Lưu ý: Bản dịch của mục này hiện đang được kiểm tra chất lượng, vì vậy một số nội dung tạm thời chỉ hiển thị bằng tiếng Anh.
Mục từ này chưa được dịch sang ngôn ngữ của bạn, vì vậy nội dung gốc được hiển thị bên dưới.
metacharacter
This term is primarily used in the technical registers of computer science, specifically within the context of regular expressions and shell scripting. It describes a symbol that triggers a specific functional operation rather than being treated as a literal piece of text. For example, while a period usually ends a sentence, as a metacharacter in a regex pattern, it matches any single character.
Users should distinguish between the metacharacter itself and the literal character it represents. To treat a metacharacter as a literal character, one must typically use an escape sequence, such as a backslash, to neutralize its special functional power.
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Ví dụ
The asterisk is a common metacharacter used for wildcard searches.
You need to escape the metacharacter if you want to search for the literal symbol.
Wait, did you forget that the period is a metacharacter in regular expressions?
The interpreter treats the dollar sign as a metacharacter to denote the end of a line.
I wonder why this specific metacharacter is causing the script to crash.
Each metacharacter has a predefined function within the parsing engine.
Just use a backslash to neutralize the metacharacter.
The documentation lists every available metacharacter for this language.