This is identical in effect to -e.
It has been "deprecated,"
and its use is
file is a regular
file (not a directory or device
file is not zero size
file is a directory
file is a block
file is a character device
device0="/dev/sda2" # / (root directory)
if [ -b "$device0" ]
echo "$device0 is a block device."
# /dev/sda2 is a block device.
device1="/dev/ttyS1" # PCMCIA modem card.
if [ -c "$device1" ]
echo "$device1 is a character device."
# /dev/ttyS1 is a character device.
file is a pipe
[ -p /dev/fd/0 ] && echo PIPE || echo STDIN
show_input_type "Input" # STDIN
echo "Input" | show_input_type # PIPE
# This example courtesy of Carl Anderson.
file is a symbolic
file is a symbolic link
file is a socket
file (descriptor) is
associated with a terminal device
This test option may be used
to check whether the stdin
[ -t 0 ] or
stdout [ -t 1 ]
in a given script is a terminal.
file has read permission (for the
user running the test)
file has write permission (for the user running
file has execute permission (for the user running
set-group-id (sgid) flag set on file or directory
If a directory has the sgid
flag set, then a file created within that directory belongs
to the group that owns the directory, not necessarily to
the group of the user who created the file. This may be
useful for a directory shared by a workgroup.
set-user-id (suid) flag set on file
A binary owned by root
with set-user-id flag set
runs with root privileges, even
when an ordinary user invokes it.
This is useful for executables (such as
pppd and cdrecord)
that need to access system hardware. Lacking the
suid flag, these binaries could not
be invoked by a non-root user.
-rwsr-xr-t 1 root 178236 Oct 2 2000 /usr/sbin/pppd
A file with the suid
flag set shows an s in its
sticky bit set
Commonly known as the sticky bit,
the save-text-mode flag is a special
type of file permission. If a file has this flag set,
that file will be kept in cache memory, for quicker access.
If set on a directory, it restricts write permission.
Setting the sticky bit adds a t
to the permissions on the file or directory listing.
This restricts altering or deleting specific files
in that directory to the owner of those files.
drwxrwxrwt 7 root 1024 May 19 21:26 tmp/
If a user does not own a directory that has the sticky
bit set, but has write permission in that directory, she
can only delete those files that she owns in it. This
keeps users from inadvertently overwriting or deleting
each other's files in a publicly accessible directory,
such as /tmp.
(The owner of the directory or
root can, of course, delete or
rename files there.)
you are owner of file
group-id of file same as yours
file modified since it was last read
- f1 -nt f2
file f1 is newer than
- f1 -ot f2
file f1 is older than
- f1 -ef f2
files f1 and
f2 are hard links to the same
"not" -- reverses the sense of the
tests above (returns true if condition absent).