Conditional judgment in Shell

If

In the

-Z

To

-D

The meaning

2011-09-05 10:30

[-A FILE]

If

FILE

The existence is true.

[-B FILE]

If

FILE

Exists and is a block special file is true.

[-C FILE]

If

FILE

exists and is a word special file is true.

[-D FILE]

If

FILE

exists and is a directory is true.

[-E FILE]

If

FILE

The existence is true.

[-F FILE]

If

FILE

exists and is an ordinary file is true.

[-G FILE]

If

FILE

exists and has been set

SGID

Is true.

[-H FILE]

If

FILE

Is true if it exists and is a symbolic connection.

[-K FILE]

If

FILE

exists and the sticky bit has been set is true.

[-P FILE]

If

FILE

exists and is a name pipe

(F

If

O)

Is true.

[-R FILE]

If

FILE

Is true if it exists and is readable.

[-S FILE]

If

FILE

exists and is not of the size

0

Is true.

[-T FD]

If the file descriptor

Fd

Open and point to a terminal is true.

[-U FILE]

If

FILE

exists and sets the

SUID (set user ID)

Is true.

[-W FILE]

If

FILE

If

FILE

Is true if it exists and is writable.

[-X FILE]

If

FILE

Is true if it exists and is executable.

[-O FILE]

If

FILE

exists and is a valid user

Id

Is true.

[-G FILE]

If

FILE

exists and is valid user group is true.

[-L FILE]

If

FILE

Is true if it exists and is a symbolic connection.

[-N FILE]

If

FILE

Exist

and has been mod

If

IED since it was last read

Is true.

[-S FILE]

If

FILE

exists and is a socket is true.

[File1-nt FILE2]

If

FILE1 have been changed more recently than FILE2,

Or

If

FILE1 exists and FILE2 does not

Is true.

[File1-ot FILE2]

If

FILE1

Than

FILE2

to old

,

Or

FILE2

exists and

FILE1

Is true if it does not exist.

[File1-ef FILE2]

If

FILE1

And

FILE2

Pointing to the same device and node number is true.

[-O optionname]

If

Shell

Options

"Optionname"

It is true to turn on.

[ -

Z string] "string"

is true if the length is zero.

[ -

n string] or [string] "string"

is non-zero in length

Non-zero

Is true.

[STRING1 = = STRING2]

If

2

The same string.

"=" may be used instead of

"= =" for strict POSIX compliance

Is true.

[STRING1! = STRING2]

True if the strings are not equal.

[STRING1 < STRING2]

If

"STRING1" sorts before "STRING2"

Lexicographically in the current locale

Is true.

[STRING1 > STRING2]

If

"STRING1" sorts after "STRING2"

Lexicographically in the current locale

Is true.

[ARG1 OP ARG2] "OP" is one of

-eq,-ne,-lt,-le,-gt Or-ge. These arithmetic

Binary operators return True if "ARG1" is equal to, not equal to, less than, less

than or equal to, greater than

, or greater than or equal to "ARG2", respectively.

"ARG1" and "ARG2" are integers.

Conditional judgment in Shell