linux grep工作常用

本文主要是工作中grep的常见使用：
1. grep日志统计（单个多个文件）计数
2. grep and or not
3. grep 多个文件匹配查找
4. grep -A -B 关键匹配前后几行的重要信息

grep -c ‘text’ filename(log指定text行数统计)

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工作中我们往往要统计日志中某些字符串（一行行）的统计信息，
一般 grep ‘text’ filename | wc -l
其实： grep -c ‘text’ filename 更简单直接统计行数

$ grep -c "go" demo_text6When you want do find out how many lines that does not match the pattern$ grep -v -c this demo_file4    

grep or 查询

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1. grep ‘pattern1|pattern2’ filename

2. grep -E ‘pattern1|pattern2’ filename

3. egrep ‘pattern1|pattern2’ filename

4. grep -e pattern1 -e pattern2 filename

例如统计文件数量的时候（往往第一行要减掉）

root@ubuntu:/data6/light/images/others# grep -c -e "JPEG" -e"jpg" <(ll)16581root@ubuntu:/data6/light/images/others# grep -c "" <(ll)16582

grep and 查询

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1. grep -E ‘pattern1.*pattern2’ filename

2. grep -E ‘pattern1.*pattern2|pattern2.*pattern1’ filename

grep not 查询

grep -v

grep practice(-A -B..)

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比如在查看caffe训练的时候，看accuracy同时看前后两行的loss信息以及learning rate

grep -inr “Text” folder/to/be/searched/搜索当前目录下所有含有”Text”的文件

The r stands for recursive and so will search in the path specified and also its sub-directories. （循环递归当前目录以及子目录）

i stands for ignore case (optional in your case).（忽略大小写）
-n is line number

If your grep doesn’t support recursive search, you can combine find with xargs:

find / -type f | xargs grep ‘text-to-find-here’
当前目录下查找txt文件
find . -name “*.txt” | xargs grep -i “text_pattern”

Display only the file names which matches the given pattern using grep -l（查找含有指定字符串的文件）

$ grep -l this demo_*demo_filedemo_file1

Searching in all files recursively using grep -r（查找多有文件，这样方便统计日志）
$ grep -r “error_msg” *

linux命令的很多技巧基本google到的，很多参考下面这个bolg
http://www.thegeekstuff.com/category/sed/

关键词英文对了，很多问题瞬间解决。