold filenames to lowercase.  Define this for case-insensitive filesystems
FPUTCHAR
   If defined, a library function fputchar() is assumed available
   that is like fput() but is a function, not a macro, to save
   space.  If not defined Zoo uses its own fputchar() function.
PORTABLE
   Use portable functions --- define for every system except MS-DOS
PURIFY
   When filenames are being read from standard input, ignore all
   characters begining with the first blank or tab encountered.
   This will allow filenames to be fed from a program that produces
   lines containing filenames followed by other information that
   should be ignored.  Should be defined for most non-**IX systems.
DONT_SORT
   Don't sort filename arguments -- files will be stored in the
   exact order in which names are supplied on the command line.
   Not currently used for any system, but could be used if memory
   is really tight.
NOENUM
   Compiler does not support enumerations
FNLIMIT
   Pathname length limit for this system
NEEDCTYP
   If defined, tells the code to include the header file ctype.h for
   use by character conversion macros.  If and only if NEEDCTYP is not
   defined, macros or appropriate function declarations can be put in
   portable.h.  Zoo uses isupper(), isdigit(), toascii(), and tolower().
   If NEEDCTYP is not defined, the symbol USE_ASCII can be defined to
   cause zoo to assume the ASCII character set and use its own isupper(),
   isdigit(), toascii(), and tolower() functions, possibly making the
   executable code smaller.
USE_ASCII
   See description of NEEDCTYP.  USE_ASCII should not be defined if
   NEEDCTYP is defined, else there may be conflicts between macro
   and function names.
NIXTIME
   If defined, a function setutime() must be defined that will set the
   date and time of a file whose pathname is supplied.  If not defined,
   a function settime() must be defined that will do the same for
   a zoofile.
GETUTIME
   If defined, a function getutime() must be defined that will return
   the MS-DOS format date and time of the specified filename.  If this
   symbol is not defined, then a function gettime() must be defined
   that will do the same for a zoofile instead of a filename.
NOSIGNAL
   Don't use signals because library doesn't support them
T_SIGNAL
   The data type returned by a signal handler.  Historically
   "int", but "void" in ANSI C.
PATH_CH
   The character that separates the directory name from the filename
   in a pathname.  String value.
PATH_SEP
   The set of characters that may separate preceding directory/device