tail command not updating output for debug files

Question

I know that tail -f /var/log/messages will be keep updating on screen as the contents of file gets updated. But when I tried the same thing with a debug file system's file it is not working , any idea?

I tried ftrace and tried this: tail -f trace it is not working ?

Note, I can see the contents actually getting by using watch -n1 cat trace.

The thing is, `tail -f` only works with files which are appended to. Maybe your debug file is not appended but overwritten with every run? — , Dec 30 '13 at 12:23
Does this answer your question? [Continuously monitor logs with tail that are occasionally rotated](https://serverfault.com/questions/53699/continuously-monitor-logs-with-tail-that-are-occasionally-rotated) — user202729, Oct 19 '21 at 15:42

score 4 · Accepted Answer · answered Dec 30 '13 at 12:32

tail -f works on the file descriptor, not on the file name. If the file is being overwritten, or deleted and re-created, tail -f won't be able to track that.

In gnu tail there's the option --follow=name or -F which will track the file name rather than the inode/file descriptor.

tail command not updating output for debug files

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