借助Linux脚本从一行中提取整数？

Question

I have a file, one of whose line contains:

number 8

how can i use sed, grep or whatever linux script to find out what integer is there in front of the line that starts with "number"?

Thanks...

Answer 1

使用awk：

cat ./file.text | awk '/number/ {print $2}'

Answer 2

awk '$1=="number"{print $2}' file

Answer 3

使用grep并剪切，这将仅返回数字

cat ./file.txt | grep number | cut -d " " -f 2

Answer 4

Another way is to use awk :

awk '/number/ {print $2}' < ./file.txt

It's a single command, which some prefer. If it's a large file, you may prefer the cat | grep | cut cat | grep | cut cat | grep | cut -way, as the three programs run in separate processes.