hartkopf@tramp.Colorado.EDU (Jeff Hartkopf) (10/13/89)
I'm attempting to learn how to use GS/OS calls, and have come up with
some questions. Things don't seem to be working the same way as they did
with the ProDOS 16 calls.
For example, to get file info on a file, I did something like
GSString255 s = {13, "/hd/test.file"};
FileInfoRecGS filerec;
filerec.pathname = &s;
filerec.pCount = (word) 2;
GetFileInfoGS(&filerec);
At first I didn't assign anything to the pCount variable and kept
getting errors, so after a little experimentation, I found that 2 seems
to work. But what is the pCount field of most of the GS/OS records for?
When I did the above, I just seemed to get garbage values for the fileType,
access, auxType, createDateTime, modDateTime, etc., fields. What am I doing
wrong? Do any other fields besides pathname and pCount have to be pre-set
before I call GetFileInfoGS()?
Thanks very much for any help.
Jeff Hartkopf
Internet:
hartkopf@tramp.Colorado.EDUfarrier@Apple.COM (Cary Farrier) (10/13/89)
In article <12696@boulder.Colorado.EDU> hartkopf@tramp.Colorado.EDU (Jeff Hartkopf) writes: > >I'm attempting to learn how to use GS/OS calls, and have come up with >some questions. Things don't seem to be working the same way as they did >with the ProDOS 16 calls. > >For example, to get file info on a file, I did something like > [...example deleted...] > >At first I didn't assign anything to the pCount variable and kept >getting errors, so after a little experimentation, I found that 2 seems >to work. But what is the pCount field of most of the GS/OS records for? > >When I did the above, I just seemed to get garbage values for the fileType, >access, auxType, createDateTime, modDateTime, etc., fields. What am I doing >wrong? Do any other fields besides pathname and pCount have to be pre-set >before I call GetFileInfoGS()? The pcount field in the Class 1 GS/OS system calls tells the system how many parameters are in your pblock. The format for the class 1 GET_FILE_INFO call is: $00-$01 pcount $02-$05 input pointer to a class 1 input string containing the pathname $06-$07 access $08-$09 file_type $0A-$0D aux_type ... [and so on...] When you specify a pcount of 2, you are telling the system that you only want to give it the pathname and to receive the file_type. A pcount of 3 will include the aux_type, and so on. Since you only specify a pcount of 2, the FST will not fill in any parameters other than the first two. Note that the pcount does not include pcount itself. Cary Farrier -- +--------------+-------------------------+ | Cary Farrier | farrier@apple.com | +--------------+-------------------------+
dlyons@Apple.COM (David Lyons) (10/14/89)
>In article <12696@boulder.Colorado.EDU> hartkopf@tramp.Colorado.EDU (Jeff Hartkopf) writes: >>I'm attempting to learn how to use GS/OS calls, and have come up with >>some questions. Things don't seem to be working the same way as they did >>with the ProDOS 16 calls. The main reason for this is that the GS/OS (class 1) calls are *not* the same as the ProDOS 16 (class 0) calls. :-) (If they were they same, we wouldn't need two kinds of calls, eh?) >>At first I didn't assign anything to the pCount variable and kept >>getting errors, so after a little experimentation, I found that 2 seems >>to work. But what is the pCount field of most of the GS/OS records for? For GetFileInfoGS, use pCount=12 to get back all the information that the current version of GS/OS can return for that call. BTW, it will probably help a bunch if you buy the GS/OS reference from APDA. Cary Farrier writes: > The pcount field in the Class 1 GS/OS system calls tells the > system how many parameters are in your pblock. The format > for the class 1 GET_FILE_INFO call is: > > $00-$01 pcount > $02-$05 input pointer to a class 1 input string > containing the pathname > $06-$07 access > $08-$09 file_type > $0A-$0D aux_type > ... [and so on...] > > When you specify a pcount of 2, you are telling the system > that you only want to give it the pathname and to receive > the file_type. A pcount of 3 will include the aux_type, and > so on. Since you only specify a pcount of 2, the FST will > not fill in any parameters other than the first two. Note > that the pcount does not include pcount itself. > Looks like 2 will get you only the Access parameter back (the input pathname counts as the first parameter), so 3 will get you the Access and Filetype. -- --Dave Lyons, Apple Computer, Inc. | DAL Systems AppleLink--Apple Edition: DAVE.LYONS | P.O. Box 875 America Online: Dave Lyons | Cupertino, CA 95015-0875 GEnie: D.LYONS2 or DAVE.LYONS CompuServe: 72177,3233 Internet/BITNET: dlyons@apple.com UUCP: ...!ames!apple!dlyons My opinions are my own, not Apple's.