string tcsh 中匹配的字符串/子字符串
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strings / substrings matching in tcsh
提问by MadMacs
I'm struggling trying to use a concise comparison statement to avoid a bunch of "if a = b or a = c or a = d or a = e", etc.
我正在努力尝试使用简洁的比较语句来避免一堆“if a = b or a = c or a = d or a = e”等。
Instead, I'm trying to use regex and pattern matching like you would do in perl.
相反，我正在尝试使用正则表达式和模式匹配，就像您在 perl 中所做的那样。
with
和
set st = "red"
设置 st = "红色"
the line
线
if ($st =~ yellow|blue|red|green)
如果（$st =~黄色|蓝色|红色|绿色）
just doesn't work (if: Expression Syntax.) I tried with quotes, parenthesis, but I never get the expected result, if no error.
只是不起作用（如果：表达式语法。）我尝试使用引号，括号，但如果没有错误，我永远不会得到预期的结果。
is there a way to avoid the heavy construct:
有没有办法避免重构造：
if ($st == yellow) || ($st == blue) || ($st == red) || ($st == green) ?
如果 ($st == 黄色) || ($st == 蓝色) || ($st == 红色) || ($st == 绿色) ?
Or another way to ask the same question: does tcsh allow for something like "if string a contains string b"? I couldn't find any notion of substring in tcsh reference.
或者用另一种方式问同样的问题：tcsh 是否允许诸如“如果字符串 a 包含字符串 b”之类的内容？我在 tcsh 参考中找不到任何子字符串的概念。
Thanks a million!
太感谢了！
回答by Gerrat
I don't know tsch, but looking at the info this page (under Special Characters): http://www.tcsh.org/tcsh.html/Filename_substitution.htmlhttp://www.cs.duke.edu/csl/docs/csh.htmlit appears that you need to surround your colours with braces:
我不知道 tsch，但查看此页面的信息（在特殊字符下）：http://www.tcsh.org/tcsh.html/Filename_substitution.html http://www.cs.duke.edu/csl /docs/csh.html看来你需要用大括号包围你的颜色：
if ($st =~ {yellow,blue,red,green})
回答by Keith Thompson
The thing on the right hand side of the ~=operator is a "glob-pattern", nota regular expression. (For example, in a regexp .matches any character, and .*matches zero or more arbitrary characters; the glob-pattern equivalents are ?and *.)
~=运算符右侧的内容是“全局模式”，而不是正则表达式。（例如，在正则表达式中.匹配任何字符，并.*匹配零个或多个任意字符；glob-pattern 等价物是?和*。）
{...,...,...}is part of the syntax of glob-patterns. man tcshfor a full description.
{...,...,...}是 glob-patterns 语法的一部分。 man tcsh完整的描述。
If you need to match regular expression, you can use the exprcommand; man expror info exprfor details.
如果需要匹配正则表达式，可以使用该expr命令；man expr或info expr了解详情。
