#pragma prototyped
#include <ast.h>
char*
strtape(register const char* s, register char** e)
{
int mtunit = '0';
int mtdensity = 0;
char mtrewind[2];
char mtbehavior[2];
static char tapefile[sizeof("/dev/Xrmt/123456789")];
mtrewind[0] = mtrewind[1] = mtbehavior[0] = mtbehavior[1] = 0;
for (;;)
{
switch (*s)
{
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
mtunit = *s++;
continue;
case 'b':
case 'v':
mtbehavior[0] = *s++;
continue;
case 'l':
case 'm':
case 'h':
case 'u':
case 'c':
mtdensity = *s++;
continue;
case 'n':
mtrewind[0] = *s++;
continue;
}
break;
}
if (e) *e = (char*)s;
if (!access("/dev/rmt/.", F_OK))
{
if (!mtdensity) mtdensity = 'm';
sfsprintf(tapefile, sizeof(tapefile), "/dev/rmt/ctape%c%s", mtunit, mtrewind);
if (!access(tapefile, F_OK)) return(tapefile);
for (;;)
{
sfsprintf(tapefile, sizeof(tapefile), "/dev/rmt/%c%c%s%s", mtunit, mtdensity, mtbehavior, mtrewind);
if (!access(tapefile, F_OK)) return(tapefile);
if (!mtbehavior[0]) break;
mtbehavior[0] = 0;
}
}
else if (!access("/dev/nst0", F_OK))
{
sfsprintf(tapefile, sizeof(tapefile), "/dev/%sst%c", mtrewind, mtunit);
}
else if (!access("/dev/nrmt0", F_OK))
{
switch (mtdensity)
{
case 'l':
mtunit = '0';
break;
case 'm':
mtunit = '1';
break;
case 'h':
mtunit = '2';
break;
}
sfsprintf(tapefile, sizeof(tapefile), "/dev/%srmt%c", mtrewind, mtunit);
}
else
{
mtunit -= '0';
switch (mtdensity)
{
case 'l':
break;
case 'h':
mtunit |= 020;
break;
default:
mtunit |= 010;
break;
}
switch (mtrewind[0])
{
case 'n':
mtunit |= 040;
break;
}
sfsprintf(tapefile, sizeof(tapefile), "/dev/rmt%d", mtunit);
}
return(tapefile);
}