phil@adam.adelaide.edu.au (Phil Kernick) (10/26/90)
If I use the following stub of code:
getinfo()
{
BPTR fred;
struct FileInfoBlock *fib;
lock = Lock("fred", ACCESS_READ);
Examine(lock, fib);
}
I can get information on the file protection from fib->fib_Protection and
date from fib->fib_FileDate (this is from my memory, ie don't tell me that
I have the structure members wrong :-), but how can I set them?
I wan't to know how the programs "protect" from WB 1.3.2 and "touch"
from the SAS C 5.05 work. It would seem that they simply change the
fields that they want in the fib and then write it back. How is this
done? I have the RKM but it is *very* old (only deals with KS 1.1).
Thanks,
Phil.
--
Phil Kernick EMail: phil@adam.adelaide.edu.au
Departmental Engineer Phone: +618 228 5914
Dept. of Psychology Fax: +618 224 0464
University of Adelaide Mail: GPO Box 498 Adelaide SA 5001ken@cbmvax.commodore.com (Ken Farinsky - CATS) (10/26/90)
In article <phil.656904446@adam.adelaide.edu.au> phil@adam.adelaide.edu.au (Phil Kernick) writes: >If I use the following stub of code: > >getinfo() >{ > BPTR fred; > struct FileInfoBlock *fib; > > lock = Lock("fred", ACCESS_READ); > Examine(lock, fib); >} AACK!! You have to allocate the memory for the file info block. something like: if (NULL != (fib = (struct FileInfoBlock *) AllocMem(sizeof(*fib),MEMF_CLEAR | MEMF_PUBLIC))) { /* use the fib here */ FreeMem(fib, sizeof(*fib)); } Note that AllocMem() guarantees longword alignment. Sorry for any errors, I'm doing this from memory. Here's the info on Examine(): SYNOPSIS success = Examine( lock, infoBlock ) D0 D1 D2 BOOL success; struct FileLock *lock; struct FileInfoBlock *infoBlock FUNCTION Examine() fills in information in the FileInfoBlock concerning the file or directory associated with the lock. This information includes the name, size, creation date and whether it is a file or directory. FileInfoBlock must be longword aligned. Examine() gives a return code of zero if it fails. You may make a local copy of the FileInfoBlock, as long as it is never passed back to the operating system. INPUTS lock - BCPL pointer to a lock infoBlock - pointer to a FileInfoBlock (must be longword aligned) OUTPUTS success - boolean -- -- Ken Farinsky - CATS - (215) 431-9421 - Commodore Business Machines uucp: ken@cbmvax.commodore.com or ...{uunet,rutgers}!cbmvax!ken bix: kfarinsky
markv@kuhub.cc.ukans.edu (11/08/90)
In article <15413@cbmvax.commodore.com>, ken@cbmvax.commodore.com (Ken Farinsky - CATS) writes: >> struct FileInfoBlock *fib; >> >> lock = Lock("fred", ACCESS_READ); >> Examine(lock, fib); > AACK!! You have to allocate the memory for the file info block. > something like: > if (NULL != (fib = (struct FileInfoBlock *) > AllocMem(sizeof(*fib),MEMF_CLEAR | MEMF_PUBLIC))) >... Or if you have SAS C 5.1 you can say: struct FileInfoBlock _aligned fib; and use &fib. The _aligned is nice because it eliminates the need for lots of otherwise uneeded Alloc/Free code just so you can get longword alignment. Obviously such a variable can't be auto storage class. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Mark Gooderum Only... \ Good Cheer !!! Academic Computing Services /// \___________________________ University of Kansas /// /| __ _ Bix: markgood \\\ /// /__| |\/| | | _ /_\ makes it Bitnet: MARKV@UKANVAX \/\/ / | | | | |__| / \ possible... Internet: markv@kuhub.cc.ukans.edu ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
walker@unx.sas.com (Doug Walker) (11/08/90)
