grep查看匹配行的上下行

轉載自:http://www.wenzizone.com/2012/01/06/grep_lines_before_and_after_matched_line.html

grep是一個在文件中查找匹配字符串很有幫助的命令。指到現在，我才知道如何使用grep查看匹配字串的上下行內容。

讓我們看一個例子

View Code TEXT

ALICE was beginning to get
very tired of sitting by
her sister on the bank
and of having nothing to do:
once or twice she had peeped
into the book her sister was reading,
but it had no pictures or conversations in it,
"and what is the use of a book," thought Alice,
"without pictures or conversations?'

如果我們現在要搜索帶"bank”的行，我們應該這樣寫

# grep bank test.txt

然後我們會得到

her sister on the bank

如果我們現在想要得到這行，和這行前面的一行，我們應該這樣寫

# grep -B1 bank test.txt

得到的結果是這樣的

very tired of sitting by
her sister on the bank

如果我們要得到包含"bank”的行和其後面的兩行，我們應該這樣寫

# grep -A2 bank test.txt

這樣得到的結果是這樣的

her sister on the bank
and of having nothing to do:
once or twice she had peeped

是不是很方便，當然這兩個參數還可以同時使用。至於例子，這裏就不寫了，留着讀者自己去探索吧。

原文可以參考：http://www.jansipke.nl/grep-lines-before-and-after-matched-line

© 2012, 深夜的蚊子. 版權所有. 如轉載，請註明：轉載自 蚊子空間站[http://www.wenzizone.com]