RSD1901@TAMSIGMA.BITNET.UUCP (01/21/88)
I'm posting this to the entire list as there have been a couple of questions about $TRNLNM as of late... >Dear InfoVaxers, > This is my third try at this so my apologys is it comes thru >more then once. My mailer is somewhat braindead and keeps coming >back and telling me it doesn't know where to send messages if it can't >find send my message. Ow well, here goes nothing. > > > Its friday and maybe thats why I can't figure this out but maybe >someone else can help. I am trying to use the system service sys$trnlnm >to translate a logical name. However, how to define the struct for the >itemlst eludes me. All I want to do is have in my hot little hands a >pointer to a string containing the translated logical. Can anyone >help? > > Thanks > > Al Saganich, Systems Analyst, Mass General Hosp. > Saganich%frodo.decnet@mghccc.harvard.edu > > >heres what I'm trying to do. > >#include <STDIO.h> >#include <SSdef.h> /* the system reurn codes */ >#include <Descrip.h> /* the descriptor definitions */ >#include <Llndef.h> /* the attributes to $trnlnm */ > >/* translate the give logical name and print the translation */ >main() >{ >int sys$trnlnm(); > >$DESCRIPTOR(Log_nam,"EDTINI"); >$DESCRIPTOR(Tab_nam,"PROCESS"); > >sys$trnlnm(NULL,&Tab_nam,$Log_nam,NULL,&itemlst) > >printf("%s\n",somestringpointer} >------ Al, Here's a way to do it with an RTL routine instead of SYS$TRNLNM. It calls SYS$TRNLNM for you and you don't have to fool with item lists. { static struct dsc$descriptor_s translation_dsc={(maximum length of trans.),DSC$K_DTYPE_T,DSC$K_CLASS_S}; $DESCRIPTOR(lognam_dsc,"LOGNAME"); char *translation[(max. len. trans.)]; static int translen,ssrc; translation_dsc.dsc$a_pointer=translation; ssrc=lib$sys_trnlog(&lognam_dsc,&translen,&translation_dsc,0,0,0); printf("%s\n",translation); } translation_dsc -- descriptor for translation lognam_dsc -- descriptor for logical name to be translated translation -- character string to contain translation translen -- length of translation ssrc -- return code from system service lib$sys_trnlog -- RTL routine which calls $TRNLNM for you If you need to specify the table name (if you're translating something which is only listed in one table you won't need to), the table name can be specified following the "translation_dsc" actual parameter in this particular call. The last two arguments are for the access mode for the logical you're seeking and the mask of tables in which to search for it if they are not the same as LNM$PROCESS_DIRECTORY or you wish to disable searching in one particular table. I've never used these arguments so you'll have to look in your Run-Time Library manual if you need them. You may have a problem with extraneous characters at the end of your translation. In that case, you'd have to do a strncpy(translation,newtrans, translen) to keep only the number of characters returned from the system service by the parameter "translen". The "#include" directives you have in there will be sufficient. Good luck... --Shane Davis Texas A&M Univ. Software Systems Group ******************************************************************************** BITnet THEnet Internet XPMAINT@TAMVENUS THOR::XPMAINT xpmaint@venus.tamu.edu RSD1901@TAMSIGMA ZAC::RSD1901 -------- X222SD@TAMVM1 ------ x222sd@tamvm1.tamu.edu ------ CONS::RSD1901 rsd1901@cons.tamu.edu SPAN: UTSPAN::UTADNX::(THEnet addr) ********************************************************************************
sarge@con.Berkeley.EDU (Steven Sargent) (01/29/88)
We do something like this as well. The one thing that I have to add is that "process-permanent" logical names (e.g, SYS$INPUT) have a 4-byte booger prepended to their translations. In our "getenv" replacement routine, we snarf up the logical name translation and then say words like: return (*p == '\33')? p+4: p; to get around it. (Anybody know what that 4 bytes of stuff is?) S.
hydrovax@nmtsun.nmt.edu (M. Warner Losh) (01/31/88)
In article <429@pasteur.Berkeley.Edu>, sarge@con.Berkeley.EDU (Steven Sargent) writes: > "process-permanent" logical names (e.g, SYS$INPUT) have a 4-byte > booger prepended to their translations. > [...] > (Anybody know what that 4 bytes of stuff is?) According to one of the manuals that I was looking through recently (yes, it is for VMS :-), the first byte is an escape character (\033) while the other three point to something called an RMS internal file number. The manual claims that this speeds things up quite a bit. -- bitnet: losh@nmt.csnet M. Warner Losh warner@hydrovax.nmt.csnet ! Don't know if this works, let me know. csnet: warner@hydrovax.nmt.edu uucp: ...{cmcl2, ihnp4}!lanl!unmvax!nmtsun!warner%hydrovax
jumper@trwrb.UUCP (Gregory S. Jumper) (02/01/88)
The four-byte header in the equivalence string of a logical name which refers
to a process-permanent file contains the "escape" and "null" characters,
followed by two bytes representing the RMS Internal File Identifier for that
process-permanent file. This header allows for faster access to these files.
Greg Jumper
ARPA Internet: trwrb!jumper@trwind.TRW.COM
UUCP: ...{decvax,ihnp4,ucbvax}!trwrb!jumperdave@terminus.UUCP (VAX Headroom @ The End of the Galaxy) (02/03/88)
I believe the first 4 bytes at the beginning of things like SYS$INPUT and SYS$OUTPUT are an ISI, and RMS internal stream identifier. These files are always open and rms uses this to identify the "channel" being used to communicate with the entity pointed to by the logical name. -- ...ihnp4!utah-cs!utah-gr!uplherc!sp7040!obie!terminus!trntor.dnet!dave "...between the streets of dallas and the beaches of miami...this was max headroom's finest hour."