命令：grep
用途：搜索文本
用法: grep match_pattern filename
1.支持多种匹配格式
-E:支持正则表达式，等同egrep
yang@Ubuntu:~$ echo "this is a line." | grep -E "[a-z]\." this is a line. yang@Ubuntu:~$ echo "this is a line." | egrep "[a-z]\." this is a line.
-i:忽略样式中的大小写
yang@Ubuntu:~$ echo -e "this is a line.\nthis is another LINE." | grep -i "[a-z]\." this is a line. this is another LINE.
-e:匹配多个样式
yang@Ubuntu:~$ echo -e "this is a line.\nthis is another LINE." | grep -e "[a-z]\." -e "[A-Z]\." this is a line. this is another LINE.
-f:从文件中读取样式，逐行写下需要匹配的样式
yang@Ubuntu:~$ cat pat_file [a-z]\. [A-Z]\. yang@Ubuntu:~$ echo -e "this is a line.\nthis is another LINE." | grep -f pat_file this is a line. this is another LINE.
-v：打印除match_pattern之外的所有行
yang@Ubuntu:~$ echo -e "this is a line.\nthis is another LINE.\nthis is the third line." | grep -v "third" this is a line. this is another LINE.
2.输出多种形式
-c:统计包含匹配字符串的行个数
yang@Ubuntu:~$ echo -e "this is a line.\nthis is another LINE.\nthis is the third line." | grep -c "[a-z]\." 2
-o:只输出文件中匹配到的文本部分
yang@Ubuntu:~$ echo -e "this is a line.\nthis is another LINE.\nthis is the third line." | grep -o "[a-z]\." e. e.
统计包含匹配字符串的个数
yang@Ubuntu:~$ echo -e "this is a line.\nthis is another LINE.\nthis is the third line." | grep -o "[a-z]\." | wc -l 2
-b：输出行距离起始的位置（-b -o：匹配字符串距离起始的位置）
yang@Ubuntu:~$ echo -e "this is a line.\nthis is another LINE.\nthis is the third line." | grep -b "[a-z]\." 0:this is a line. 38:this is the third line. yang@Ubuntu:~$ echo -e "this is a line.\nthis is another LINE.\nthis is the third line." | grep -b -o "[a-z]\." 13:e. 59:e.
-n:打印出包含匹配字符串所在的行号
yang@Ubuntu:~$ echo -e "this is a line.\nthis is another LINE.\nthis is the third line." | grep -n -e "[a-z]\." 1:this is a line. 3:this is the third line.
-l:输出匹配的文件列表
yang@Ubuntu:~/file$ cat A.txt this is a line. yang@Ubuntu:~/file$ cat B.txt this is a LINE. yang@Ubuntu:~/file$ grep -l "[A-Z]\." A.txt B.txt B.txt
-L:输出不匹配的文件列表
yang@Ubuntu:~/file$ grep -L "[A-Z]\." A.txt B.txt A.txt
-A:匹配结果之后的行
-B:匹配结果之前的行
-C:匹配结果之前和之后的行
yang@Ubuntu:~/file$ grep -e "[A-Z]\." file1.txt -C 1 this is a line. this is a second LINE. this is the third line.
-q 返回是否包含，如果包含返回0，没有返回非0
yang@Ubuntu:~/file$ grep -q -e "[0-9]\." file1.txt yang@Ubuntu:~/file$ echo $? 1 yang@Ubuntu:~/file$ grep -q -e "[a-z]\." file1.txt yang@Ubuntu:~/file$ echo $? 0
3.支持多种文件选项
支持多文件
yang@Ubuntu:~$ cat file1.txt this is a line. this is a second LINE. this is the third line. yang@Ubuntu:~$ cat file2.txt this is a line. this is a second LINE. this is the third line. yang@Ubuntu:~$ grep "[A-Z]\." file1.txt file2.txt file1.txt:this is a second LINE. file2.txt:this is a second LINE.
-R：递归搜索文件
yang@Ubuntu:~/file$ tree . ├── exclude │ └── file3.txt ├── file1.txt └── include └── file2.log 2 directories, 3 files yang@Ubuntu:~/file$ grep "[A-Z]\." . -R ./file1.txt:this is a second LINE. ./include/file2.log:this is a second LINE. ./exclude/file3.txt:this is a second LINE.
--include:只在目录中递归包含的文件
yang@Ubuntu:~/file$ grep "[A-Z]\." . -R --include *.log ./include/file2.log:this is a second LINE.
--exclude:在目录中排除的文件之外递归
yang@Ubuntu:~/file$ grep "[A-Z]\." . -R --exclude *.log ./file1.txt:this is a second LINE. ./exclude/file3.txt:this is a second LINE.
--excelude-dir:排除目录
yang@Ubuntu:~/file$ grep "[A-Z]\." . -R --exclude-dir "exclude" ./file1.txt:this is a second LINE. ./include/file2.log:this is a second LINE.