linux - bash 脚本在失败时创建环回(使用对话框)

Question

我正在编写一个脚本，使用对话框来提示用户提出问题等。其中一个步骤是运行一个命令来生成一些信息。我有一个 if 语句以防它失败，我想做的是，以防它无法让用户重新运行它。对如何去做有点迷茫。

脚本本身

#!/bin/bash

#Generating UID

UID_GREP=${UID_GREP=dialog}
$UID_GREP --title "Appliance Imaging Script" --clear \
    --yesno  "Begin Generate UID for Appliance:" 10 30
    case $? in 
    0)  
      #uid generate script
      /usr/share/bin/create >/tmp/appliance_run.log 2>&1
      ;;  
    1)  
      clear
      echo "exiting"
      exit;;
    255)
      clear
      echo "ESC Pressed... Exiting"
      exit;; 
      esac

 #if Generation of UID fails
   if [ $? != 0 ] ; then
      UID_FAIL=${UID_FAIL=dialog}
      $UID_FAIL --title "UID Genenration failed" --clear \
          --yesno "UID failed to genenerate, would you like to try again" 10 30
          case $? in
    0)  
       #loopback to $UID_GREP

      ;;  
    1)  
      clear
      echo "exiting"
      exit;;
    255)
      clear
      echo "ESC Pressed... Exiting"
      exit;;
      esac

 fi

所以基本上，它说“#loopback to $UID_GREP”我想要它，如果选择是则循环回到 UID_GREP 对话框屏幕。

谢谢。

Answer 1

基本上，您应该做的是为您的应用程序创建一个“主要功能”，基本上是一个循环，它将控制应用程序流程。然后将所有对话框分离到单独的功能。并考虑在适当的情况下将实际操作分离到一个单独的函数中。

#!/bin/bash

# Variable that holds information whether we have generated the UID.
uid_generated=0
loop_count=0    

generate_uid() {
    loop_count=$(( $loop_count + 1 )) #This can be used to check how many times we have failed
    echo "generating UI, execution $loop_count" >> log.txt #For testing purposes
    /usr/share/bin/create >/tmp/appliance_run.log 2>&1

    # Check our result
    if [[ $? -eq 0 ]]; then
        uid_generated=1
    fi

}

initial_dialog() {
    UID_GREP=${UID_GREP=dialog}
    $UID_GREP --title "Appliance Imaging Script" --clear \
    --yesno  "Begin Generate UID for Appliance:" 10 30
    case $? in
    0)
        #uid generate script
        generate_uid
    ;;
    1)
        clear
        echo "exiting"
        exit
    ;;
    255)
        clear
        echo "ESC Pressed... Exiting"
        exit
    ;;
    esac
}

check_result() {
    #if Generation of UID fails
    if [ $? != 0 ] ; then
        UID_FAIL=${UID_FAIL=dialog}
        $UID_FAIL --title "UID Genenration failed" --clear \
        --yesno "UID failed to genenerate, would you like to try again" 10 30

        case $? in
        0)
            #loopback to $UID_GREP
            generate_uid
            ;;
        1)
            clear
            echo "exiting"
            exit
            ;;
        255)
            clear
            echo "ESC Pressed... Exiting"
            exit
            ;;
        esac
    fi
}

# First, show the initial dialog
initial_dialog

# Then we enter our application loop, this might not be exactly what you want, but idea is
# to have variables that control the execution states.
# So you could have eternal while here as well, and other variables define which screen
# should be shown at what time, but to show that this is correct, I do this
while [ $uid_generated -eq 0 ]
do
    generate_uid

    # Consider showing some other screen, or other information in this dialog
    # For example informing user that "we have failed once, and re-generating etc"
    check_result
done

echo "UID generation done" #This will end the program

这只是一个示例，但它确实有效。您可以从 log.txt 中查看您执行了多少次 uid 生成。我保留了与您的格式相似的格式，以便您看起来很熟悉并且可以看到不同之处，但您可能希望有更多的外部变量来控制应用程序流程。

请注意，您不再需要在检查结果中检查失败代码，因为错误检查是在 generate_uid 函数中完成的。该功能纯粹是为了通知用户它失败了。但同样，我没有修改它以保持您的原始内容不变。

但我建议将应用程序逻辑与 UI 逻辑分开。