check if a command returns error before running script

Question

I'm writing a small restore script and before I run the actual script I want to check if all commands work..

I want to check if alias is added correctly on mysql..

So if the command # mysql returns an error I want to write an error message and then exit the script

#!/bin/sh

P.P · Accepted Answer · 2014-09-17 08:43:35Z

3

mysql -e 'exit' >/dev/null 2>&1 || { echo "mysql failed"; exit 1; }
# mysql works fine
# Your commands here

You could execute mysql and exit if it fails (either command is not found or alias not set correctly). In case, mysql works as expected, just exit out of it.

answered Sep 17, 2014 at 8:43

P.P

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Comments

fat-lobyte · Accepted Answer · 2014-09-17 08:35:27Z

0

You can check the return status of a command with the `$?' variable, but there is a simpler way:

if !mysql; then
   echo "An error has occured"
fi

answered Sep 17, 2014 at 8:35

fat-lobyte

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