问题描述
在打开的终端中，当进程向文件写入数据时，我怎么能看到添加到文件中的所有新内容？
我尝试了
class Website:
"""The parent Website class"""
def __init__(self):
self.name = "X"
self.url = "X"
self.articles = "X"
def get_articles(self):
return "N/A"
def get_all_subclasses(cls):
all_subclasses = []
for subclass in cls.__subclasses__():
all_subclasses.append(subclass)
return all_subclasses
class Website1(Website):
"""Implementation for Website1"""
def __init__(self):
self.name = 'Website1'
self.url = 'www.google.com'
self.articles = self.get_articles()
def get_articles(self):
# insert custom logic to get articles based on url
articles = ['article 1','article 2','articl 3']
return articles
class Website2(Website):
"""Implementation for Website2"""
def __init__(self):
self.name = 'Website2'
self.url = 'www.google.com'
self.articles = self.get_articles()
def get_articles(self):
# insert custom logic to get articles based on url
articles = ['article 1','article 3']
return articles
site_articles = {}
websites = Website.get_all_subclasses(Website)
for site in websites:
site_articles[site().name] = site().articles
和 cat 的组合，但没有成功
解决方法
使用带 -f 的尾部
tail -f filename
取自 tail 的手册页：
-f,--follow[={name|descriptor}]
output appended data as the file grows;
an absent option argument means 'descriptor'
你不能用cat来做，你应该使用tail -f <filename>或less <filename>并压入F以等待数据。
$ man less
...
F Scroll forward,and keep trying to read when the end of file is reached. Normally this
command would be used when already at the end of the file. It is a way to monitor the
tail of a file which is growing while it is being viewed. (The behavior is similar to
the "tail -f" command.)
...