UNIX shell 命令和管道中的初学者问题

Question

这是来自课程的材料。根据我的研究，代码总是以 shebang 开头

#! /bin/sh

我还想解决这个问题，我可能需要使用

的组合

wc, tail, grep, head

但是我很难把它放在一起。非常感谢您的帮助。

Write a shell command that processes a file 
that is 200 lines long or more. It outputs the number of those lines within lines 100 through 
199 *inclusive* that contain the character string “hello”.


Write a shell command that outputs the number of lines in the lines range 
100..199  that contain "hello, " but is NOT followed by "world".

Answer 1

第一个任务

head -n 199 $FILE | tail -n 100 | grep "hello" | wc -l

第二个任务

head -n 199 $FILE | tail -n 100 | grep "hello, " | grep -v "hello, world" | wc -l