Linux Watch Command Example
Watch is a simple command, with a few options. The basic syntax of watch command:
watch [-dhvt] [-n <seconds>] [--differences[=cumulative]] [--help] [--interval=<seconds>] [--no-title] [--version] <command>
Display errors/notices/warning being generated at run time every couple of seconds:
# watch tail /var/log/messages
Display disk usage after specified time interval.
# watch df -h
Display on server load and uptime at runtime.
# watch uptime
Let’s experience in difference between two successive outputs of “uptime” command repeated by watch.
#watch -n 20 -d uptime
Run free command for every 1/10 second
# watch -n 0.1 free
Display changes in output of a command with -d option of watch command.
# watch -d -n 1 free
Dont want to see time ticking at the start at watch screen, we can use -t to suppress it.
# watch -t free
Iteration delay
# watch [-n <seconds>] <command>
The default interval between the commands can be changed with -n switch. The following command will run the tail command after 5 seconds:
# watch -n 5 date
Successive output comparison
If you use -d option with watch command, it will highlight the differences between the first command output to every next command output cumulatively.
watch [-d or --differences[=cumulative]] <command>
Example
Let’s see the successive time outputs extracted using following watch command and observe how the difference is highlighted.
# watch -n 15 -d date
Output without title
If you don’t want to display extra details about the iteration delay and actual command run by watch then –t switch can be used.
watch [-t or --no-title] <command>
Let’s see the output of following command as an example.
# watch -t date
How can I find mounted partitions in my machine
Use below commands to know more about the mount points
cat /etc/mtab
df -h
Watch is a simple command, with a few options. The basic syntax of watch command:
watch [-dhvt] [-n <seconds>] [--differences[=cumulative]] [--help] [--interval=<seconds>] [--no-title] [--version] <command>
Display errors/notices/warning being generated at run time every couple of seconds:
# watch tail /var/log/messages
Display disk usage after specified time interval.
# watch df -h
Display on server load and uptime at runtime.
# watch uptime
Let’s experience in difference between two successive outputs of “uptime” command repeated by watch.
#watch -n 20 -d uptime
Run free command for every 1/10 second
# watch -n 0.1 free
Display changes in output of a command with -d option of watch command.
# watch -d -n 1 free
Dont want to see time ticking at the start at watch screen, we can use -t to suppress it.
# watch -t free
Iteration delay
# watch [-n <seconds>] <command>
The default interval between the commands can be changed with -n switch. The following command will run the tail command after 5 seconds:
# watch -n 5 date
Successive output comparison
If you use -d option with watch command, it will highlight the differences between the first command output to every next command output cumulatively.
watch [-d or --differences[=cumulative]] <command>
Example
Let’s see the successive time outputs extracted using following watch command and observe how the difference is highlighted.
# watch -n 15 -d date
Output without title
If you don’t want to display extra details about the iteration delay and actual command run by watch then –t switch can be used.
watch [-t or --no-title] <command>
Let’s see the output of following command as an example.
# watch -t date
How can I find mounted partitions in my machine
Use below commands to know more about the mount points
cat /etc/mtab
df -h
No comments:
Post a Comment