saj@iuvax.UUCP (02/15/84)
#N:iuvax:11700007:000:2452
iuvax!apratt Jan 9 04:23:00 1984
/** program in Lattice C for MS-DOS to change the volume label of a disk.
Written by Allan Pratt (Collins Box 170, Indiana University, Bloomington,
Indiana, 47406) at ...decvax!ihnp4!iuvax!apratt POSTED TO USENET 1/9/84
USAGE:
A>LABEL text [drive]
The first eleven characters of "text" are made into the volume label
of the disk in drive "drive". If the drive specification is omitted,
the default drive is assumed.
**/
#define XFCB_PREFIX 0xff /* prefix for extended FCBs */
#define LABEL_ATTRIB 0x08 /* label attribute bit */
#define CLOSE_FILE 0x10 /* bdos fn # to close a file */
#define CREATE_FILE 0x16 /* bdos fn # to create a file */
#define RENAME_FILE 0x17 /* bdos fn # to rename a file */
char xfcb[48]; /* buffer for the xfcb itself */
main(argc,argv)
int argc;
char *argv[];
{
char *fcb;
char *c;
int d = 0;
int i;
xfcb[0] = XFCB_PREFIX; /* says this is an extended fcb */
xfcb[6] = LABEL_ATTRIB; /* says this is the volume label */
/* all other bytes of the prefix are zero */
if(argc == 1 || argc > 3) { /* wrong # of params */
printf("label: newlabel [d]\n");
exit();
}
if(argc == 3) { /* determine drive number (to d) */
if (*argv[2] >= 'A' && *argv[2] <= 'Z')
d = *argv[2] - 'A' + 1;
else if (*argv[2] >= 'a' && *argv[2] <= 'z')
d = *argv[2] - 'a' + 1;
else {
printf("label: invalid drive specifier\n");
exit();
}
}
xfcb[7] = d; /* put the drive specifier in the fcb */
/* delete the label if there is one */
for(i=1;i<12;i++) xfcb[7+i]='?'; /* wildcard matches any label */
for(c=argv[1], i=0;i<11;i++) { /* fill the secondary part with the */
if(*c != '\0') xfcb[0x18+i] = *c++; /* new label name */
else xfcb[0x18+i] = ' ';
}
/* the following attempts to rename any file ("????????.???") which
has the LABEL attribute set, to the new label (from the argument).
If that fails, the XFCB is re-worked, so that the new label is in
the normal filename position, and this file (again with the LABEL
attribute) is created. If THAT fails, an error is reported. */
if(bdos(RENAME_FILE,xfcb) & 0xff) { /* attempt a RENAME. */
/* if that fails, move the filename and CREATE */
for(i=0; i<11; i++) /* move the new name into the normal */
xfcb[8+i] = xfcb[0x18+i]; /* filename spot */
if(bdos(CREATE_FILE,xfcb) & 0xff)
printf("label: cannot create new label.\n");
else bdos(CLOSE_FILE,xfcb);
}
}