如何让我的 bash 脚本打开 cat 进行输入，然后将输入保存到脚本中的变量中

Question

我认为您要求的是不可能的。使用时read，您只能使用非常有限的文本编辑功能，它根本不是为您想要它做的事情而设计的。即使您可以找到允许退格和换行的方法，这仍然是一种非常麻烦的让用户提供输入的方式。期望用户直接在正在运行的程序中输入文本很少是一个好主意。我建议另一种选择：

让你的脚本从命令行读取主题。
让它从输入文件中读取正文。

这样，您的用户就不需要手动输入所有内容，您的脚本可以自动发送多封电子邮件，大大提高了它的实用性，并且您的用户如果输入错误也不需要从头开始。最后，他们可以根据需要格式化电子邮件正文。例如，您可以执行以下操作：

#!/bin/bash
## Parse command line options. 
while getopts ":s:f:" opt; do
  case $opt in
            s)
                subject="$OPTARG"
                ;;
            f)
                file="$OPTARG"
                ## Exit if the file isn't a file or isn't readble               
                if [[ ! -r "$file" && ! -f "$file" ]]; then
                    echo "File doesn't exist or isn't readble"
                        exit
                fi
                ;;
    \?)
      echo "Invalid option: -$OPTARG" >&2;;
  esac
done
## Read the email body
body=$(cat "$file")

## Inform the user. The "\033[1m" starts bold formatting and the
## "\033[0m" ends it. Remove them if you don't want bold. 
echo -e "\033[1mYour message is as follows:\033[0m"
cat<<EoF

From: $USER
To: Administrator
Subject: $subject

$body

------------------
EoF

read -p "Send to Administrator (y/n)?" choice
case "$choice" in
  y|Y ) echo "$body" | mail -s "$subject" [email protected];;
  n|N ) echo "Roger Dodger. Email canceled";;
    * ) echo "invalid";;
esac

然后，您为其提供主题和输入文件。例如，如果您有一个名为的文件，其message内容如下：

$ cat message 
Dear John,

I hope this email finds you well. I am writing to inquire about the
price of the bridge you are selling. I would love to have a bridge
like that in my garden since I think it would make my cows look
larger.

Looking forward to hearing from you,

best,

Jack.

你可以像这样运行脚本：

$ foo.sh -s "about that bridge..." -f message 
Your message is as follows:

From: terdon
To: Administrator
Subject: about that bridge...

Dear John,

I hope this email finds you well. I am writing to inquire about the
price of the bridge you are selling. I would love to have a bridge
like that in my garden since I think it would make my cows look
larger.

Looking forward to hearing from you,

best,

Jack. 

------------------
Send to Administrator (y/n)?

或者，如果您坚持让用户即时编写消息，则可以使用系统上可用的默认编辑器：

#!/bin/bash

clear
echo -e "Please Enter Subject of email:\n "
read subject

## create a temp file
tmpfile=$(mktemp)

cat<<EoF

Press Enter to open an editor where you can write the body of the email.
When finished, save and exit.
EoF
read

## Open the editor
"$EDITOR" "$tmpfile"

## Read the body and delete the tmp file
body=$(cat "$tmpfile")
rm "$tmpfile"
## Inform the user. The "\033[1m" starts bold formatting and the
## "\033[0m" ends it. Remove them if you don't want bold. 
echo -e "\033[1mYour message is as follows:\033[0m"
cat<<EoF

From: $USER
To: Administrator
Subject: $subject

$body
EoF

read -p "Send to Administrator (y/n)?" choice
case "$choice" in
  y|Y ) echo "$body" | mail -s "$subject" [email protected];;
  n|N ) echo "Roger Dodger. Email canceled";;
    * ) echo "invalid";;
esac

最后，如果您坚持要让您和用户的生活变得比本该的更加困难，您可以使用cat > $tmpfile将正文写入 tmpfile，告诉您的用户在写完后点击Ctrl+ ：D

#!/bin/bash

clear
echo -e "Please Enter Subject of email:\n "
read subject

## create a temp file
tmpfile=$(mktemp)
## Enter the body
printf '\nPlease enter the body of the email below. Hit Ctrl+D when done.\n\n'
cat > $tmpfile
body=$(cat "$tmpfile")
rm "$tmpfile"
## Inform the user. The "\033[1m" starts bold formatting and the
## "\033[0m" ends it. Remove them if you don't want bold. 
echo -e "\033[1mYour message is as follows:\033[0m"
cat<<EoF

From: $USER
To: Administrator
Subject: $subject

$body
EoF

read -p "Send to Administrator (y/n)?" choice
case "$choice" in
  y|Y ) echo "$body" | mail -s "$subject" [email protected];;
  n|N ) echo "Roger Dodger. Email canceled";;
    * ) echo "invalid";;
esac

Answer 1