Problem with continuous monitoring of files with tail command

[ Thanks to An Anonymous Reader for
this link. ]

“If you can’t get tail command to continuously
monitor a file, then read on. I was working on a script yesterday,
a part of which depended on continuous monitoring of a text file. I
had used our trusty old “tail” command for this but
while testing by manually putting in some data into the file, it
was failing but curiously it was working fine when used in actual
scenario. Befuddled, I did a simple test. I created a simple text
file “a.txt” with a few lines of data and then ran the
following command:

“…It showed the last few lines of the file and kept waiting.
So far so good. Then I opened the file in vim editor, wrote a few
more lines, saved the file and then waited but nothing in the
window that was running the tail command. Thinking that the data
might be buffered and not flushed to the disc yet, I ran the sync
command but still nothing.”

Complete Story