在csh Shell脚本中读取带有空格的用户输入

发布于 2024-07-17 20:21:53 字数 471 浏览 4 评论 0原文

我有一个脚本，用户应该能够输入带空格的字符串。到目前为止，我已经：

#bin/csh

echo "TEST 1"
echo -n "Input : "
set TEST = $<

echo "Var | " $TEST

set TEST=`echo $TEST`

echo "Var after echo | " $TEST

set TEST=`echo $TEST | sed 's/ /_/g'`

echo "Var after change | " $TEST

如果我在“input”处输入字符串“rr r”，$TEST 将只接受“r”。我希望能够将 $TEST 设置为“rr r”。这可能吗？如果我输入像“1 1 1”这样的字符串，我会收到错误：

set：变量名必须以a开头信。

这是什么原因呢？

原文

I have a script where the user should be able to enter a string with spaces. So far I have:

#bin/csh

echo "TEST 1"
echo -n "Input : "
set TEST = lt;

echo "Var | " $TEST

set TEST=`echo $TEST`

echo "Var after echo | " $TEST

set TEST=`echo $TEST | sed 's/ /_/g'`

echo "Var after change | " $TEST

If I enter the string "r r r" at "input", $TEST would only take "r". I want to be able to set $TEST to "r r r". Is this possible?
If I enter a string like "1 1 1" I get an error:

set: Variable name must begin with a
letter.

What's the reason for this?

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撩心不撩汉 2024-07-24 20:21:53

这是因为您没有在 SET 语句中使用引号。当您输入 "rr r" 作为输入时，两种不同的变体（不带引号和带引号）等效于：

set TEST=lt;    :is equivalent to:  set TEST=r r r
set TEST="lt;"  :is equivalent to:  set TEST="r r r"

第一个只是将 TEST 设置为 " r" 和 r 到 ""（两次！）。第二个将 TEST 设置为 "rr r"。这是因为 csh 允许您执行多项赋值，例如：

set a=1 b=2 c d=4

因此您需要使用 SET 的带引号的变体。检查以下记录以了解其工作原理：

[pax ~]$ set x=lt; ; echo .$x.
hello
.hello.

[pax ~]$ set x="lt;" ; echo $x ; echo .$b.$c.
a b c
.a b c.
b: Undefined variable.

[pax ~]$ set x=lt; ; echo $x ; echo .$b.$c.
a b c
.a.
...

[pax ~]$ set x=lt; ; echo $x ; echo .$b.$c.
a b=7 c=urk!
.a.
.7.urk!.

您收到输入 "1 1 1" 所描述的错误的原因是因为您正在有效执行：

set TEST=1 1 1

和 csh 认为这意味着您要创建设置为 "1" 的变量 TEST，后跟变量 1，这不会t 以字母开头，因此不允许。使用引用的变体，这将变为：

set TEST="1 1 1"

它将执行您所期望的操作。

It's because you're not using quotes in your SET statement. When you enter "r r r" as your input, the two different variants (unquoted and quoted) are equivalent to:

set TEST=lt;    :is equivalent to:  set TEST=r r r
set TEST="lt;"  :is equivalent to:  set TEST="r r r"

The first of those simply sets TEST to "r" and r to "" (twice!). The second sets TEST to "r r r". That's because csh lets you do multiple assignments like:

set a=1 b=2 c d=4

So you need to use the quoted variant of SET. Examine the following transcript to see how it works:

[pax ~]$ set x=lt; ; echo .$x.
hello
.hello.

[pax ~]$ set x="lt;" ; echo $x ; echo .$b.$c.
a b c
.a b c.
b: Undefined variable.

[pax ~]$ set x=lt; ; echo $x ; echo .$b.$c.
a b c
.a.
...

[pax ~]$ set x=lt; ; echo $x ; echo .$b.$c.
a b=7 c=urk!
.a.
.7.urk!.

The reason you're getting the error you describe with input of "1 1 1" is because you're effectively executing:

set TEST=1 1 1

and csh is taking this to mean that you want to create the variable TEST set to "1" followed by the variable 1, which doesn't start with a letter, hence not allowed. With the quoted variant, this becomes: