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| -rw-r--r-- | it-it/pcre-it.html.markdown | 13 | ||||
| -rw-r--r-- | pcre.html.markdown | 25 | ||||
| -rw-r--r-- | zh-tw/pcre-tw.html.markdown | 9 |
3 files changed, 31 insertions, 16 deletions
diff --git a/it-it/pcre-it.html.markdown b/it-it/pcre-it.html.markdown index 68233858..704392ef 100644 --- a/it-it/pcre-it.html.markdown +++ b/it-it/pcre-it.html.markdown @@ -11,7 +11,7 @@ lang: it-it Un'espressione regolare (regex o regexp in breve) è una speciale stringa utilizzata per definire un pattern, ad esempio per cercare una sequenza di caratteri; ad esempio, `/^[a-z]+:/` può essere usato per estrarre `http:` -dall'URL `http://github.com/`. +dall'URL `http://github.com/`. PCRE (Perl Compatible Regular Expressions) è una libreria per i regex in C. La sintassi utilizzata per le espressioni è molto simile a quella di Perl, da @@ -19,7 +19,9 @@ cui il nome. Si tratta di una delle sintassi più diffuse per la scrittura di regex. Esistono due tipi di metacaratteri (caratteri con una funzione speciale): + * Caratteri riconosciuti ovunque tranne che nelle parentesi quadre + ``` \ carattere di escape ^ cerca all'inizio della stringa (o della riga, in modalità multiline) @@ -36,16 +38,17 @@ Esistono due tipi di metacaratteri (caratteri con una funzione speciale): ``` * Caratteri riconosciuti nelle parentesi quadre + ``` \ carattere di escape ^ nega la classe se è il primo carattere - indica una serie di caratteri [ classe caratteri POSIX (se seguita dalla sintassi POSIX) ] termina la classe caratteri - -``` +``` + +PCRE fornisce inoltre delle classi di caratteri predefinite: -PCRE fornisce inoltre delle classi di caratteri predefinite: ``` \d cifra decimale \D NON cifra decimale @@ -62,9 +65,11 @@ PCRE fornisce inoltre delle classi di caratteri predefinite: ## Esempi Utilizzeremo la seguente stringa per i nostri test: + ``` 66.249.64.13 - - [18/Sep/2004:11:07:48 +1000] "GET /robots.txt HTTP/1.0" 200 468 "-" "Googlebot/2.1" ``` + Si tratta di una riga di log del web server Apache. | Regex | Risultato | Commento | diff --git a/pcre.html.markdown b/pcre.html.markdown index 3e877a35..9e091721 100644 --- a/pcre.html.markdown +++ b/pcre.html.markdown @@ -3,16 +3,18 @@ language: PCRE filename: pcre.txt contributors: - ["Sachin Divekar", "http://github.com/ssd532"] - + --- -A regular expression (regex or regexp for short) is a special text string for describing a search pattern. e.g. to extract domain name from a string we can say `/^[a-z]+:/` and it will match `http:` from `http://github.com/`. +A regular expression (regex or regexp for short) is a special text string for describing a search pattern. e.g. to extract domain name from a string we can say `/^[a-z]+:/` and it will match `http:` from `http://github.com/`. PCRE (Perl Compatible Regular Expressions) is a C library implementing regex. It was written in 1997 when Perl was the de-facto choice for complex text processing tasks. The syntax for patterns used in PCRE closely resembles Perl. PCRE syntax is being used in many big projects including PHP, Apache, R to name a few. There are two different sets of metacharacters: + * Those that are recognized anywhere in the pattern except within square brackets + ``` \ general escape character with several uses ^ assert start of string (or line, in multiline mode) @@ -32,18 +34,19 @@ There are two different sets of metacharacters: ``` * Those that are recognized within square brackets. Outside square brackets. They are also called as character classes. - + ``` - + \ general escape character ^ negate the class, but only if the first character - indicates character range [ POSIX character class (only if followed by POSIX syntax) ] terminates the character class - -``` -PCRE provides some generic character types, also called as character classes. +``` + +PCRE provides some generic character types, also called as character classes. + ``` \d any decimal digit \D any character that is not a decimal digit @@ -59,7 +62,13 @@ PCRE provides some generic character types, also called as character classes. ## Examples -We will test our examples on following string `66.249.64.13 - - [18/Sep/2004:11:07:48 +1000] "GET /robots.txt HTTP/1.0" 200 468 "-" "Googlebot/2.1"`. It is a standard Apache access log. +We will test our examples on the following string: + +``` +66.249.64.13 - - [18/Sep/2004:11:07:48 +1000] "GET /robots.txt HTTP/1.0" 200 468 "-" "Googlebot/2.1" +``` + + It is a standard Apache access log. | Regex | Result | Comment | | :---- | :-------------- | :------ | diff --git a/zh-tw/pcre-tw.html.markdown b/zh-tw/pcre-tw.html.markdown index c9cdc537..5f681d46 100644 --- a/zh-tw/pcre-tw.html.markdown +++ b/zh-tw/pcre-tw.html.markdown @@ -13,7 +13,9 @@ lang: zh-tw 相容Perl正規表達式(Perl Compatible Regular Expressions, PCRE)是一個實作正規表達式的C語言函式庫。此函式庫在1997年被開發出來，在當時面對複雜字串處理時大多會選擇使用Perl。也因為如此，PCRE大多的正規表達式語法都很酷似Perl。PCRE語法被廣泛運用在許多大專案中，包括PHP、Apache、R等。 PCRE中的超字元(metacharacter)主要可以分為以下兩類: + * 在中括號外會被辨識的字元 + ``` \ 通用跳脫字元 ^ 字串開頭 或 行首 @@ -33,18 +35,17 @@ PCRE中的超字元(metacharacter)主要可以分為以下兩類: ``` * 在中括號內會被辨識的超字元，在中括號外會被視為字元集合使用 - + ``` - \ 通用跳脫字元 ^ 非字元集合的字，但只會抓到第一個符合的字元 - 字元範圍 [ POSIX字元集合(若後面接POSIX格式) ] 字元集合定義結束 - -``` +``` PCRE提供了一些通用的字元類型，可被當作字元集合使用 + ``` \d 任何數字字元 \D 任何非數字字元 |