CODEWITHSUNDEEP
linuxcronsubstitution
Srikanth Power
Srikanth Power

Reputation: 170

Error bad substitution when scheduling script in crontab

a=$(iostat | awk 'FNR==4 {print $1}')
b=$(iostat | awk 'FNR==4 {print $2}')
c=$(iostat | awk 'FNR==4 {print $3}')
d=$(iostat | awk 'FNR==4 {print $4}')
e=$(iostat | awk 'FNR==4 {print $5}')
f=$(echo "scale=2;$a+$b+$c+$d+$e" | bc)
f=${f::-3}
echo $f >> /home/srikanth/tst

This is my code. I written it for cpu load. I wanted to schedule it in crontab for running it every minute. When i am executing it manually it working fine. but when i schedule it in crontab it is creating dead.letter with error

/home/srikanth/srk.sh: 7: /home/srikanth/srk.sh: Bad substitution

Can any one get me out of this

Thanks.....

Upvotes: 3

Views: 1649

Answers (1)

scai
scai

Reputation: 21469

"Bad substitution" sounds like your shell can't handle your script. What shebang are you using? I assume cron runs your script with a different shell than the one you are using, e.g. dash instead of bash.

Try to add the following shebang to the start of your script and see if it fixes your problem:

#!/bin/bash

Upvotes: 7

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