From 탱이의 잡동사니
Linux 명령어 watch 정보 정리
watch 명령어는 어떤 명령을 주기적으로 실행하고자 할 때 사용할 수 있는 프로그램이다.
Usage: watch [options] command Options: -b, --beep beep if command has a non-zero exit -c, --color interpret ANSI color sequences -d, --differences[=<permanent>] highlight changes between updates -e, --errexit exit if command has a non-zero exit -g, --chgexit exit when output from command changes -n, --interval <secs> seconds to wait between updates -p, --precise attempt run command in precise intervals -t, --no-title turn off header -x, --exec pass command to exec instead of "sh -c" -h, --help display this help and exit -v, --version output version information and exit
-d, --differences [permanent] Highlight the differences between successive updates. Option will read optional argument that changes highlight to be permanent, allowing to see what has changed at least once since first iteration. -n, --interval seconds Specify update interval. The command will not allow quicker than 0.1 second interval, in which the smaller values are converted. -p, --precise Make watch attempt to run command every interval seconds. Try it with ntptime and notice how the fractional seconds stays (nearly) the same, as opposed to normal mode where they continuously increase. -t, --no-title Turn off the header showing the interval, command, and current time at the top of the display, as well as the following blank line. -b, --beep Beep if command has a non-zero exit. -e, --errexit Freeze updates on command error, and exit after a key press. -g, --chgexit Exit when the output of command changes. -c, --color Interpret ANSI color sequences. -x, --exec command is given to sh -c which means that you may need to use extra quoting to get the desired effect. This with the --exec option, which passes the command to exec(2) instead. -h, --help Display help text and exit. -v, --version Display version information and exit.
$ watch -n1 date Every 1.0s: date Tue Aug 11 09:55:39 2015 Tue Aug 11 09:55:39 CEST 2015