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grep命令最經常使用的功能總結

搜索功能 track rac 多重 hat 文件名 info args read

1. grep最簡單的用法,匹配一個詞:grep word filename

2. 能夠從多個文件裏匹配:grep word filename1 filenam2 filename3

3. 能夠使用正則表達式匹配:grep -E pattern f1 f2 f3...

4. 能夠使用-o僅僅打印匹配的字符,例如以下所看到的:

[email protected]:command$ echo this is a line. | grep -E -o "[a-z]*\."
line.
5. 打印除匹配行之外的其它行,使用-v

[email protected]
:command$ echo -e "1\n2\n3\n4" | grep -v -E "[1-2]" 3 4

6. 統計匹配字符串的行數。使用-c

[email protected]:command$ echo -e "1111\n2222" | grep -E "[1-2]" -c
2

7. 假設我們統計字符串模式匹配的次數。能夠結合-o和-c。例如以下:

[email protected]:command$ echo -e "1111\n2222" | grep -o -E "[1-2]"  | wc -l
8

8. 假設須要顯示行號,能夠打開-n,例如以下:

[email protected]:command$ echo -e "1111\n2222\n33333\n44444" | grep -n -E "3"
3:33333

9. -b選項能夠打印出匹配的字符串想對於其所在的行起始位置的偏移量(從0開始)。通常配合-o使用,例如以下:

[email protected]:command$ echo "0123456789" | grep -b -o 4
4:4

10. 當字符串在多個文件裏匹配時。-l選項將僅僅打印文件名稱


11. -L與-l相對。僅僅打印不匹配的文件名稱

[email protected]
/* */:command$ cat test1.txt linux is fun [email protected]:command$ cat test2.txt a very popular os, linux [email protected]:command$ cat test3.txt what the fxxk [email protected]:command$ grep -l linux test1.txt test2.txt test3.txt test1.txt test2.txt [email protected]:command$ grep -L linux test1.txt test2.txt test3.txt test3.txt
12. 打開遞歸搜索功能

[email protected]:command$ grep -n -R linux . 
./test2.txt:5:linux
./test1.txt:1:linux

13. 忽略大寫和小寫:-i

[email protected]:command$ echo "HELLO WORLD" | grep -i "hello"
HELLO WORLD

14. 匹配多個字符串模式

[email protected]:command$ echo "This is a line." | grep -e "This" -e "is" -e "line" -o
This
is
line

15. 用單獨的文件提供匹配樣式,每一個匹配的樣式作為一行,例如以下例所看到的:

[email protected]:command$ cat pattern.txt
1$
2
3
[email protected]:command$ cat num.txt 
1
2
3
4
5
6
7
8
9
10
[email protected]:command$ grep -f pattern.txt num.txt 
1
2
3

16. 打印匹配行上下文信息,使用 -A n打印匹配行及其後n行信息。使用-B n打印匹配行及其前n行信息。使用 -C n。打印匹配行及其前後n行信息。假設有多重匹配,將使用--隔離。

示比例如以下:

[email protected]:command$ seq 1 10 | grep 5 -A 3
5
6
7
8
[email protected]:command$ seq 1 10 | grep 5 -B 3
2
3
4
5
[email protected]:command$ seq 1 10 | grep 5 -C 3
2
3
4
5
6
7
8
[email protected]:command$ echo -e "a\nb\nc\nd\na\nb\nc\nd\n" | grep a -A 2
a
b
c
--
a
b
c

17. 使用-q進入靜默模式,該模式下。grep命令執行目的不過執行一個條件測試。通常在腳本中使用。通過檢查其返回值進行下一步操作。示比例如以下:

[email protected]:command$ cat tmp.txt
hello
world
[email protected]:command$ cat tmp.csh
#!/bin/bash
if [ $# -ne 2 ]; then
	echo "Usage: $0 match_pattern file_name"
	exit
fi
match=$1
file=$2
grep -q $match $file
if [ $?

