sde(5)                     DG/UX 4.30                      sde(5)



     NAME
          sde - software development environment

     DESCRIPTION
          A software development environment (SDE) is a set of files,
          libraries, and tools used to develop software.  More
          specifically, an SDE resides in the following system
          directories, known as the SDE domain:

               /bin         /usr/bin            /usr/man
               /etc         /usr/catman         /usr/opt
               /lib         /usr/etc            /usr/sbin
               /opt         /usr/include
               /sbin        /usr/lib

          Many pathnames in these directories have well established
          meanings:

               The shell invokes the C compiler as /bin/cc.
               A compiler invokes the linker as /bin/ld.
               A preprocesor reads <errno.h> from /usr/include/errno.h.
               The linker binds a program with /usr/lib/libc.a.

          Until now, it has been conventional for UNIX* systems to
          supply a single SDE.  The DG/UX system supplies more than
          one SDE.  The SDE mechanism allows multiple SDEs to reside
          on a system while retaining the meaning of the pathnames in
          the SDE domain.  The user selects the desired SDE with the
          sde-target(1) command, and subsequent operations are then
          directed to the established SDE.

          An SDE is identified by the name of a directory in /usr/sde.
          This directory is the root of the SDE domain for that SDE.
          For example, the m88kbcs SDE resides in /usr/sde/m88kbcs.
          After issuing the command targ m88kbcs (see sde-target(1)),
          the environment variable SDETARGET is set to m88kbcs.  This
          establishes the m88kbcs SDE.

          The SDE mechanism alters the pathnames used by ar(1),
          attdump(1), ld(1), nm(1), and size(1), based on the value
          of the SDETARGET environment variable.  If one of these
          commands operates on a file in the SDE domain, the
          corresponding file in the established SDE is substituted if
          it exists.  In the m88kbcs SDE, there is a different version
          of /usr/lib/libc.a.  It resides in the file system as
          /usr/sde/m88kbcs/usr/lib/libc.a.  When ld binds a program
          with /usr/lib/libc.a, the SDE mechanism will substitute the
          version in the m88kbcs SDE.

          Currently, there are two SDEs:  the default SDE and the
          m88kbcs SDE.  Thus, the only directory in /usr/lib/sde is
          m88kbcs; the default SDE resides in the root (/).  The



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     sde(5)                     DG/UX 4.30                      sde(5)



          default SDE is used to build programs that will execute on
          the M88100 under the DG/UX operating system; the m88kbcs SDE
          is used to build programs that adhere to the 88open Binary
          Compatibility Standard (BCS) and execute under conforming
          operating systems.

          The m88kbcs SDE differs from the default SDE in two
          respects:  it has a different set of libraries, and
          executables built for that environment have a different
          magic number.  To support these differences, the utilities
          configured to use the SDE mechanism are:  ar(1),
          attdump(1), ld(1), nm(1), and size(1).  Additionally, ld(1)
          searches the file /etc/sdetab (sdetab(4)) for the key
          FMAGIC.  If found, its value is used as the executable's
          magic number.

     SEE ALSO
          sde-target(1), sdetab(4)





































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