In article <phil.656904446@adam.adelaide.edu.au> phil@adam.adelaide.edu.au (Phil Kernick) writes: >If I use the following stub of code: > >getinfo() >{ > BPTR fred; > struct FileInfoBlock *fib; > > lock = Lock("fred", ACCESS_READ); > Examine(lock, fib); >} > >I can get information on the file protection from fib->fib_Protection and >date from fib->fib_FileDate (this is from my memory, ie don't tell me that >I have the structure members wrong :-), but how can I set them? This code WILL NOT WORK. You'd better actually allocate the FileInfoBlock, or declare an instance using the __aligned keyword in 5.10 SAS/C: struct FileInfoBlock __aligned fib; lock=Lock... Examine(lock, &fib); or struct FileInfoBlock *fib; fib = (struct FileInfoBlock *)AllocMem(sizeof(struct FileInfoBlock), 0); lock = Lock... Examine(lock, fib); > >I wan't to know how the programs "protect" from WB 1.3.2 and "touch" >from the SAS C 5.05 work. It would seem that they simply change the >fields that they want in the fib and then write it back. How is this >done? I have the RKM but it is *very* old (only deals with KS 1.1). > >Thanks, > >Phil. To set the fields, you have to call the appropriate DOS functions (SetProtection, SetDate) or send DOS packets to the file system instructing it to do this. You can't just 'write back' the FIB. Get a copy of the AmigaDOS programmer's guide for the version of the operating system you are running on and read up on the other DOS calls. Actually, after a quick look at the prototypes in my 1.3 include files, it looks like SetProtection exists in 1.3, but SetFileDate doesn't get added until 2.0. You'll have to look into the DOS packet interface to set the file date under 1.3. Alternatively, you could just open the file for read/write, read a byte, and write it back if you just want to set the file date to the current date like touch. ***** =*|_o_o|\\=====Doug Walker, Software Distiller====== BBS: (919)460-7430 = *|. o.| || 1200/2400/9600 Dual | o |// For all you do, this bug's for you! ====== usenet: ...mcnc!rti!sas!walker plink: dwalker bix: djwalker
aycock@cpsc.ucalgary.ca (aycock) (11/10/90)
Mark Gooderum (markv@kuhub.cc.ukans.edu) writes: | Or if you have SAS C 5.1 you can say: | | struct FileInfoBlock _aligned fib; | | and use &fib. The _aligned is nice because it eliminates the need for | lots of otherwise uneeded Alloc/Free code just so you can get longword | alignment. Or, if you don't have Lattice, or refuse to never ever ever use another of their compilers again, you could use: unsigned char space[sizeof(struct FileInfoBlock) + 4]; struct FileInfoBlock *fib; fib = (struct FileInfoBlock *) (((unsigned long)space+4)&~3); I agree, though, it's much nicer than using AllocMem() and FreeMem(). :ja -- //\|_||\| John D. Aycock aycock@cpsc.ucalgary.ca \/ \/| || | (403) 285-8727
walker@unx.sas.com (Doug Walker) (11/27/90)
>Or if you have SAS C 5.1 you can say: > > struct FileInfoBlock _aligned fib; > >and use &fib. The _aligned is nice because it eliminates the need for >lots of otherwise uneeded Alloc/Free code just so you can get longword >alignment. Obviously such a variable can't be auto storage class. >-- It's __aligned, not _aligned. And the variable CAN be auto storage class, or any other storage class. It can even be a member of a structure - pad bytes will be added to the structure if needed. ***** =*|_o_o|\\=====Doug Walker, Software Distiller====== BBS: (919)460-7430 = *|. o.| || 1200/2400/9600 Dual | o |// For all you do, this bug's for you! ====== usenet: ...mcnc!rti!sas!walker plink: dwalker bix: djwalker
peter@sugar.hackercorp.com (Peter da Silva) (11/28/90)
Re: __aligned in a structure. What if you have a structure with an __aligned member and allocate an instance of this structure on the stack. Does this force the compiler to allocate an __aligned structure or do you have to __align it as well? -- Peter da Silva. `-_-' <peter@sugar.hackercorp.com>.
