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The Question is:
I am trying to get the date-time information in a C program which used FAB,
RAB, and XAB (which I don't know how to use)... How do I start from FAB,
opening the file for reading, and print out the date=time of creation?
Here is what I have been trying...:::
struct FAB infab, *fab
struct RAB inrab, *rab;
struct XABDAT inxab;
infab = cc$rms_fab;
inxab = cc$rms_xabdat;
...
infab.fab$l_xab = &inxab;
...
fab = &infab;
stat = sys$open ( fab );
...
stat = sys$display ( fab );
...
printf("VMS_FILE_inxab = {%ld %ld};",inxab.xab$q_cdt,inxab.xab$q_rdt);
...
Am I close? Could I get a code fragment that shows the correct sequence of
calls? Thanks.
I work for NASA in Greenbelt in a VMS cluster, and am having much success,
except for this. Plus, I would LOVE to get the values in an ASCII string...
Can you help me?
Mark.
The Answer is :
The C fstat() call would seem useful, if this is a file accessed via
native C library calls. The field st_ctime is the time_t value the
file was created.
Also see topics (6916), (1023), (5424), (6744), (6884).
As for RMS, the consider following:
/*
** COPYRIGHT (c) 1992-1999 BY
** DIGITAL EQUIPMENT CORPORATION, MAYNARD, MASSACHUSETTS.
** ALL RIGHTS RESERVED.
**
** THIS SOFTWARE IS FURNISHED UNDER A LICENSE AND MAY BE USED AND COPIED
** ONLY IN ACCORDANCE OF THE TERMS OF SUCH LICENSE AND WITH THE
** INCLUSION OF THE ABOVE COPYRIGHT NOTICE. THIS SOFTWARE OR ANY OTHER
** COPIES THEREOF MAY NOT BE PROVIDED OR OTHERWISE MADE AVAILABLE TO ANY
** OTHER PERSON. NO TITLE TO AND OWNERSHIP OF THE SOFTWARE IS HEREBY
** TRANSFERRED.
**
** THE INFORMATION IN THIS SOFTWARE IS SUBJECT TO CHANGE WITHOUT NOTICE
** AND SHOULD NOT BE CONSTRUED AS A COMMITMENT BY DIGITAL EQUIPMENT
** CORPORATION.
**
** DIGITAL ASSUMES NO RESPONSIBILITY FOR THE USE OR RELIABILITY OF ITS
** SOFTWARE ON EQUIPMENT WHICH IS NOT SUPPLIED BY DIGITAL.
*/
/*
**++
** Facility:
**
** Examples
**
** Version: V1.1
**
** Abstract:
**
** Example of working with RMS calls from C
**
** Author:
** Steve Hoffman (XDELTA::HOFFMAN)
**
** Creation Date: 1-Jan-1990
**
** Modification History:
** Hoffman 15-Oct-1994 Updates for DEC C
**--
*/
/*
// RMS_EXAMPLES.C
//
// Program displays some RMS calls made from the c language. Types out
// the calling process's SYS$LOGIN:LOGIN.COM file to SYS$OUTPUT.
//
// Included is a main and three subroutines. The subroutines open,
// read a record, and close the file. Several hooks, such as the
// use of the NAM block to obtain the specification of the file that
// was actually opened, are included but are not currently used.
//
// To build:
//
// $ CC [/DECC] [/DEBUG/NOOPTIM] RMS_EXAMPLES
// $ LINK [/DEBUG] RMS_EXAMPLES
// $ RUN [/[NO]DEBUG] RMS_EXAMPLES
*/
#include <descrip.h>
#include <lib$routines.h>
#include <rms.h>
#include <starlet.h>
#include <string.h>
#include <ssdef.h>
#include <stdio.h>
#include <stsdef.h>
/*
// RMS_MRS is the maximum record size that can be read (and thus
// displayed) by this program.
*/
#define RMS_MRS 255
/*
// The following is the core data structure for the program.
// The various RMS subroutines all communicate via a pointer
// referencing this struct.
