FBKDT

Syntax	FBKDT [(#channel)] or FBKDT (\file)
Location	Level-2 Device Drivers, SMS

It is proposed that this function be used to return the date on which a given file was last backed up. Current versions of SuperBASIC commands, such as COPY and WCOPY do not set the back-up date of the file being copied, although some software will do this, WinBack for example.

The idea of a back-up date is mainly for use in automatic back-up programs which can be told to copy all files on a given medium within certain parameters, namely files which have been altered since a specific date and which have been altered since the last time that they were backed up.

The value returned is the date in QDOS format, ie. the number of seconds since Midnight 1st January 1961 {check this initial date with PRINT DATE$(0)}. This backup time currently needs to be set manually using SET_FBKDT, although it is hoped that future versions of COPY and WCOPY will do so automatically.

If it has not been set, FBKDT will return zero. The default data device and sub-directories are supported, default channel is #3.

Example

The PROCedure below will make an intelligent backup of all files contained in the medium specified by the first parameter to the medium specified in the second parameter, which have been altered since they were last backed up. TinyToolkit’s TCONNECT or DIY-TK’s QLINK is necessary to use this example. This can be used for example by entering the line:

BACKUP flp1_ TO flp2_

Although sub-directories and the default data device are fully supported on the medium being backed-up, the procedures would need modification to enable them to create similar sub-directories on the destination device. The PROCedure makes heavy use of recursive programming, which means that it uses a lot of memory (not all of which is released at the end of the PROCedure). It would need a considerable re-write to be in a form which could be safely compiled.

100 DEFine PROCedure BACKUP (dir1,dir2)
110   LOCal dir1$,dir2$,old_datad$,old_destd$
120   LOCal ERRno,outer,sloop
130   dir1$=PARSTR$(dir1,1):dir2$=PARSTR$(dir2,2)
140   old_datad$=DATAD$:old_destd$=DESTD$
150   DATA_USE '':ERRno=-7
160   REPeat sloop
170     IF FTEST(dir1$)<0
180       dir1$=old_datad$&dir1$
190       IF FTEST(dir1$)<0:PRINT #0,dir1$;' ';:EXIT sloop
200     END IF
210     full_dir$=(dir1$&' ')(1 TO 5):orig_dir$=dir1$
220     IF FTEST(dir2$)<0
230       outer=FOP_NEW(dir2$):IF outer>0:CLOSE #outer
240       IF outer<0
250         dir2$=old_destd$&dir2$
260         IF old_destd$(LEN(old_destd$))<>'_':ERRno= -15:EXIT sloop
270         IF FOP_OVER(dir2$)<0:PRINT #0,dir2$;' ';:EXIT sloop
280       END IF
290     END IF
300     ERRno=0:EXIT sloop
310   END REPeat sloop
320   DATA_USE old_datad$
330   IF ERRno<0:REPORT ERRno:RETurn
340   IF dir2$(LEN(dir2$))<>'_':dir2$=dir2$&'_'
350   main_ch=-1:max_ch=0
360   read_directory dir1$
370   PRINT #0,'Backup complete'
380   FOR i=main_ch TO max_ch:CLOSE #i
390 END DEFine
400 :
410 DEFine PROCedure read_directory(current_dir$)
420   LOCal in_ch,out_ch
430   in_ch=FOPEN('scr_'):IF main_ch=-1:main_ch=in_ch
440   out_ch=FOPEN(pipe_10000):DIR #out_ch,current_dir$
450   TCONNECT #out_ch TO #in_ch
460   CLOSE #out_ch
470   copy_file$ #in_ch,full_dir$,dir2$
480   IF in_ch>max_ch:max_ch=in_ch
490 END DEFine
500 :
510 DEFine PROCedure copy_file$(chan,in$,out$)
520   LOCal files_loop,junk$,outer,test1,test2
530   INPUT #chan,junk$,junk$
540   REPeat files_loop
550     IF EOF(#chan):EXIT files_loop
560     INPUT #chan,in_file$
570     out_file$=out$&in_file$
580     in_file$=in$&in_file$
590     IF LEN(in_file$)>3
600       IF in_file$(LEN(in_file$)-2 TO)=' ->'
610         read_directory in_file$(1 TO LEN(in_file$)-3)
620         NEXT files_loop
630       END IF
640     END IF
650     test1=FBKDT(\in_file$)
660     outer=FOPEN(out_file$)
670     IF outer>0
680       test2=FUPDT(#outer):CLOSE #outer
690     ELSE
700       test2=-7
710     END IF
720     IF test2<test1 OR test1=0
730       PRINT 'Backing-up'!in_file$!'=>'!out_file$
740       DELETE out_file$:COPY in_file$ TO out_file$
750       SET_FBKDT \in_file$,DATE
760     END IF
770   END REPeat files_loop
775   CLOSE#chan
780 END DEFine

CROSS-REFERENCE

FUPDT, FLEN, FTYP, FDAT, FXTRA, FILE_LEN, FILE_LEN, FILE_TYPE, FVERS and FNAME$ return other information about a file.