/*
 * df: yes, this, again, is what you'd expect.
 */
#include <stdio.h>
#include <os2.h>

#define ONEMEG	(1024L*1024L)

unsigned long drivelist;	/* all the active filesystems */
short current;			/* filesystem we're sitting on */

char everything=0;		/* df -a - show used space, too */

extern int getopt();
extern int opterr, optind;
extern char *optarg;


#ifdef __STDC__
void getdrivelist(void);
void showdrivefor(char*, int);
void showalldrives(void);
#else
void getdrivelist();
void showdrivefor();
void showalldrives();
#endif


main(argc, argv)
char **argv;
{
    register i, st;

    getdrivelist();

    while ((st=getopt(argc, argv, "t")) != EOF) {
	switch (st) {
	case 't':   everything=1;
		    break;
	default:    fprintf(stderr, "usage: df [-t] [path ...]\n");
		    exit(1);
	}
    }

    if (everything)
	printf("fs\tkbytes\tused\tavail\tcapacity\n");
    else
	printf("fs\tused\tavail\tcapacity\n");
    
    if (optind >= argc)
	showalldrives();
    else for (i=optind; i<argc; i++)
	showdrivefor(argv[i], 1);
    exit(0);
} /* df */


/*
 * getdrivelist() gets a mask of all the active filesystems on this
 * machine.
 */
void
getdrivelist()
{
    DosQCurDisk(&current, &drivelist);
} /* getdrivelist */


/*
 * showalldrives() shows the space free on each and every drive, except
 * for floppy drives.
 */
void
showalldrives()
{
    char bfr[3];
    register unsigned i;

    strcpy(bfr, "@:");

    for (i=2; i<32; i++)
	if (drivelist & (1<<i)) {
	    bfr[0] = 'A'+i;
	    showdrivefor(bfr, 0);
	}
} /* showalldrives */


/*
 * showdrivefor() shows the space free on the drive containing the given
 * pathname
 */
void
showdrivefor(path, verbose)
char *path;
int verbose;
{
    unsigned short drv;
    long allocated, available;
    register st;
    FSALLOCATE fs;

    strlwr(path);
    if (*path && path[1] == ':') {
	drv = path[0]-'a';
	if (drv < 0 || drv > 31) {
	    fprintf(stderr, "%s - invalid filesystem number\n", path);
	    return;
	}
    }
    else
	drv = current-1;

#if 0   /* mapped devices don't show up in the drivelist */
	/* so this code is - *sigh - commented out */
    if ((drivelist & (1<<drv)) == 0) {
	fprintf(stderr, "%c: - not a mounted filesystem\n", drv+'a');
	return;
    }
#endif

    if ((st=DosQFSInfo(1+drv, 1, (PBYTE)&fs, sizeof fs)) == 0) {
	allocated = (fs.cSectorUnit * fs.cbSector * fs.cUnit) / 1024L;
	available = (fs.cSectorUnit * fs.cbSector * fs.cUnitAvail) / 1024L;

	if (everything)
	    printf("%c:\t%ld\t%ld\t%ld\t%2ld%%\n",
		    'a'+drv, allocated, allocated-available, available,
		    (available*100L)/allocated);
	else
	    printf("%c:\t%ld\t%ld\t%2ld%%\n",
		    'a'+drv, allocated-available, available,
		    (available*100L)/allocated);
    }
    else if (verbose)
	fprintf(stderr, "%c: - can't stat filesystem\n", drv+'a');
} /* showdrivefor */