shell脚本编程-结构化命令2-for命令

    for val in list; do
        commands
    done

    $cat test
    #!/bin/bash
    # basic for command
    for test in A B C; do
        echo the next val is $test
    done
    $./test
    the next val is A
    the next val is B
    the next val is C

　　 $cat test
    #!/bin/bash
    # using a variable to hold the list
    list="A B C"
    list=$list" D"
    for test in $list; do
        echo the next val is $test
    done
    $./test
    the next val is A
    the next val is B
    the next val is C
    the next val is D

    $cat test
    #!/bin/bash
    # reading value from a file
    file="alphabet"
    for test in `cat $file`; do
        echo the next val is $test
    done
    $./test
    the next val is A
    the next val is B
    the next val is C

    IFS.OLD=$IFS
    IFS=$‘\n‘
    <use the new IFS value in code>
    IFS=$IFS.OLD

    $cat test
    #!/bin/bash
    #iterate through all the files in a directory
    for file in /home/test/* ; do
        if [ -d "$file" ]; then
            echo "$file is a directory"
        elif [ -f "$file" ]; then
            echo "$file is a file"
        fi
    done