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I have some scripts that do usual stuff like backing up MySql database, gz, tar some files and put them on FTP or sync with some other backup/mirror system. Some scripts are running quite frequently (like twice/thrice per hour). I am sending email with attached log output from commands after completion of job. It is quite a lot of email to keep track of.

I want to send email only when script fails to do something, that is when some command in script fails. How can I accomplish this?

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up vote 1 down vote accepted

Check the return value of the command and proceed accordingly. Normally all the Linux commands return 0 on success and some other number(specifying the reason) on failure.

Forgot to mention that the status of last command is saved in variable "$?". Thanks @bbaja42

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suppose I run a command using curl like curl --upload-file..... in a script how will I check status? i = curl --upload-file... then if [i eq 0]? – TheVillageIdiot Jun 29 '11 at 19:43
Status of last command is saved in variable "$?", so you can use [ $? -eq 0 ] – bbaja42 Jun 29 '11 at 19:49
@TheVillageIdiot: Example. – grawity Jun 29 '11 at 20:04
@bbaja42 and @grawity thanks for clearing up the things. I'm accepting @ssapkota's answer. – TheVillageIdiot Jun 30 '11 at 5:42

here is an example of script that I wrote for my work that's being used on daily basis

[alexus@wcmisdlin02 ~]$ sudo cat /usr/local/uftwf/mysql/
# $Id:,v 1.2 2011/05/31 16:02:56 alexus Exp $

if [ -d /var/lib/mysql/ ]; then
    cd /var/lib/mysql/
    for i in `ls`; do
            /usr/bin/mysqldump \
                --user=root \
                $i > /usr/local/uftwf/mysql/$i.sql
            /bin/gzip \
                --force \
                --quiet \
    /usr/bin/mysqladmin \
        --user=root \
    /usr/bin/mysql \
        --user=root \
        --execute='PURGE BINARY LOGS BEFORE subdate(curdate(), INTERVAL 1 DAY);'
[alexus@wcmisdlin02 ~]$ 

[alexus@wcmisdlin02 ~]$ sudo crontab -l -u mysql
@daily      /usr/local/uftwf/mysql/
[alexus@wcmisdlin02 ~]$ 

it will only email you once you get some sort of an error, it will not mail if job ran ok. This shell script resides in /usr/local/uftwf/mysql and that's where backups goes as well. Modify this script to FTP/rsync files to your remote location.

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Where's the conditional emailing bit? – Linker3000 Jun 29 '11 at 21:30

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