new@udel.edu (Darren New) (10/13/89)
I'm trying to get the name of the device ("DF0:") given the name of
the volume ("Empty"). I'm sure that SOME bit of software knows how to
do this, but I sure can't figure it out. Right now, I'm running thru
the device list until I find the volume node with the right name.
Then I look at node->dn_Task->mp_SigTask->tc_Node.ln_Name. This has
two problems: 1) It seems like the wrong way of doing it. 2) It does
not seem to work for non-mounted devices; i.e., for floppy drives and
such. AmigaDOS obviously does this somehow, but I don't know how.
Can somebody give me a clue? -- Darrencmcmanis%pepper@Sun.COM (Chuck McManis) (10/14/89)
In article <1484@nigel.udel.EDU> new@udel.edu (Darren New) writes: >I'm trying to get the name of the device ("DF0:") given the name of >the volume ("Empty"). ... > ... AmigaDOS obviously does this somehow, but I don't know how. >Can somebody give me a clue? -- Darren A Clue : #include <libraries/dosextens.h> #include <libraries/filehandler.h> struct FileLock *fl; long lock; struct DeviceList *dl; struct DeviceNode *dn; char DeviceName[80]; struct MsgPort *ourtask; lock = Lock("Empty:"); if (!lock) /* No mounted device has an empty volume in it, NOTE: This will generate a requester "please put Empty: in any drive." */ fl = (struct FileLock *)BADDR(lock); dl = (struct DeviceList*)BADDR(fl->fl_Volume); ourtask = dl->dl_Task; /* Now this works, but I don't know if CBM will guarantee it to continue to work. DeviceNodes are always added to the head of the list. So your volume node will always be in front of the device node for the device it is mounted on. */ Forbid(); /* Watch out for changes */ for (dn = (struct DeviceNode *)(BADDR(dl->dl_Next)); dn; dn = (struct DeviceNode *)(BADDR(dn->dn_Next))) { if (dn->dn_Type != DLT_DEVICE) continue; if (dn->dn_Task == ourtask) { strcpy(DeviceName, (char *)(BADDR(dn->dn_Name))+1); break; } } Permit(); printf("That volume is on device %s. \n", DeviceName); --Chuck McManis uucp: {anywhere}!sun!cmcmanis BIX: cmcmanis ARPAnet: cmcmanis@sun.com These opinions are my own and no one elses, but you knew that didn't you. "If I were driving a Macintosh, I'd have to stop before I could turn the wheel."
new@udel.edu (Darren New) (10/17/89)
Ok, another question about AmigaDOS: Is it possible to force the file-system(s) to write out their buffered data? In my program, I write a (sometimes) large file (>400K) and then inhibit the filesystem in order to read bitmaps, etc. Right now I just Delay(300) or so to let the FS finish flushing bitmaps and such. However, this seems like a bad way of doing it, especially since it is possible that the FS won't get a chance to run due to other procs running at a higher priority. There are packets for "ACTION_DISKCHANGE" but I think that these are obsolete. The Inhibit packet seems to cause troubles if DoIO()'ed while the bitmaps are bad. I think I remember experimenting and finding that C:DiskChange will screw up a disk if issued right after writing to a disk, which leads me to believe there is no good way to do it right. Right now, the Delay() seems to be OK, but I'm interested in knowing if there is a better way. Thanks!!! -- Darren