From:	MERC::"uunet!WKUVX1.BITNET!MacroMan" 28-APR-1993 11:03:36.79
To:	MACRO32@WKUVX1.BITNET
CC:	
Subj:	RE: PRC$M_NETWORK (was Re: $creprc ...)

Wolfgang J. Moeller <moeller@gwdgv1.dnet.gwdg.de> wrote
a program to create a network process.

Thanks...

>        .title  zlnp    create a network process with PROXY access (VMS V5)
>;
>; as of VMS 5.5-1, SYS$OUTPUT for a NETWORK process looks as follows:
>;------------------------------
>;       .word   proxy_flags
>;  .if (proxy_flags & 1)                        ;; new
>;       .ascic  proxy_username                  ;; with
>;  .endif                                       ;; VMS V5
>;       .ascic  username
>;       .ascic  password
>;       .ascic  account
>;------------------------------
>; Note: the trailing fields *must* be present; they may be 0, of course.
>;
>; If a proxy-login is attempted and the proxy_username is not in SYSUAF,
>; the following (standard) access info will be used; otherwise proxy-login
>; will succeed.
>; Proxy logins are allowed even for accounts with "AUTOLOGIN" flag.
>;
>; Symbolic codes for proxy_flags (LGI$V_NET_*) are defined
>; in LIB.REQ starting with VMS 5.5:
>;       LGI$V_NET_PROXY = 0
>;       LGI$V_NET_PREAUTH = 1
>; New with VMS 5.5: a non-proxy login with NET_PREAUTH set
>; will not check the password (similar to a proxy request).
>;
>; The above proxy handling apparently was introduced with VMS V5;
>; formerly LOGINOUT would require both username and password.
>;
>; SYS$ERROR as specified will be put into the network process's
>; SYS$NET logname. As of VMS 5.5, some additional magic(??) will be done
>; if the SYS$ERROR string contains a '/' (slash) character!
>;
>; The network process's SYS$OUTPUT and SYS$ERROR are always directed
>; to a .LOG file, with name derived from SYS$INPUT (but in the user's
>; default directory). Traditionally, the original SYS$INPUT can be
>; found in the "TT" process logname.
>;
>; Note: PRC$M_NOPASSWORD has effect for interactive logins only.
>;
>;*****
>;
>        $prcdef
>;
>image:  .ascid  "SYS$SYSTEM:DCL.EXE"    ; just for fun - same effect as
>                                        ; specifying SYS$SYSTEM:LOGINOUT.EXE
>input:  .ascid  "SYS$MANAGER:00.COM"    ; command procedure to be executed,
>                                        ; logfilespec will be SYS$LOGIN:00.LOG
>error:  .ascid  "cont_of_net"           ; this string goes into SYS$NET -
>                                        ; no '/' here, please!??
>out_b:  .word   1               ;ask for proxy
>        .ascic  "MOELLER"       ;proxy user
>        .ascic  "DECNET"        ;(default user, only used in case of error)
>        .ascic  ""              ;(default password)
>        .ascic  ""              ;(default "account" - ignored anyway)
>out_l=.-out_b
>output: .long   out_l
>        .address out_b
>priv:   .long   -1,-1           ; /priv=ALL doesn't hurt, but isn't required
>prcnam: .ascid  "00_NET"        ; process name
>;
>.entry  begin,^m<>
>        $creprc_s       -
>                image=image,-
>                input=input,-
>                output=output,-
>                error=error,-
>                prvadr=priv,-
>                prcnam=prcnam,-
>                baspri=#4,-
>                uic=#^x00010004,-
>                stsflg=#prc$m_netwrk
>        ret
>;
>        .end    begin
>

I wondered why it changed the username of the process running this program.
Well, stsflg should be #PRC$M_NETWRK!PRC$M_DETACH.
Otherwise the network process becomes a subprocess of the process
running this program, and LOGINOUT.EXE (DCL.EXE) changes
the username which is in the JIB.

So SET PROCESS/USER=<user> can be implemented by calling sys$creprc with
PRC$M_NETWRK if you have DETACH privilege.

/Carlo Mekenkamp <DNW@NLR.NL>