[SOLVED] bash says "no such file or directory" when crontab runs the shell script

ymnoor21 · 03-21-2012, 07:16 PM

Hey Guys,
I have a problem that I need your help.

- I created a shell script like this (take_backup):

#!/bin/bash
mysqldump -u dbuser -pdbpass dbname > dbname_backup.sql

- Also I created a php file (backup.php) to execute the shell script

<?php
exec("bash take_backup");
?>

- My crontab looks like this:

MAILTO=myemail@mydomain.com
*/5 * * * * php /path/to/backup.php

- The shell script runs perfectly ok when I run the backup.php file from browser which uses the "take_backup" shell script behind. But my problem is I want to run the php file from the crontab and it doesn't get executed. Infact it emails me back with "bash: take_backup: No such file or directory"

FYI:
- "which bash" returns: /bin/bash
- I noticed that crontab is just not executing bash command in the backup.php file, other commands are working, ex: exec("ls -l");

Any reason??? Please help!!!!

Thanks
Yamin

Tinkster · 03-21-2012, 07:34 PM

Hi, welcome to LQ!

Simply specify the full path to take_backup in the PHP script.

Cheers,
Tink

evo2 · 03-21-2012, 07:35 PM

Hi,

did you try putting the full path to "take_backup" in your php script?
Eg.

Code:

<?php
exec("bash /path/to/take_backup");
?>

Also, why did you wrap your shell script in a php script? Wouldn't it make more sense to have a cron job like:

Code:

*/5 * * * * /path/to/take_backup

Evo2.

chrism01 · 03-21-2012, 07:40 PM

Expanding on good advice above; the cron env is minimal, which means you should specify the complete PATH to all cmds/files used, or source a file that defines them.
Also, forget the php in cron, just call the script as per evo2's suggestion.

ymnoor21 · 03-22-2012, 12:06 PM

Quote:

Originally Posted by evo2

Hi,

did you try putting the full path to "take_backup" in your php script?
Eg.

Code:

<?php
exec("bash /path/to/take_backup");
?>

Also, why did you wrap your shell script in a php script? Wouldn't it make more sense to have a cron job like:

Code:

*/5 * * * * /path/to/take_backup

Evo2.

Uhu, nothing is working. I've tried this:

Configured crontab with full path of the shell script (according to your suggestion). But with no luck. I've tried followings in the crontab:

A. MAILTO=myemail@mydomain.com
*/5 * * * * bash /path/to/take_backup
Output of A: I didn't receive any Cron Daemon email

B. MAILTO=myemail@mydomain.com
*/5 * * * * /path/to/take_backup
Output of B: I didn't receive any Cron Daemon email

C. MAILTO=myemail@mydomain.com
*/5 * * * * ./path/to/take_backup
Output of C: /bin/sh: ./path/to/take_backup: No such file or directory (in the Cron Daemon email)

Am I missing something? Any help would be very much appreciated...

Thanks
Yamin

Tinkster · 03-22-2012, 12:56 PM

What about crons log?

ymnoor21 · 03-22-2012, 01:15 PM

Quote:

Originally Posted by Tinkster

What about crons log?

CRON LOG OUTPUT:
[TRUNCATED BEFORE...]

