More doc updates, fix initialization on VAX/VMS.

1 files changed, 40 insertions, 6 deletions

diff --git a/doc/gawktexi.in b/doc/gawktexi.in
index 51b90877..fc465648 100644
--- a/doc/gawktexi.in
+++ b/doc/gawktexi.in
@@ -34012,7 +34012,7 @@ The older designation ``VMS'' is used throughout to refer to OpenVMS.
 
 To compile @command{gawk} under VMS, there is a @code{DCL} command procedure
 that issues all the necessary @code{CC} and @code{LINK} commands. There is
-also a @file{Makefile} for use with the @code{MMS} or @code{MMK} utility.
+also a @file{Makefile} for use with the @code{MMS} and @code{MMK} utilities.
 From the source directory, use either:
 
 @example
@@ -34033,8 +34033,8 @@ or:
 $ @kbd{MMK/DESCRIPTION=[.vms]descrip.mms gawk}
 @end example
 
-@code{MMK} is an open source freeware near clone of @code{MMS} and
-can better handle @code{ODS-5} volumes with upper- and lower-case filenames.
+@code{MMK} is an open source, free, near-clone of @code{MMS} and
+can better handle @code{ODS-5} volumes with upper- and lowercase filenames.
 @code{MMK} is available from @uref{https://github.com/endlesssoftware/mmk}.
 
 With @code{ODS-5} volumes and extended parsing enabled, the case of the target
@@ -34060,9 +34060,10 @@ a PCSI kit for compatible with the GNV product.
 @appendixsubsubsec Compiling @command{gawk} Dynamic Extensions on VMS
 
 Dynamic extensions need to be compiled with the same compiler options for
-floating point, pointer size, and symbol name handling as @command{gawk}.
+floating point, pointer size, and symbol name handling as were used
+to compile @command{gawk} itself.
 Alpha and Itanium should use IEEE floating point.  The pointer size is 32 bits,
-and the symbol name handling is to be exact case with CRC shortening for
+and the symbol name handling should be exact case with CRC shortening for
 symbols longer than 32 bits.
 
 For Alpha and Itanium:
@@ -34176,6 +34177,39 @@ flag is required to force Unix-style parsing rather than @code{DCL} parsing.  If
 other dash-type options (or multiple parameters such as data files to
 process) are present, there is no ambiguity and @option{--} can be omitted.
 
+@cindex exit status, of VMS
+The @code{exit} value is a Unix-style value and is encoded to a VMS exit
+status value when the program exits.
+
+The VMS severity bits will be set based on the @code{exit} value.
+A failure is indicated by 1 and VMS sets the @code{ERROR} status.
+A fatal error is indicated by 2 and VMS will set the @code{FATAL} status.
+All other values will have the @code{SUCCESS} status.  The exit value is
+encoded to comply with VMS coding standards and will have the
+@code{C_FACILITY_NO} of @code{0x350000} with the constant @code{0xA000}
+added to the number shifted over by 3 bits to make room for the severity codes.
+
+To extract the actual @command{gawk} exit code from the VMS status use:
+
+@example
+unix_status = (vms_status .and. &x7f8) / 8
+@end example
+
+@noindent
+A C program that uses @code{exec()} to call @command{gawk} will get the original
+Unix-style exit value.
+
+Older versions of @command{gawk} treated a Unix exit code 0 as 1, a failure
+as 2, a fatal error as 4, and passed all the other numbers through.
+This violated the VMS exit status coding requirements.
+
+@cindex floating-point, VAX/VMS
+VAX/VMS floating point uses unbiased rounding. @xref{Round Function}.
+
+VMS reports time values in GMT unless one of the @code{SYS$TIMEZONE_RULE}
+or @code{TZ} logical names is set.  Older versions of VMS, such as VAX/VMS
+7.3 do not set these logical names.
+
 @c @cindex directory search
 @c @cindex path, search
 @cindex search paths
@@ -34193,7 +34227,7 @@ translation and not a multitranslation @code{RMS} searchlist.
 The VMS GNV package provides a build environment similar to POSIX with ports
 of a collection of open source tools.  The @command{gawk} found in the GNV
 base kit is an older port.  Currently the GNV project is being reorganized
-to be individual PCSI packages for each component.
+to supply individual PCSI packages for each component.
 See @uref{https://sourceforge.net/p/gnv/wiki/InstallingGNVPackages/}.
 
 The normal build procedure for @command{gawk} produces a program that