Can't get Crontab jobs to work at all [duplicate] - linux

Question

This question already has answers here:
CronJob not running
(19 answers)
Closed 4 years ago.
New to Crontab use, I am trying to get a simple bash script to run.
add_temp:
#!/bin/bash
rnd1=$RANDOM
range1=20
let "rnd1 %= $range1"
rnd2=$RANDOM
range2=50
let "rnd2 %= $range2"
echo $rnd1
echo $rnd2
cd /var/www/html
sqlite3 test.db <<EOF
INSERT INTO temps (date, temp) VALUES ($rnd1, $rnd2 );
EOF
crontab -e:
SHELL:/bin/bash
* * * * * /var/www/html/add_temp
This doesn't seem to run at all. Works fine if run manually with /var/www/html/add_temp.

Answer 1

My guess is that the sqlite3 is not found when the cron daemon run the script.
You could modify the script and provide the full pathname of this command. Use a terminal to display the full pathname of the command:
type sqlite3
The cron daemon which will run the script does not have the exact same environment than the bash login shell used to run manually the script.
The variable that is usually differently set is PATH.
The first step to troubleshoot this situation is to compare the environments and debug the script.
I suggest to insert these lines below, after the very first line of the script
env
set -x
Run the script manually and redirect output, from a terminal:
/var/www/html/add_temp >/var/tmp/output_m.txt 2>&1
Change the crontab line for:
* * * * * /var/www/html/add_temp >/var/tmp/output_c.txt 2>&1
Wait that the cron daemon executes the script and compare the /var/tmp/output_m.txt and /var/tmp/output_c.txt files.
When the script will be fixed, remove the 2 debug lines from the script and restore the crontab original content.