Linuxshell Script Programming Basics 5--Numeric, string, file status test, ((..)) and [[...]] The use

1. Numerical comparison

! /bin/Bashecho"Enter a score:"Read NUM1if[$num 1-ge the]then Echo"Very Good"elif [$num 1-lt the-A $num 1-ge -]then Echo"Good"ElseEcho" Low"fi

which

-eq equals

-ne Not equal to

-lt less than

-le less than or equal to

-GT Greater than

-ge greater than or equal to

Equal equals not equal does not equal less than greater greater than

Elif is also the else if

-A and

-O OR

2, ((..)) and [[...]] The use

Echo"Enter a score:"Read Num2if(($num 2 >= the) then echo"Very Good"elif [[$num 2-lt the&& $num 2-ge -]]then Echo"Good"ElseEcho" Low"fi

3. String and file status test

#! /bin/Bashecho"enter filename or workname:"Read Name1if[ -z $name 1]then Echo"your enter is null"ExitElse        if[ -F $name 1] then echo"This is a file"Elif [-d $name 1] then echo"This is a workspace"        ElseEcho"Not found file or workspace"Fifi

-Z is an empty string (length of 0) returns True

-N is a non-empty string when returning true

-D is present and is a directory when returning True

-F exists and is normal file returns True

Linuxshell Script Programming Basics 5--Numeric, string, file status test, ((..)) and [[...]] The use