*/
struct RmsFileContext
{
struct FAB fab;
struct RAB rab;
struct NAM nam;
struct XABDAT xabdat;
char rss[NAM$C_MAXRSS];
short max_rec_siz;
char *data_buffer;
};
RmsShowDate( void **CtxArg, char *Subject, void *TimeQuad )
{
int RetStat;
struct dsc$descriptor AsciiDate;
int AsciiDateLen = 23;
struct RmsFileContext *Ctx = *CtxArg;
AsciiDate.dsc$b_class = DSC$K_CLASS_D;
AsciiDate.dsc$b_dtype = DSC$K_DTYPE_T;
AsciiDate.dsc$w_length = 0;
AsciiDate.dsc$a_pointer = NULL;
RetStat = lib$sget1_dd( &AsciiDateLen, &AsciiDate );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
RetStat = sys$asctim ( 0, &AsciiDate, TimeQuad, 0 );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
printf("%s\n", Subject );
RetStat = lib$put_output( &AsciiDate );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
printf("\n" );
RetStat = lib$sfree1_dd( &AsciiDate );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
return SS$_NORMAL;
}
RmsFileOpen( void **CtxArg,
char *FileName, char *DefFileName, int flags, int rss )
{
int RetStat;
struct RmsFileContext *Ctx;
int howbig = sizeof( struct RmsFileContext );
char *CDT = "CDT";
/*
// acquire some space for a Context block.
*/
RetStat = lib$get_vm( &howbig, &Ctx, 0 );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
*CtxArg = (void *) Ctx;
/*
// Fill in the various fields of the Context block.
// -- Builds the File Access Block (FAB), the Record Access
// Block (RAB) and the Name (NAM) Block. Along with some
// other miscellaneous housekeeping stuff.
*/
Ctx->fab = cc$rms_fab;
Ctx->rab = cc$rms_rab;
Ctx->nam = cc$rms_nam;
Ctx->xabdat = cc$rms_xabdat;
Ctx->fab.fab$l_nam = &Ctx->nam;
Ctx->fab.fab$l_fop = FAB$M_NAM;
Ctx->fab.fab$b_fac = FAB$M_GET;
Ctx->fab.fab$l_fna = FileName;
Ctx->fab.fab$b_fns = strlen( FileName );
Ctx->fab.fab$l_dna = DefFileName;
Ctx->fab.fab$b_dns = strlen( DefFileName );
Ctx->rab.rab$l_fab = &Ctx->fab;
Ctx->fab.fab$l_xab = &Ctx->xabdat;
Ctx->nam.nam$b_rss = NAM$C_MAXRSS;
Ctx->nam.nam$l_rsa = Ctx->rss;
Ctx->rab.rab$b_rac = RAB$C_SEQ;
/*
// Attempt to open the file...
*/
RetStat = sys$open( &Ctx->fab, 0, 0 );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
/*
// Show the creation date...
*/
RetStat = RmsShowDate( CtxArg, CDT, &Ctx->xabdat.xab$q_cdt );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
/*
// Allocate a buffer large enough for the biggest record.
*/
RetStat = lib$get_vm( &RMS_MRS, &Ctx->data_buffer, 0 );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
/*
// Attempt to connect the record stream to the file...
*/
RetStat = sys$connect( &Ctx->rab, 0, 0 );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
return RetStat;
}
RmsFileRead( void **CtxArg, char **BufAdr, int *BufLen )
{
int RetStat;
struct RmsFileContext *Ctx = *CtxArg;
Ctx->rab.rab$l_ubf = Ctx->data_buffer;
Ctx->rab.rab$w_usz = RMS_MRS;
RetStat = sys$get( &Ctx->rab, 0, 0 );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
{
*BufLen = (char) 0;
*BufAdr = (char) 0;
return RetStat;
}
*BufAdr = Ctx->rab.rab$l_rbf;
*BufLen = Ctx->rab.rab$w_rsz;
return RetStat;
}
RmsFileClose( void **CtxArg )
{
int RetStat;
struct RmsFileContext *Ctx = *CtxArg;
/*
// Free up the record buffer...
*/
RetStat = lib$free_vm( &RMS_MRS, &Ctx->data_buffer, 0 );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
/*
// Be nice and clean up the record stream...
*/
RetStat = sys$disconnect( &Ctx->rab, 0, 0 );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
/*
// And close the file...
*/
RetStat = sys$close( &Ctx->fab, 0, 0 );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
/*
// And free up the allocated memory...
*/
RetStat = lib$free_vm( &sizeof( struct RmsFileContext ), CtxArg, 0 );
if ( !$VMS_STATUS_SUCCESS( RetStat ) )
return RetStat;
return RetStat;
}
main()
{
int RetStat;
void *Context;
char *BufAdr;
int BufLen;
/*
// Open the file. Minimal checking is performed. Read access only.
*/
RetStat = RmsFileOpen( &Context, "LOGIN", "SYS$LOGIN:.COM", 0, 0 );
/*
// Read the file. Minimal checking is performed.
*/
for (;;)
{
RetStat = RmsFileRead( &Context, &BufAdr, &BufLen );
if ( $VMS_STATUS_SUCCESS( RetStat ) )
printf("%*.*s\n", BufLen, BufLen, BufAdr );
else
break;
}
/*
// Close up shop.
*/
RetStat = RmsFileClose( &Context );
return RetStat;
}
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