Linux head, tail

The head and tail of a Linux command every day

In fact, as long as you understand the meaning of these two English words, you can understand the role of these two commands. Head: The tail is the opposite: the tail, the former print the contents of the file, the latter print the file tail content

Head Test.log tail test.log both are default print 10 lines of course, the number of printed lines can also be adjusted by parameters, such as head-9 Test.log to print the first 10 lines at the beginning

Of course, the most likely person to contact Linux is Tailf, which is the tail-f command, at least I use the most. Tail-f filename will print out the most trailer in filename (it's all, just ensure that the most trailer content is displayed on the screen), especially in the case of viewing data warehousing, real-time printing of logs during program execution, and so on, Tailf is best.

In the last two days, I decided to write a summary daily, remember the knowledge points of the technology related to every day, record here, persist, and then feel the change. Whether you learn more or less every day, learning is progress. Today because of the company's task more, did not take too much time to learn, just read a little Python content and the daily learning of Linux commands.

Think about it, today, nearly a year of work, from a confused student status to the beginning of the workplace, the professional staff, they can feel the change, in the company is also increasingly recognized by the old staff, which may be in addition to wages, the important reason for joy (of course, Individuals or not shy of the pay of the incomparable love), more than half a month, this year recruited fresh graduates will come to practice, I know, when I saw them that moment, I will easily associate to last year's own. Testing compared to research and development, the overall business of the degree of control and requirements deeper and broader, and the focus of research and development staff may require more in-depth study, in short, that is, the code problem. So the test should not learn the code? This is nonsense, the answer is of course. If a tester has a high level of code, the product quality improvement will be far-reaching, which is why the white box test pay higher than the black box test, coupled with the scarcity of goods, the proportion of testers who know the code is small, the salary can only increase not reduced. Just say that I personally in this short year of work, is the experience of a white box test, black box testing and research and development to explore the subtle differences between the problem. The rules of the jungle apply to all places, and the strong will be respected by others. Then you have to improve your strength, it's a small goal (though not as small as Wang Jianlin's goal). The target has, then the next is to roll up the sleeves is dry. How do you do it? My way is to force myself! Make the daily plan, finish the quality on time, and output the summary. The completion of timely quality, it is very easy to achieve, after all IT workers who do not like to engage in technology, but the output of the summary is different, and the company has no external network, can only come back every night to summarize. However, think about it, this is also very good, memory summary of the knowledge of the master more solid, and every day to write a summary is also a patient life, no point toughness but insist not down, but I have, I have, strive to improve themselves, change their own!

Linux head, tail