명령어 - tail

tail - output the last part of files

-f
output appended data as the file grows; -f, --follow 과 같음

-c
output the last N bytes

-n
output the last N lines, instead of the last 10

--retry
keep trying to openn a file even if it is inaccessible when tail starts of if it becomes inaccessible later -- userful only with -f

-s, --sleep-interval=S
with -f, sleep for approximately S seconds (default 1.0) between iterations.