- published: 15 Nov 2011
- views: 60654
cron is the time-based job scheduler in Unix-like computer operating systems. cron enables users to schedule jobs (commands or shell scripts) to run periodically at certain times or dates. It is commonly used to automate system maintenance or administration, though its general-purpose nature means that it can be used for other purposes, such as connecting to the Internet and downloading email.
Cron is driven by a crontab (cron table) file, a configuration file that specifies shell commands to run periodically on a given schedule. The crontab files are stored where the lists of jobs and other instructions to the cron daemon are kept. Users can have their own individual crontab files and often there is a system wide crontab file (usually in /etc
or a subdirectory of /etc
) which only system administrators can edit.
Each line of a crontab file represents a job and is composed of a CRON expression, followed by a shell command to execute. Some implementations of cron, such as that in the popular 4th BSD edition written by Paul Vixie and included in many Linux distributions, add a sixth field to the format: an account username that the specified job will be run by (subject to user existence and permissions). This is allowed only in the system crontabs, not in others which are each assigned to a single user to configure. The sixth field is also sometimes used for year instead of an account username; the nncron daemon for Windows does this. However vixie cron does not use the sixth column as a year and if used will treat the year as the command to run and fail.
A man is crying, takes me to a certain place.
Which I don't often find.
You see a family walking.
Always thinking of being somewhere else in
time.
So I fall face down in a rut.
I can't seem to get out of.
Please wake me.
Please give me some of it back.
The feelings I had.
Sometimes I wish I could be strong like you
. It doesn't matter.
Each time I wake I'm somehow feeling the truth.
I can't handle.
Let's get this party started.
I'm sick of being you.
You make me feel insane.
We don't give to you.
Let's get this party started.
You make me feel insane.
I want to be the one.
To make myself sane.
Time is ticking, it makes me feel content.
With what I have inside.
Constant paranoia surrounds me.
Everyone I see is out to get me.
So I fall face down in a rut.
I can't seem to get out of.
Please wake me.
Please give me some of it back.
The feelings I had.
Sometimes I wish I could be strong like you.
It doesn't matter.
Each time I wake I'm somehow feeling the truth.
I can't handle.
Let's get this party started.
I'm sick of being you.
You make me feel insane.
We don't give to you.
Let's get this party started.
You make me feel insane.
I want to be the one.
To make myself sane.
You make me feel insane.
You make me feel insane.
Sometimes I wish I could be strong like you.
It doesn't matter.
Each time I wake I'm somehow feeling the truth.
I can't handle.
Let's get this party started.
I'm sick of being you.
You make me feel insane.
We don't give to you.
Let's get this party started.
You make me feel insane.
I want to be the one.