How to open the website at the certain moment using shell?

Question

I am looking for the solution how to open the website at the certain time. Considering the shell programming, it is possible to open website by the command:

$ open http://stackoverflow.com

How to do it at the certain moment if it is possible at all?

score 2 · Answer 1 · answered Apr 21 '15 at 01:40

You can use crontab to make it.

The crontab is a list of commands that you want to run on a regular schedule, and also the name of the command used to manage that list.

crontab stands for "cron table," because it uses the job scheduler cron to execute tasks; cron itself is named after "chronos," the Greek word for time.

Say You have a script /bin/openURL.sh to open a website,

30 21* * * /bin/OpenURL.sh

means executing it 21 : 30 every day.

More usage about crontab, see http://www.computerhope.com/unix/ucrontab.htm

score 2 · Answer 2 · edited May 23 '17 at 11:57

For one-time jobs (scheduled tasks), at commands are simple to schedule, as demonstrated by John1024's since-deleted answer, but at has drawbacks on OSX:

It must be enabled first; this is a one-time operation: sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.atrun.plist.
You must use sudo (have administrative privileges) to be able to schedule job with at.
If a job produces any output, it will be mailed to the user using mail, as stdout and stderr output (I don't know how to suppress this).
Example: schedule opening http://stackoverflow.com once, at 19:00 (7 PM):
- sudo bash -c 'echo "open http://stackoverflow.com" | at 19:00'

Using crontab for periodic jobs is an option on OSX; e.g., to schedule a job that opens http://stackoverflow.com every day at 19:00 (7 PM):

Run crontab -e to open the current user's cronfile in your editor.
Add the following line, save, and close the file:
- 0 19 * * * open http://stackoverflow.com
If a job produces any output, it will be mailed to the user using mail, as combined stdout and stderr output (I don't know how to suppress this).

However, the official recommendation on OSX is to use launchd for both one-time and periodic jobs:

launchd is very flexible and centralizes all job scheduling; as with crontab, there are system-wide and per-user jobs.
the downside is that the .plist files required to define jobs are cumbersome and non-trivial to create.

Using our previous example:

One-time job: (opens http://stackoverflow.com once, at 19:00 (7 PM))

Create file ~/test.plist (for a one-off job, the location doesn't matter).
Paste the following:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>
  <string>TestJob</string>
  <key>ProgramArguments</key>
  <array>
    <string>open</string>
    <string>http://stackoverflow.com</string>
  </array>
  <key>LaunchOnlyOnce</key>
  <true/>
  <key>StartCalendarInterval</key>
  <dict>
    <key>Hour</key>
    <integer>19</integer>
    <key>Minute</key>
    <integer>00</integer>
  </dict>
</dict>
</plist>

TestJob uniquely identifies your job.
Setting LaunchOnlyOnce to true ensures that the job is only run once.
From Terminal, run launchctl load ~/test.plist to load the job.

Periodic job: (opens http://stackoverflow.com every day at 19:00 (7 PM))

Create file ~/Library/LaunchAgents/testPeriodic.plist
- Note: The location matters: ~/Library/LaunchAgents is where per-user job-definition *.plist files must reside in order to be loaded automatically at every logon.
Paste the following:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>
  <string>TestJobPeriodic</string>
  <key>ProgramArguments</key>
  <array>
    <string>open</string>
    <string>http://stackoverflow.com</string>
  </array>
  <key>StartCalendarInterval</key>
  <dict>
    <key>Hour</key>
    <integer>19</integer>
    <key>Minute</key>
    <integer>00</integer>
  </dict>
</dict>
</plist>

Again, TestJobPeriodic uniquely identifies your job.
Jobs runs periodically by default (i.e., the absence of LaunchOnlyOnce makes the job periodic).
From Terminal, run launchctl load ~/Library/LaunchAgents/testPeriodic.plist to load the job.

For background information, see https://stackoverflow.com/a/23880156/45375.

How to open the website at the certain moment using shell?

2 Answers2