Shell Basics Learning (v) Test command

1. Numerical test

Parameters	Description
-eq	Equals is True
-gt	is greater than true
-lt	is less than true
-nq	Not equal to True
-ge	Greater than or equal to true
-le	is less than or equal to true

Example:

num1=num2=if  test $[num1] eq $[num2]then      Echo  ' two numbers equal 'else       echo' two numbers are unequal ' fi

Output: Two numbers equal

2. String Test

Parameters	Description
=	Equals is True
！ =	Not equal to True
-Z	String length is zero for true
-N	String length is not 0 bit true

Example:

string1='liupf'string2='liupf'if test string1=string2then    echo' two strings equal 'Else     echo' two strings unequal 'fi

Output: Two strings equal

3. File test

Parameters	Description
-E File name	File exists as true
-W file name	File exists and can be written as true
-R file name	File exists and can be read as true
-X file name	File exists and can be executed as true
-S file name	File exists and has at least one string
-D file name	For a directory to be true
-F file name	For an ordinary file to be true
-C file name	True if the file exists and is a character-specific file
-B file Name	True if the file exists and is a block special file

Example:

　　

CD/binif test-e./bashthen    echo' file already exists! ' Else    Echo ' file does not exist! ' fi
Output: File already exists

Shell Basics Learning (v) Test command