Change df percentage calculation to match posix, spotted by Roy Tam.

diff --git a/toys/posix/df.c b/toys/posix/df.c
index adde58c..0625946 100644 (file)
--- a/toys/posix/df.c
+++ b/toys/posix/df.c
@@ -49,8 +49,7 @@ GLOBALS(
 static void show_mt(struct mtab_list *mt)
 {
        int len;
-       long size, used, avail, percent;
-       uint64_t block;
+       uint64_t size, used, avail, percent, block;
        char *device;
 
        // Return if it wasn't found (should never happen, but with /etc/mtab...)
@@ -72,13 +71,15 @@ static void show_mt(struct mtab_list *mt)
        // Figure out how much total/used/free space this filesystem has,
        // forcing 64-bit math because filesystems are big now.
        block = mt->statvfs.f_bsize ? mt->statvfs.f_bsize : 1;
-       size = (long)((block * mt->statvfs.f_blocks) / TT.units);
-       used = (long)((block * (mt->statvfs.f_blocks-mt->statvfs.f_bfree))
-                       / TT.units);
-       avail = (long)((block
-                               * (getuid() ? mt->statvfs.f_bavail : mt->statvfs.f_bfree))
-                       / TT.units);
-       percent = size ? 100-(long)((100*(uint64_t)avail)/size) : 0;
+       size = (block * mt->statvfs.f_blocks) / TT.units;
+       used = (block * (mt->statvfs.f_blocks-mt->statvfs.f_bfree)) / TT.units;
+       avail = (block * (getuid() ? mt->statvfs.f_bavail : mt->statvfs.f_bfree))
+                       / TT.units;
+       if (!(used+avail)) percent = 0;
+       else {
+               percent = (used*100)/(used+avail);
+               if (used*100 != percent*(used+avail)) percent++;
+       }
 
        device = *mt->device == '/' ? realpath(mt->device, NULL) : NULL;
        if (!device) device = mt->device;