Python script does not run from crontab

Question

I have the following shell script. It checks whether the python script is running or not, and if not, it will start the python script. When I run it from command line like ./crontab.sh it works even from other places like MaskRCNN/crontab.sh. But when I put it into the crontab only the echos are working.

#!/bin/bash
out=$(ps aux | grep 'python train/train.py' | rev | cut -d ' ' -f 1| rev | wc -l)
if [ $out -eq "2" ];then
 echo "2 processes" >> /tmp/testing.txt
else
 echo "1 process" >> /tmp/testing.txt;
 cd /hdd1/Alex/testMaskRCNN_human_bodyparts/MaskRCNN_body;
 CUDA_VISIBLE_DEVICES=0 /usr/bin/python train/train.py
fi

The crontab looks like this:

* * * * * /hdd1/Alex/testMaskRCNN_human_bodyparts/MaskRCNN_body/crontab.sh

I hope there are enough details. Thank you

• Nullman: CUDA_VISIBLE_DEVICES=0 /usr/bin/python train/train.py is this supposed to run the script? because if it is i think the script needs to be surrounded by backticks
• ggupta: permission issue? might be chmod 777 crontab.sh would work
• Florentin Alexandru Iftimie: @Nullman Just tried that and it doesn't help :(
• Florentin Alexandru Iftimie: @ggupta neither that doesn't work
• Nullman: does you /tmp/testing.txt get updated with 1's?

Answer 1

try change train/train.py to full path...

• beliy: try also add ` > /tmp/cron.log` for loging output

Answer 2

I managed to debug it by adding the &>> operator.

`(/usr/bin/python /hdd1/Alex/testMaskRCNN_human_bodyparts/MaskRCNN_body/train/train.py &>> /tmp/testing.txt)`

And I found out that it missed an export:

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/cuda/lib64/

Final script:

#!/bin/bash
out=$(ps aux | grep '/usr/bin/python /hdd1/Alex/testMaskRCNN_human_bodyparts/MaskRCNN_body/train/train.py' | rev | cut -d ' ' -f 1 | rev | wc -l)
if [ $out -eq "2" ];then
 echo "2 processes" >> /tmp/testing.txt
else
 echo "1 process" >> /tmp/testing.txt
 export CUDA_VISIBLE_DEVICES=0
 export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/cuda/lib64/
 `(/usr/bin/python /hdd1/Alex/testMaskRCNN_human_bodyparts/MaskRCNN_body/train/train.py &>> /tmp/testing.txt)`
fi