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，我想像这样设置通用通知处理程序调用：

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

notificator.sh 内容：

#!/bin/sh
echo $3

得到如下输出：

"There were apples and oranges in the basket"

有可能吗？怎么做？如果它是内置的 sh 解决方案，我会更喜欢。 我实际上是在尝试通过 curl post 参数将结果字符串 ($3) 作为消息发送给电报机器人，但试图简化这种情况。

Answer 1

通过对您的$3 进行一些更改，我们可以轻松完成这项工作。

首先，让我们定义$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

注意事项：

1. $(1) 尝试运行名为 1 的命令，甚至在脚本运行之前可能会生成错误。请改用${var}。

2. 为了让这个方法起作用，我们需要重命名$3 中的变量。

3. envsubst 是 GNU gettext-base 软件包的一部分，应该在 Linux 发行版中默认可用。

向Charles Duffy 致敬。

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：

$ 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 here-doc：

$ 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

另类

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这个脚本，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