System information

System Monitoring Utilities 41
tux@mercury:~> file /usr/share/man/man1/file.1.gz
/usr/share/man/man1/file.1.gz: gzip compressed data, from Unix, max
compression
tux@mercury:~> file -z /usr/share/man/man1/file.1.gz
/usr/share/man/man1/file.1.gz: troff or preprocessor input text \
(gzip compressed data, from Unix, max compression)
The parameter -i outputs a mime type string rather than the traditional description.
tux@mercury:~> file -i /usr/share/misc/magic
/usr/share/misc/magic: text/plain charset=utf-8
2.8.2 File Systems and Their Usage:
mount, df and du
The command mount shows which file system (device and type) is mounted at which
mount point:
tux@mercury:~> mount
/dev/sda2 on / type ext4 (rw,acl,user_xattr)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
debugfs on /sys/kernel/debug type debugfs (rw)
devtmpfs on /dev type devtmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,mode=1777)
devpts on /dev/pts type devpts (rw,mode=0620,gid=5)
/dev/sda3 on /home type ext3 (rw)
securityfs on /sys/kernel/security type securityfs (rw)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
gvfs-fuse-daemon on /home/tux/.gvfs type fuse.gvfs-fuse-daemon \
(rw,nosuid,nodev,user=tux)
Obtain information about total usage of the file systems with the command df. The
parameter -h (or --human-readable) transforms the output into a form under-
standable for common users.
tux@mercury:~> df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 20G 5,9G 13G 32% /
devtmpfs 1,6G 236K 1,6G 1% /dev
tmpfs 1,6G 668K 1,6G 1% /dev/shm
/dev/sda3 208G 40G 159G 20% /home
Display the total size of all the files in a given directory and its subdirectories with
the command du. The parameter -s suppresses the output of detailed information
and gives only a total for each argument. -h again transforms the output into a hu-
man-readable form: