Linux-shell test, linux-shell

Linux-shell test, linux-shell

Nature of testing:

Is an operation command

According to $? Return Value to determine whether the condition is true

Operation Specifications:

Format 1: test Condition expression

Format 2: [conditional expressions]

Contact Method for test operation:

Direct root & echo YES judgment result

Usage: [conditional expression] & echo YES

Test example:

[-D "/etc/fstab"] & echo YES

[-D "/boot/fstab"] & echo YES

[-F "/etc/fstab"] & echo YES

[-F "/boot"] & echo YES

Existence and identification:

-E: whether the target exists

-D: whether it is a directory

-F: whether it is a file

Permission Detection:

-R: whether the read permission exists.

-W: whether write permission exists

-X indicates whether the execution permission is exclusive.

Integer comparison:

-Equal = (equal)

-Ne is not equal to (not equal)

-Gt greater than (greater)

-Lt is less than (lesser)

-Ge is greater than or equal to (greater or equal)

-Le is less than or equal to (lesser or equal)

Integer comparison:

[$ (Who | wc-l)-eq 2] & echo YES

[$ USER = "root"] & echo YES