walker@unx.sas.com (Doug Walker) (11/30/90)
>Or, if you don't have Lattice, or refuse to never ever ever use another of >their compilers again, you could use: A perfect opportunity, you can now use SAS/C instead! Seriously, it sounds to me like you haven't tried the compiler environment in the last couple of years. It's changed a tremendous amount. Come see it in the booth at an AmiExpo sometime. > >unsigned char space[sizeof(struct FileInfoBlock) + 4]; >struct FileInfoBlock *fib; > >fib = (struct FileInfoBlock *) (((unsigned long)space+4)&~3); > Or do this: #define DCL(name, type) char c_##name[sizeof(type)+3];\ type * name = (type *)((((long)c_##name+3)>>2)<<2); DCL(fib, struct FileInfoBlock); Then fib will automagically be initialized to point to an aligned FileInfoBlock. This works for autos, statics or externs, as long as the compiler you are using supports ANSI token pasting (##) which I know SAS/C does and I'm pretty sure Manx does. ***** =*|_o_o|\\=====Doug Walker, Software Distiller====== BBS: (919)460-7430 = *|. o.| || 1200/2400/9600 Dual | o |// For all you do, this bug's for you! ====== usenet: ...mcnc!rti!sas!walker plink: dwalker bix: djwalker
markv@kuhub.cc.ukans.edu (12/06/90)
In article <7155@sugar.hackercorp.com>, peter@sugar.hackercorp.com (Peter da Silva) writes: > Re: __aligned in a structure. > What if you have a structure with an__aligned member and allocate an instance > of this structure on the stack. Does this force the compiler to allocate an > __aligned structure or do you have to __align it as well? You will get an error. You must use a static storage class for an __aligned structure for somewhat obvious reasons. Just like you cant have a __chip object on the stack. > -- > Peter da Silva. `-_-' > <peter@sugar.hackercorp.com>. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Mark Gooderum /\ \ | / H a p p y Academic Computing Services / v\ -- * -- H o l i d a y s ! :-) University of Kansas /v v\ / | \ /// /__v___\ Only /// /| __ _ Bitnet: MARKV@UKANVAX || \\\ /// /__| |\/| | | _ /_\ makes it Internet: markv@kuhub.cc.ukans.edu \/\/ / | | | | |__| / \ possible ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
peter@sugar.hackercorp.com (Peter da Silva) (12/07/90)
In article <27257.275ce563@kuhub.cc.ukans.edu> markv@kuhub.cc.ukans.edu writes: > You will get an error. You must use a static storage class for an > __aligned structure for somewhat obvious reasons. Just like you cant > have a __chip object on the stack. I don't see why you can't have an __aligned structure on the stack... it'd just take an extra instruction on subroutine entry. But that doesn't address the question I asked: that is if you have a structure with an __aligned element is that whole structure forced __aligned: typedef struct { struct FileInfoBlock __aligned fib; blah blah blah; } baz; Now what if you do this: foo() { baz zot; ... } Is this illegal? > > > -- > > Peter da Silva. `-_-' > > <peter@sugar.hackercorp.com>. > -- > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Mark Gooderum /\ \ | / H a p p y > Academic Computing Services / v\ -- * -- H o l i d a y s ! :-) > University of Kansas /v v\ / | \ /// > /__v___\ Only /// /| __ _ > Bitnet: MARKV@UKANVAX || \\\ /// /__| |\/| | | _ /_\ makes it > Internet: markv@kuhub.cc.ukans.edu \/\/ / | | | | |__| / \ possible > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -- Peter da Silva. `-_-' <peter@sugar.hackercorp.com>.