bash-tutorial

• set -e (exit when cmd return with non 0)

Bash basics

Command line editing

Customize the environment

Basic Shell programming

Flow Control

if condition
then
    statements
[elif condition
    then statements...]
[else
    statements]
fi

conditon: a list of statements rather than usual boolean,Exit statuses are the only things an if construct can test.

• bash provides two ways of testing a variety of conditions.[...],[[...]], word spliting and pathname expansion are not performed on the words within the brackets to the second.
• the spaces after the bracket [ and before the closing ] are required.
• the square brackets []surround expressions that include various types of operators.

  • string comparisons:

    • str1=str2
    • str1!=str2
    • str1<str2 -n str1 ( not null str) -z str1 ( null str, length is 0)

  • file attributes checkinng

for name [in list]
do
    statements that can use $name...
done


case expression in pattern1 )
statements ;; pattern2 )
             statements ;;
      ...
esac


select name [in list]
do
    statements that can use $name...
done

while conditiondo
statements...done

until command; do
    statements...done

Command line options and Typed Variables

I/O and Command Processing

Process Handling

Debug