Shell Process Control Statements

First, if

Syntax format: If test-d $arg then ... else ... fi

Variable test statements can be simplified with []. Example: test-d $arg equivalent to [-D $arg]. (Note: "Space" ["Space"-D "space"])

For more test commands see: http://www.cnblogs.com/fangwu/p/8422910.html

1. Sample script code

#!/bin/shif [-D $arg]then    echo "This is a folder" Else    echo "This is not a folder" fi

2. Execute script (parameter is/usr)

[Email protected]]# sh hello.sh/usr

3. Implementation results

This is a folder

Second, if Elif

If [-D $arg 1]then ...    elif [-F $arg 2]then ... else .....    Fi

Logic and logic or (-A: Logic with-o: Logical OR)

If [-D $arg 1-a-D $arg 2]

Shell Process Control Statements