-ne 0 ]; then echo "$match not exist in $file" else echo "$match exist in $file" fi [email protected]:command$ ./tmp.csh hello tmp.txt hello exist in tmp.txt


18. -Z選項在輸出匹配文件名稱時將以/0結尾配合xargs -0能夠發揮非常多作用,比如刪除匹配某個模式的文件例如以下:

[email protected]:command$ ls -llrt
total 28
-rw-rw-r-- 1 lichao lichao  13 Nov  1 20:38 test1.txt
-rw-rw-r-- 1 lichao lichao  27 Nov  1 20:39 test2.txt
-rw-rw-r-- 1 lichao lichao  14 Nov  1 20:39 test3.txt
-rw-rw-r-- 1 lichao lichao  21 Nov  1 20:45 num.txt
-rw-rw-r-- 1 lichao lichao   7 Nov  1 20:45 pattern.txt
-rw-rw-r-- 1 lichao lichao  12 Nov  1 21:25 tmp.txt
-rwxr-xr-x 1 lichao lichao 217 Nov  1 21:27 tmp.csh
[email protected]:command$ cat test1.txt
linux
is
fun
[email protected]:command$ cat test2.txt
a 
very
popular 
os,
linux
[email protected]:command$ grep "linux" * -lZ | xargs -0 rm
[email protected]:command$ ls
num.txt  pattern.txt  test3.txt  tmp.csh  tmp.txt
以上命令將包括linux字符串的test1.txt和test2.txt刪除。


19. 排除/包含文件或者文件夾:1)--include *{.c,.cpp} 僅僅在文件夾中搜索.c和.cpp文件;2)--exclude "README" 排除全部README文件 3) --include-dir 僅在某些文件夾中搜索 4) --exclude-dir 排除某些文件夾 5) --exclude-from FILE 從文件FILE中讀取須要排除的文件列表

[email protected]:test$ ls
dir1  dir2  exclude.config  test1.txt  test2.doc  test3.word
[email protected]:test$ cat test1.txt 
linux 
is 
fun
[email protected]:test$ cat test2.doc 
wonderful 
os,
linux
[email protected]:test$ cat test3.word 
wonderful 
os,
linux
[email protected]:test$ ls dir1/
test1.txt  test2.doc  test3.word
[email protected]:test$ ls dir2/
test1.txt  test2.doc  test3.word
[email protected]:test$ cat exclude.config 
*.txt
[email protected]:test$ grep "linux" -R -n . 
./test2.doc:3:linux
./test3.word:3:linux
./test1.txt:1:linux 
./dir2/test2.doc:3:linux
./dir2/test3.word:3:linux
./dir2/test1.txt:1:linux 
./dir1/test2.doc:3:linux
./dir1/test3.word:3:linux
./dir1/test1.txt:1:linux 
[email protected]:test$ grep "linux" -R -n . --include *.txt --include *.doc
./test2.doc:3:linux
./test1.txt:1:linux 
./dir2/test2.doc:3:linux
./dir2/test1.txt:1:linux 
./dir1/test2.doc:3:linux
./dir1/test1.txt:1:linux 
[email protected]:test$ grep "linux" -R -n . --exclude *.txt --eclude *.doc
grep: unrecognized option ‘--eclude‘
Usage: grep [OPTION]... PATTERN [FILE]...
Try ‘grep --help‘ for more information.
[email protected]:test$ grep "linux" -R -n . --exclude *.txt --exclude *.doc
./test3.word:3:linux
./dir2/test3.word:3:linux
./dir1/test3.word:3:linux
[email protected]:test$ grep "linux" -R -n . --exclude-dir dir1
./test2.doc:3:linux
./test3.word:3:linux
./test1.txt:1:linux 
./dir2/test2.doc:3:linux
./dir2/test3.word:3:linux
./dir2/test1.txt:1:linux 
[email protected]:test$ grep "linux" -R -n . --exclude-dir dir1 --exclude-dir dir2
./test2.doc:3:linux
./test3.word:3:linux
./test1.txt:1:linux 
[email protected]:test$ grep "linux" -R -n . --exclude-from exclude.config 
./test2.doc:3:linux
./test3.word:3:linux
./dir2/test2.doc:3:linux
./dir2/test3.word:3:linux
./dir1/test2.doc:3:linux
./dir1/test3.word:3:linux

已上即為grep經常使用的選項。


註意:轉載請註明出處。





grep命令最經常使用的功能總結