Awk - 如何提高正則表達式？

Question

我有一個文件：

@Book{gjn2011ske, 
    author = {Grzegorz J. Nalepa}, 
    title = {Semantic Knowledge Engineering. A Rule-Based Approach}, 
    publisher = {Wydawnictwa AGH}, 
    year =  2011, 
    address = {Krak\'ow} 
} 

@article{gjn2010jucs, 
    Author = {Grzegorz J. Nalepa}, 
    Journal = {Journal of Universal Computer Science}, 
    Number = 7, 
    Pages = {1006-1023}, 
    Title = {Collective Knowledge Engineering with Semantic Wikis}, 
    Volume = 16, 
    Year =  2010 
} 

我想提高正則表達式，只有刪除的第一道防線。 備註：記錄分隔符RS="}\n"不能更改。

我想：

awk 'BEGIN{ RS="}\n" } {gsub(/@.*,/,"") ; print }' file 

我想打印結果：

author = {Grzegorz J. Nalepa}, 
    title = {Semantic Knowledge Engineering. A Rule-Based Approach}, 
    publisher = {Wydawnictwa AGH}, 
    year =  2011, 
    address = {Krak\'ow} 

    Author = {Grzegorz J. Nalepa}, 
    Journal = {Journal of Universal Computer Science}, 
    Number = 7, 
    Pages = {1006-1023}, 
    Title = {Collective Knowledge Engineering with Semantic Wikis}, 
    Volume = 16, 
    Year =  2010 

謝謝您的幫助。

編輯：

我提出的解決方案：

awk 'BEGIN{ RS="}\n" }{sub(",","@"); sub(/@.*@/,""); print }' file 

Answer 1

很難完成你想要與指定RS設置什麼（因爲address = {Krak\'ow}有結束一個額外的記錄）。我寧願與：

awk '$0 !~ "^@" && $0 !~ "^} *$" { print }' FILE 

查看它in action here。

編輯我不知道爲什麼它必須與正則表達式解決方案，請你解釋一下嗎？

反正，但它使用正則表達式（一個或多個）其他（working, see here）解決方案，而不是你期待：的那些

awk 'BEGIN{ RS="}\n" } 
{ 
    split($0,a,"\n") 
    for (e=1;e<=length(a);e++) { 
     if (a[e] ~ "{" && a[e] !~ "}") { 
      sub("$","}",a[e]) 
     } 
     if (a[e] ~ "=") { print a[e] } 
    } 
    printf("\n") 
}' INPUTFILE 

多個，以更簡單的正則表達式，但它失敗，並「address」行作爲最後}將與您RS被刪除，它會顯示最終} ...

awk 'BEGIN{ RS="}\n" } 
{ 
    sub("@[^,]\+,","") 
    print $0 
}' INPUTFILE 

Answer 2

的一種方式，而無需使用正則表達式。將字段分隔符設置爲換行符，現在每個註冊鍵都將是一個字段。就這樣，遍歷每個字段並打印那些不與@開始：

awk ' 
    BEGIN { 
     RS="}\n"; 
     FS=OFS="\n"; 
    } 
    { 
     for (i=1; i<=NF; i++) { 
      if (substr($i, 1, 1) != "@") { 
       printf "%s%s", $i, (i == NF) ? RS : OFS; 
      } 
     } 
    } 
' file 

輸出：

author = {Grzegorz J. Nalepa}, 
title = {Semantic Knowledge Engineering. A Rule-Based Approach}, 
publisher = {Wydawnictwa AGH}, 
year =  2011, 
address = {Krak\'ow} 

Author = {Grzegorz J. Nalepa}, 
Journal = {Journal of Universal Computer Science}, 
Number = 7, 
Pages = {1006-1023}, 
Title = {Collective Knowledge Engineering with Semantic Wikis}, 
Volume = 16, 
Year =  2010 

Answer 3

我會用GNU sed做到這一點：

sed '/^@/,/^}$/ { //d }' file.txt 

結果：

author = {Grzegorz J. Nalepa}, 
    title = {Semantic Knowledge Engineering. A Rule-Based Approach}, 
    publisher = {Wydawnictwa AGH}, 
    year =  2011, 
    address = {Krak\'ow} 

    Author = {Grzegorz J. Nalepa}, 
    Journal = {Journal of Universal Computer Science}, 
    Number = 7, 
    Pages = {1006-1023}, 
    Title = {Collective Knowledge Engineering with Semantic Wikis}, 
    Volume = 16, 
    Year =  2010 

請注意，您可以使用-i標誌進行就地更改（即，覆蓋文件內容），您可以使用-s標誌對多個文件進行更改。例如：

sed -s -i '/^@/,/^}$/ { //d }' *.txt 

Answer 4

awk '{if($0!~/@/&&$0!~/^}/)print}' temp 

如下測試：

> awk '{if($0!~/@/&&$0!~/^}/)print}' temp 
    author =  {Grzegorz J. Nalepa}, 
    title =  {Semantic Knowledge Engineering. A Rule-Based Approach}, 
    publisher = {Wydawnictwa AGH}, 
    year =   2011, 
    address =  {Krak\'ow} 

    Author =  {Grzegorz J. Nalepa}, 
    Journal =  {Journal of Universal Computer Science}, 
    Number =  7, 
    Pages =  {1006-1023}, 
    Title =  {Collective Knowledge Engineering with Semantic Wikis}, 
    Volume =  16, 
    Year =   2010 
>