[-FLnq
]
[-f format | -l | r | s | x
]
[-t timefmt
]
[file ...
]
readlink
[-n
]
[file ...
]
DESCRIPTION
The
utility displays information about the file pointed to by
file
Read, write or execute permissions of the named file are not required, but
all directories listed in the path name leading to the file must be
searchable.
If no argument is given,
displays information about the file descriptor for standard input.
When invoked as
readlink
only the target of the symbolic link is printed.
If the given argument is not a symbolic link,
readlink
will print nothing and exit with an error.
The information displayed is obtained by calling
lstat(2)
with the given argument and evaluating the returned structure.
The options are as follows:
-F
As in
ls(1),
display a slash
(`/'
)
immediately after each pathname that is a directory,
an asterisk
(`*'
)
after each that is executable,
an at sign
(`@'
)
after each symbolic link,
a percent sign
(`%'
)
after each whiteout,
an equal sign
(`='
)
after each socket,
and a vertical bar
(`|'
)
after each that is a FIFO.
The use of
-F
implies
-l
-L
Use
stat(2)
instead of
lstat(2).
The information reported by
will refer to the target of
file
if file is a symbolic link, and not to
file
itself.
-n
Do not force a newline to appear at the end of each piece of output.
-q
Suppress failure messages if calls to
stat(2)
or
lstat(2)
fail.
When run as
readlink
error messages are automatically suppressed.
-f format
Display information using the specified format.
See the
Sx FORMATS
section for a description of valid formats.
-l
Display output in
ls -lT
format.
-r
Display raw information.
That is, for all the fields in the
Vt stat
structure,
display the raw, numerical value (for example, times in seconds since the
epoch, etc.).
-s
Display information in
``shell output''
suitable for initializing variables.
-x
Display information in a more verbose way as known from some
Linux
distributions.
-t timefmt
Display timestamps using the specified format.
This format is
passed directly to
strftime(3).
Formats
Format strings are similar to
printf(3)
formats in that they start with
%
are then followed by a sequence of formatting characters, and end in
a character that selects the field of the
Vt struct stat
which is to be formatted.
If the
%
is immediately followed by one of
n , t , %
or
@
then a newline character, a tab character, a percent character,
or the current file number is printed, otherwise the string is
examined for the following:
Any of the following optional flags:
#
Selects an alternate output form for octal and hexadecimal output.
Non-zero octal output will have a leading zero, and non-zero
hexadecimal output will have
``0x
''
prepended to it.
+
Asserts that a sign indicating whether a number is positive or negative
should always be printed.
Non-negative numbers are not usually printed
with a sign.
-
Aligns string output to the left of the field, instead of to the right.
0
Sets the fill character for left padding to the
`0'
character, instead of a space.
space
Reserves a space at the front of non-negative signed output fields.
A
`+
'
overrides a space if both are used.
Then the following fields:
size
An optional decimal digit string specifying the minimum field width.
prec
An optional precision composed of a decimal point
`.
'
and a decimal digit string that indicates the maximum string length,
the number of digits to appear after the decimal point in floating point
output, or the minimum number of digits to appear in numeric output.
fmt
An optional output format specifier which is one of
D , O , U , X , F
or
S
These represent signed decimal output, octal output, unsigned decimal
output, hexadecimal output, floating point output, and string output,
respectively.
Some output formats do not apply to all fields.
Floating point output only applies to
Vt timespec
fields (the
a , m
and
c
fields).
The special output specifier
S
may be used to indicate that the output, if
applicable, should be in string format.
May be used in combination with:
Insert a
`` -Gt]
''
into the output.
Note that the default output format
for
Y
is a string, but if specified explicitly, these four characters are
prepended.
sub
An optional sub field specifier (high, middle, low).
Only applies to
the
p , d , r
and
T
output formats.
It can be one of the following:
H
``High''
[em]
specifies the major number for devices from
r
or
d
the
``user''
bits for permissions from the string form of
p
the file
``type''
bits from the numeric forms of
p
and the long output form of
T
L
``Low''
[em]
specifies the minor number for devices from
r
or
d
the
``other''
bits for permissions from the string form of
p
the
``user''
``group''
and
``other''
bits from the numeric forms of
p
and the
ls -F
style output character for file type when used with
T
(the use of
L
for this is optional).
M
``Middle''
[em]
specifies the
``group''
bits for permissions from the
string output form of
p
or the
``suid''
``sgid''
and
``sticky''
bits for the numeric forms of
p
datum
A required field specifier, being one of the following:
d
Device upon which
file
resides.
i
file 's
inode number.
p
File type and permissions.
l
Number of hard links to
file
u , g
User ID and group ID of
file 's
owner.
r
Device number for character and block device special files.
a , m , c , B
The time
file
was last accessed or modified, of when the inode was last changed, or
the birth time of the inode.
z
The size of
file
in bytes.
b
Number of blocks allocated for
file
k
Optimal file system I/O operation block size.
f
User defined flags for
file
v
Inode generation number.
The following four field specifiers are not drawn directly from the
data in
Vt struct stat ,
but are:
N
The name of the file.
T
The file type, either as in
ls -F
or in a more descriptive form if the
sub
field specifier
H
is given.
Y
The target of a symbolic link.
Z
Expands to
``major,minor''
from the
rdev
field for character or block
special devices and gives size output for all others.
Only the
%
and the field specifier are required.
Most field specifiers default to
U
as an output form, with the
exception of
p
which defaults to
Oa , m
and
c
which default to
D
and
Y , T
and
N
which default to
S
EXIT STATUS
Ex -std stat readlink
EXAMPLES
Given a symbolic link
foo
that points from
/tmp/foo
to
/
you would use
as follows:
In order to get a list of file types including files pointed to if the
file is a symbolic link, you could use the following format:
$ stat -f "%N: %HT%SY" /tmp/*
/tmp/bar: Symbolic Link -Gt] /tmp/foo
/tmp/output25568: Regular File
/tmp/blah: Directory
/tmp/foo: Symbolic Link -Gt] /
In order to get a list of the devices, their types and the major and minor
device numbers, formatted with tabs and linebreaks, you could use the
following format:
