如何插入作为参数发送的字符串？

Question

我对文件系统的访问权限有限，并且我想设置通用通知处理程序调用，如下所示：

notificator.sh "apples" "oranges" "There were $(1) and $(2) in the basket"

notificator.sh内容：

#!/bin/sh
echo $3

并得到如下输出：

"There were apples and oranges in the basket"

这可能吗？如何实现？我更喜欢它是一个内置的 sh 解决方案。我实际上正在尝试通过curl post param将结果字符串（$3）作为消息发送给电报机器人，但试图简化情况。

Answer 1

通过对您的 进行一些更改$3，我们可以轻松地完成这项工作。

首先，我们来定义$1、$2和$3：

$ set -- "apples" "oranges" 'There were ${one} and ${two} in the basket'

现在，让我们强制替换为$3：

$ one=$1 two=$2 envsubst <<<"$3"
There were apples and oranges in the basket

笔记：

1. $(1)尝试运行名为1and 的命令可能会在脚本运行之前生成错误。${var}代替使用。

2. 为了让这个方法发挥作用，我们需要重命名$3.

3. envsubst是 GNUgettext-base软件包的一部分，默认情况下 Linux 发行版应该可用。

向查尔斯·达菲致敬。

以脚本形式

考虑这个脚本：

$ cat script.sh
#!/bin/sh
echo "$3" | one=$1 two=$2 envsubst

我们可以执行上面的命令：

$ sh script.sh "apples" "oranges" 'There were ${one} and ${two} in the basket'
There were apples and oranges in the basket

作为替代方案（再次向Charles Duffy致敬），我们可以使用此处文档：

$ cat script2.sh
#!/bin/sh
one=$1 two=$2 envsubst <<EOF
$3
EOF

运行这个版本：

$ sh script2.sh "apples" "oranges" 'There were ${one} and ${two} in the basket'
There were apples and oranges in the basket

选择

以下脚本不需要envsubst：

$ cat script3.sh
#!/bin/sh
echo "$3" | awk '{gsub(/\$\{1\}/, a); gsub(/\$\{2\}/, b)} 1' a=$1 b=$2

使用我们的参数运行此脚本，我们发现：

$ sh script3.sh "apples" "oranges" 'There were ${1} and ${2} in the basket'
There were apples and oranges in the basket
$ sh script3.sh "apples" "oranges" 'There were ${1} and ${2} in the basket'
There were apples and oranges in the basket