题目 Tenth Line Given a text file file.txt, print just the 10th line of the file. Example: Assume that file.txt has the following content: {代码...} Your script should output the tenth line, which is: {代码...} 注意点 需要注意一下它提供的note，其实test也涵盖了note提到的两点： Note: If the file co...

You may assume that each row has the same number of columns and each field is separated by the ' ' character.

Given a text file file.txt that contains list of phone numbers (one per line), write a one liner bash script to print all valid phone numbers.

Write a bash script to calculate the frequency of each word in a text file words.txt.