批量修改文件后缀
第一种：
#!/bin/bash
for fn in *.$1
do
mv $fn ${fn%$1}$2
done第二种：
find . -name "*.txt" | awk -F'[./]+' '{print $2}' | xargs -i -t mv {}.txt {}.shGREP 用户小技巧
文件如下：
# cat test.txt This is a test file a good day and no coludy Sit here and sing a song miss agao isting but money is money ! this is : hang only one line .
-w 匹配整个单词，避免单词字符匹配
# grep -w is test.txt This is a test file but money is money ! this is : hang
没有匹配到isting
-A 匹配之后的N行
# grep -A 3 Sit test.txt Sit here and sing a song miss agao isting but money is money ! this is : hang
-B 匹配之前的N行
# grep -B 2 Sit test.txt This is a test file a good day and no coludy Sit here and sing a song
-C 匹配前后N行
# grep -C 2 -i sit test.txt This is a test file a good day and no coludy Sit here and sing a song miss agao isting but money is money !
-c 统计匹配行数：
# grep -c is test.txt 4
-o 只显示匹配的字符串：
# grep -o money test.txt money money
-o -b 显示匹配的位置：
# grep -o -b Sit test.txt 45:Sit
交集与差集：
# cat 1.txt 1 2 3 4 # cat 2.txt 1 2 3 4 5 6
交集：
# grep -f 1.txt 2.txt 1 2 3 4
差集
# grep -vf 1.txt 2.txt 5 6
