squashfs-info is a dummy squashfs superblock informations dumper "à la tune2fs -l" which work with squashfs images or block devices.
The squashfs-tools doesn't seems to currently provide a way to get all this informations in raw.
This tool is particularly useful to know the real bytes size used by the filesystem, even if the tool unsquashfs -s provides a way to display the superblock informations, it only gives a rounded value of the bytes used which is sometime not enough.
# squashfs-info /path/to/image.squashfs
s_magic: 1936814952
inodes: 10091
mkfs_time: 1457453227
block_size: 131072
fragments: 552
compresultsion: 3
block_log: 17
flags: 704
no_ids: 4
s_major: 4
s_minor: 0
root_inode: 8162970095
bytes_used: 151622805
id_table_start: 151622797
xattr_id_table_start: 18446744073709551615
inode_table_start: 151363862
directory_table_start: 151489418
fragment_table_start: 151592532
lookup_table_start: 151622699
# squashfs-info /dev/mmcblk0p1 | awk '/^bytes_used.*/ {print $2}'
151622805