2019獨角獸企業重金招聘Python工程師標準>>>

首先，新建如下文件demo_file

THIS LINE IS THE 1ST UPPER CASE LINE IN THIS FILE. this line is the 1st lower case line in this file. This Line Has All Its First Character Of The Word With Upper Case.Two lines above this line is empty. And this is the last line.

1 在單個文件中搜索指定字符串

語法：grep "literal_string" filename

$ grep "this" demo_file this line is the 1st lower case line in this file. Two lines above this line is empty. And this is the last line.

2 在多個文件中搜索指定字符串

語法：grep "string" FILE_PATTERN

$cp demo_file demo_file1 $grep "this" demo_*#結果如下 demo_file:this line is the 1st lower case line in this file. demo_file:Two lines above this line is empty. demo_file:And this is the last line. demo_file1:this line is the 1st lower case line in this file. demo_file1:Two lines above this line is empty. demo_file1:And this is the last line. 3 用grep -i忽略大小寫

語法：grep -i "string" FILE

$grep -i "the" demo_file THIS LINE IS THE 1ST UPPER CASE LINE IN THIS FILE. this line is the 1st lower case line in this file. This Line Has All Its First Character Of The Word With Upper Case. And this is the last line. 4 匹配正則表達式

語法：grep "REGEX" filename

$ grep "lines.*empty" demo_file Two lines above this line is empty.

補充一點正則：

? ? ?前面的字段出現0或1次

* ? ?前面的字段出現0或多次

+ ? ?前面的字段出現1或多次

{n} ?前面的字段出現n次

{n,} ?前面的字段出現n或者更多次

{,m} ?前面的字段最多出現m次

{n,m} 前面的字段至少出現n次，最多出現m次

5 完整匹配，忽略字串

語法：grep -w "word" FILENAME

$grep -i "is" demo_file #除匹配is之外，還會匹配his this等 THIS LINE IS THE 1ST UPPER CASE LINE IN THIS FILE. this line is the 1st lower case line in this file. This Line Has All Its First Character Of The Word With Upper Case. Two lines above this line is empty. And this is the last line. 為防止這個現象，用-w

$ grep -iw "is" demo_file THIS LINE IS THE 1ST UPPER CASE LINE IN THIS FILE. this line is the 1st lower case line in this file. Two lines above this line is empty. And this is the last line. 6 查看匹配行的前、后和周圍（after/behind/around）

先新建demo_text

4. Vim Word NavigationYou may want to do several navigation in relation to the words, such as:* e - go to the end of the current word.* E - go to the end of the current WORD.* b - go to the previous (before) word.* B - go to the previous (before) WORD.* w - go to the next word.* W - go to the next WORD.WORD - WORD consists of a sequence of non-blank characters, separated with white space. word - word consists of a sequence of letters, digits and underscores.Example to show the difference between WORD and word* 192.168.1.1 - single WORD* 192.168.1.1 - seven words. 6.1 顯示后N行

語法：grep -A <N> "string" FILENAME

$ grep -A 3 -i "example" demo_text Example to show the difference between WORD and word* 192.168.1.1 - single WORD * 192.168.1.1 - seven words. 6.2 顯示前N行

語法：grep -B <N> "string" FILENAME

$ grep -B 2 "single WORD" demo_text Example to show the difference between WORD and word* 192.168.1.1 - single WORD 6.3 顯示周圍的行

直接上例子

$ grep -C 2 "Example" demo_text word - word consists of a sequence of letters, digits and underscores.Example to show the difference between WORD and word* 192.168.1.1 - single WORD 7 高亮顯示

export GREP_OPTIONS='--color=auto' GREP_COLOR='1;32' 搜索關鍵字，匹配之后會顯示綠色。

如果不想高亮顯示，把auto改成none即可。

8 遞歸查找

語法：grep -r "string" .

會遍歷指定目錄下所有文件及子目錄下所有文件。

9 用-v顯示不匹配的行

語法：grep -v "string" FILENAME

下面的例子會匹配所有不包含go的行。

$grep -v "go" demo_txt 4. Vim Word NavigationYou may want to do several navigation in relation to the words, such as:WORD - WORD consists of a sequence of non-blank characters, separated with white space. word - word consists of a sequence of letters, digits and underscores.Example to show the difference between WORD and word* 192.168.1.1 - single WORD * 192.168.1.1 - seven words. 10 顯示不匹配所有規則的行

$ cat test-file.txt a b c d$ grep -v -e "a" -e "b" -e "c" test-file.txt d 11 計算匹配行數

語法：grep -c "pattern" filename

和-v連用就是計算不匹配的行數

12 只顯示匹配的文件名

語法：grep -l "pattern" file*

注意：-l是小寫的L

$ grep -l this demo_* demo_file demo_file1 13 只顯示匹配的字符串（使用正則的時候特別有用）

$ grep -o "is.*line" demo_file is line is the 1st lower case line is line is is the last line 14 顯示匹配的位置

$ cat temp-file.txt 12345 12345$ grep -o -b "3" temp-file.txt 2:3 8:3 15 顯示行號

$ grep -n "go" demo_text 5: * e - go to the end of the current word. 6: * E - go to the end of the current WORD. 7: * b - go to the previous (before) word. 8: * B - go to the previous (before) WORD. 9: * w - go to the next word. 10: * W - go to the next WORD.

轉載于:https://my.oschina.net/csensix/blog/134846

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