display free disk space

df [-b | -h | -H | -k | -m | -g | -P] [-ailn] [-t] [-T type] [file | filesystem]

Displays statistics about the amount of disk space on the filesystem or on the filesystem where file exists.

If neither file nor filesystem is specified, statistics for all mounted filesystems are displayed (subject to -T).

-a Show all mount points, including those mounted with MNT_IGNORE .
-P supresses inode infomation
-i Include the number of free inodes. default. -P suppresses this .
-b Use 512-byte blocks. override $BLOCKSIZE Default
-k Use Kbyte 1,024-byte blocks, overrides $BLOCKSIZE
-m Use Mbyte 1,048,576-byte blocks.
-g Use Gbyte 1,073,741,824-byte blocks.
-H "Human-readable" output using base 10. suffixes: Byte, Kilobyte, Megabyte, Gigabyte, Terabyte and Petabyte
-h "Human-readable" using base 2 for sizes.

Unaligned, with varying blocksize.

/bin/df -nPH
Filesystem      Size   Used  Avail Capacity  Mounted on
/dev/disk2s1     40G    28G    11G    73%    /
devfs           353k   353k     0B   100%    /dev
/dev/disk0s3    650M   559M    91M    87%    /Volumes/Recovery HD
/dev/disk1s5     37G    11G   8.3G    58%    /Volumes/Photos

-l Only display locally-mounted filesystems. Supresses /dev, /net, /home
-n network volumes ouptput previously obtained statistics for file | filesystem. useful if a filesystem will not provide statistics with a delay.
-T type[,…] Only output information for filesystems of the specified types.
More than one type may be specified in a comma separated list. The list types can be prefixed with no to specify types for which action should not be taken. For example:
df -T nonfs,mfs
lists all filesystems except those of type NFS and MFS.