如何從文件中提取最後一塊

我有一個包含很多這樣的塊文件：如何從文件中提取最後一塊

==9673== 
==9673== HEAP SUMMARY: 
==9673==  in use at exit: 0 bytes in 0 blocks 
==9673== total heap usage: 75,308 allocs, 75,308 frees, 7,099,382 bytes allocated 
==9673== 
==9673== All heap blocks were freed -- no leaks are possible 
==9673== 
==9673== For counts of detected and suppressed errors, rerun with: -v 
==9673== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0) 
.... 
.... 
.... 
.... 

==9655== 
==9655== HEAP SUMMARY: 
==9655==  in use at exit: 0 bytes in 0 blocks 
==9655== total heap usage: 75,308 allocs, 75,308 frees, 7,099,382 bytes allocated 
==9655== 
==9655== All heap blocks were freed -- no leaks are possible 
==9655== 
==9655== For counts of detected and suppressed errors, rerun with: -v 
==9655== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0) 

.... 
.... 
.... 

==9699== 
==9699== HEAP SUMMARY: 
==9699==  in use at exit: 0 bytes in 0 blocks 
==9699== total heap usage: 75,308 allocs, 75,308 frees, 7,099,382 bytes allocated 
==9699== 
==9699== All heap blocks were freed -- no leaks are possible 
==9699== 
==9699== For counts of detected and suppressed errors, rerun with: -v 
==9699== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

我要提取的最後一個塊開始行：

==XXXX== HEAP SUMMARY:

所以在我的示例我想只提取最後一個區塊：

==9699== HEAP SUMMARY: 
==9699==  in use at exit: 0 bytes in 0 blocks 
==9699== total heap usage: 75,308 allocs, 75,308 frees, 7,099,382 bytes allocated 
==9699== 
==9699== All heap blocks were freed -- no leaks are possible 
==9699== 
==9699== For counts of detected and suppressed errors, rerun with: -v 
==9699== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

我該怎麼用bash做到這一點？

來源

2016-12-13 MOHAMED

[編輯]您輸入擺脫所有的'...'S和使之成爲具體的，可測試的例子。塊之間的文本與塊一樣重要。例如，如果在每個塊之間確實存在空白行，那麼您所需要的只是'awk -v RS ='{s = $ 0} END {print s}'文件'，並且如果每個塊都是8行所有你需要的是「尾-8文件」，但如果其中任何一個真的是你的輸入格式化或不。 –

使用grep -zoP和負前瞻正則表達式：

grep -zoP '==\w{4}== HEAP SUMMARY:(?![\s\S]*==\w{4}== HEAP SUMMARY:)[\s\S]*\z' file 

==9699== HEAP SUMMARY: 
==9699==  in use at exit: 0 bytes in 0 blocks 
==9699== total heap usage: 75,308 allocs, 75,308 frees, 7,099,382 bytes allocated 
==9699== 
==9699== All heap blocks were freed -- no leaks are possible 
==9699== 
==9699== For counts of detected and suppressed errors, rerun with: -v 
==9699== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

-z會把文件終止，而不是新的行數據爲空值終止
(?![\s\S]*==\w{4}== HEAP SUMMARY:)是負先行斷言我們沒有的另一個實例在下面的文件中也是一樣。

RegEx Demo

來源

2016-12-13 15:27:02 anubhava

如果你有tac，這可能是最簡單的

$ tac file | awk '1; /==....== HEAP SUMMARY/{exit}' | tac

來源

2016-12-13 15:29:27 karakfa

如果你知道塊總是9行代碼，你可以簡單地使用tail：

tail -n9 file

來源

2016-12-13 15:32:57 kalj

With sed：

$ sed -n '/HEAP SUMMARY/{:a;/ERROR SUMMARY/bb;N;ba;:b;$p;d}' infile 
==9699== HEAP SUMMARY: 
==9699==  in use at exit: 0 bytes in 0 blocks 
==9699== total heap usage: 75,308 allocs, 75,308 frees, 7,099,382 bytes allocated 
==9699== 
==9699== All heap blocks were freed -- no leaks are possible 
==9699== 
==9699== For counts of detected and suppressed errors, rerun with: -v 
==9699== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

這裏是如何工作的：

sed -n '     # Do not print lines at end of each cycle 
    /HEAP SUMMARY/ {  # If line matches "HEAP SUMMARY" 
     :a     # Label to jump back to 
     /ERROR SUMMARY/bb # If line matches "ERROR SUMMARY", jump to :b 
     N     # Append next line to pattern space 
     ba     # Jump to :a 
     :b     # Label to jump forward to 
     $p     # If we are on the last line, print pattern space 
     d     # Delete pattern space 
    } 
' infile

每次遇到這種HEAP SUMMARY，它讀取所有行到下一個ERROR SUMMARY入模式空間。然後，它檢查是否已經到達最後一行;如果是，則打印模式空間，否則將被刪除。

來源

2016-12-13 15:56:08

如果文件的最後一行也有塊號，這將讓該塊數快速（無整個文件的閱覽找哪個號碼是）：

n="$(tail -n1 infile | awk '{print $1}')"

然後，我們可以選擇有這樣的塊數結束了所有行：

tac infile | awk -vn="$n" '!($1~n){exit};1'| tac

來源

2016-12-13 17:39:17 sorontar

這可能會爲你工作（GNU SED）：

sed '/HEAP SUMMARY:/h;//!H;$!d;x' file

遇到HEAP SUMMARY:時，用當前行替換保持空間（HS）中的任何內容。對於任何其他模式，將該行附加到HS。當模式空間（PS）與HS交換並打印出PS時，刪除除最後一行外的所有行。

來源

2016-12-13 20:07:13 potong

使用數據的前面，一個id /組號數：

id=$(tail -n1 file | grep -Po '(?<=\=\=)[0-9]*') && grep "$id" file |tail -n+2

來源

2016-12-13 22:14:42

如何從文件中提取最後一塊

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