How to get crontab execute commands on the default shell?

TheIndependentAquarius · 03-05-2017, 10:10 PM

Ubuntu 14.04 LTS

The script is:

Code:

    #!/bin/bash
    roscore

Error log is:

Code:

  roscore: not found

`crontab -l` says:

Code:

# Edit this file to introduce tasks to be run by cron.
    # 
    # Each task to run has to be defined through a single line
    # indicating with different fields when the task will be run
    # and what command to run for the task
    # 
    # To define the time you can provide concrete values for
    # minute (m), hour (h), day of month (dom), month (mon),
    # and day of week (dow) or use '*' in these fields (for 'any').# 
    # Notice that tasks will be started based on the cron's system
    # daemon's notion of time and timezones.
    # 
    # Output of the crontab jobs (including errors) is sent through
    # email to the user the crontab file belongs to (unless redirected).
    # 
    # For example, you can run a backup of all your user accounts
    # at 5 a.m every week with:
    # 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/
    # 
    # For more information see the manual pages of crontab(5) and cron(8)
    # 
    # m h  dom mon dow   command
    
    SHELL=/bin/bash
    @reboot cd /home/anisha/Desktop && sh mmanisha.sh >> p.log 2>&1

The thing is that when I run `roscore` directly on the terminal or I execute the script on the terminal, no errors are shown:

Code:

anisha@hrs-d-016:~$ echo $SHELL
    /bin/bash

    anisha@hrs-d-016:~$ roscore
    ... logging to /home/anisha/.ros/log/a6c6cee0-0220-11e7-bead-2c41388be92e/roslaunch-hrs-d-016-2807.log
    Checking log directory for disk usage. This may take awhile.
    Press Ctrl-C to interrupt
    Done checking log file disk usage. Usage is <1GB.
    
    started roslaunch server http://hrs-d-016:34770/
    ros_comm version 1.11.20
    
    
    SUMMARY
    ========
    
    PARAMETERS
     * /rosdistro: indigo
     * /rosversion: 1.11.20
    
    NODES
    
    auto-starting new master
    process[master]: started with pid [2819]
    ROS_MASTER_URI=http://hrs-d-016:11311/
    
    setting /run_id to a6c6cee0-0220-11e7-bead-2c41388be92e
    process[rosout-1]: started with pid [2832]
    started core service [/rosout]
    ^C[rosout-1] killing on exit
    [master] killing on exit
    ^Cshutting down processing monitor...
    ... shutting down processing monitor complete
    done

Where is crontab executing these commands such that it isn't able to find roscore?
How to get crontab execute commands on the default shell?

chrism01 · 03-05-2017, 10:48 PM

The crontab env is minimal and does not include your personal env eg $PATH.
The usual rule (& you'll find this advice all over) is to specify the complete path to all cmds and files used.
The other alternative is to add some code to your script that sets up the relevant PATH etc so that the cmd can run as if you were physically logged in.
(NB: cron is a dis-connected process; that is to say it has no knowledge/cxn to the screen, so don't use cmds that talk to the scrn)

TheIndependentAquarius · 03-05-2017, 10:55 PM

This time I added roscore path to the script:
/opt/ros/indigo/bin/roscore

This resulted in:

Code:

Traceback (most recent call last):
  File "/opt/ros/indigo/bin/roscore", line 36, in <module>
    from rosmaster.master_api import NUM_WORKERS
ImportError: No module named rosmaster.master_api

chrism01 · 03-05-2017, 11:02 PM

It looks like you may need to add some env vars; try

Code:

set
# and/or
env

You get similar issue if you try to run some ORACLE tools without exporting various env vars first.

Basically you need really to know how that cmd works and its dependencies; shouldn't be too hard.
You could try sourcing your .bashrc and/or .bash_profile (just the relevant parts).
(NB: there may be something being set in /etc/profile & /etc/profile.d/... etc.

TheIndependentAquarius · 03-06-2017, 12:01 AM

Well, I just put the script path in

Quote:

/etc/rc.local

Quote:

cat /etc/rc.local
#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

/home/anisha/Desktop/mmanisha.sh

exit 0

That worked.

This is the script:

Quote:

#!/bin/bash
source /opt/ros/indigo/setup.bash
roscore &

Thanks for your help though.