Mar 22 10:00:01 www crond[1543]: (root) RELOAD (/var/spool/cron/root)
Mar 22 10:00:01 www CROND[6801]: (root) CMD (./path/to/take_backup)
Mar 22 10:00:01 www CROND[6802]: (root) CMD (/usr/lib64/sa/sa1 -S DISK 1 1)
Mar 22 10:01:01 www CROND[6825]: (root) CMD (run-parts /etc/cron.hourly)
Mar 22 10:01:01 www CROND[6826]: (root) CMD (run-parts /etc/cron.hourly)
Mar 22 10:01:01 www CROND[6827]: (root) CMD (./path/to/take_backup)
Mar 22 10:01:01 www run-parts(/etc/cron.hourly)[6825]: starting 0anacron
Mar 22 10:01:01 www run-parts(/etc/cron.hourly)[6826]: starting 0anacron
Mar 22 10:01:01 www anacron[6850]: Anacron started on 2012-03-22
Mar 22 10:01:01 www anacron[6850]: Normal exit (0 jobs run)
Mar 22 10:01:01 www anacron[6852]: Anacron started on 2012-03-22
Mar 22 10:01:01 www anacron[6852]: Normal exit (0 jobs run)
Mar 22 10:01:01 www run-parts(/etc/cron.hourly)[6855]: finished 0anacron
Mar 22 10:01:01 www run-parts(/etc/cron.hourly)[6856]: finished 0anacron
Mar 22 10:01:30 www crontab[6864]: (root) BEGIN EDIT (root)
Mar 22 10:01:36 www crontab[6864]: (root) REPLACE (root)
Mar 22 10:01:36 www crontab[6864]: (root) END EDIT (root)
Mar 22 10:02:01 www crond[1543]: (root) RELOAD (/var/spool/cron/root)
Mar 22 10:06:29 www crontab[6934]: (root) BEGIN EDIT (root)
Mar 22 10:06:35 www crontab[6934]: (root) END EDIT (root)
Mar 22 10:10:01 www CROND[6986]: (root) CMD (/usr/lib64/sa/sa1 -S DISK 1 1)
Mar 22 10:20:01 www CROND[7126]: (root) CMD (/usr/lib64/sa/sa1 -S DISK 1 1)
Mar 22 10:30:01 www CROND[7241]: (root) CMD (/usr/lib64/sa/sa1 -S DISK 1 1)
Mar 22 10:40:01 www CROND[7260]: (root) CMD (/usr/lib64/sa/sa1 -S DISK 1 1)
Mar 22 10:50:01 www CROND[7280]: (root) CMD (/usr/lib64/sa/sa1 -S DISK 1 1)
Mar 22 11:00:01 www CROND[7319]: (root) CMD (/usr/lib64/sa/sa1 -S DISK 1 1)
Mar 22 11:01:01 www CROND[7329]: (root) CMD (run-parts /etc/cron.hourly)
Mar 22 11:01:01 www CROND[7330]: (root) CMD (run-parts /etc/cron.hourly)
Mar 22 11:01:01 www run-parts(/etc/cron.hourly)[7330]: starting 0anacron
Mar 22 11:01:01 www run-parts(/etc/cron.hourly)[7329]: starting 0anacron
Mar 22 11:01:01 www anacron[7352]: Anacron started on 2012-03-22
Mar 22 11:01:01 www anacron[7354]: Anacron started on 2012-03-22
Mar 22 11:01:01 www anacron[7354]: Normal exit (0 jobs run)
Mar 22 11:01:01 www run-parts(/etc/cron.hourly)[7356]: finished 0anacron
Mar 22 11:01:01 www run-parts(/etc/cron.hourly)[7357]: finished 0anacron
Mar 22 11:01:01 www anacron[7352]: Normal exit (0 jobs run)

Seems like 0anacron is running as well. But don't think 0anacron is conflicting mine, as my crontab frequency is just about every five minutes. What do you think?

Also, my OS is: CentOS Linux release 6.0 (Final)
So I checked the cron log's default file location: /var/log and did this:
vi /var/log/cron (which is the latest)

Thanks
Yamin

Tinkster · 03-22-2012, 01:28 PM

Just for good measure also check
grep -ril cron /var/log/

I'd expect to see a line for your user, somewhere.

Can you match the attempts that had errors w/ any cron
times in the system logs?

ymnoor21 · 03-22-2012, 01:41 PM

Quote:

Originally Posted by Tinkster

Just for good measure also check
grep -ril cron /var/log/

/var/log/cron
/var/log/cron-20120226
/var/log/cron-20120311
/var/log/audit/audit.log
/var/log/btmp-20120301
/var/log/cron-20120318
/var/log/anaconda.yum.log
/var/log/anaconda.log
/var/log/cron-20120304
/var/log/secure
/var/log/vsftpd.log

Quote:

Originally Posted by Tinkster

- I'd expect to see a line for your user, somewhere.

- Can you match the attempts that had errors w/ any cron
times in the system logs?

- What do you mean?

lithos · 03-22-2012, 02:54 PM

Hi,

did you run the mysqlbackup from "take_backup" with full path too ?

Code:

for example:
/sbin/mysqldump ....

ymnoor21 · 03-22-2012, 03:58 PM

Quote:

Originally Posted by lithos

Hi,

did you run the mysqlbackup from "take_backup" with full path too ?

Code:

for example:
/sbin/mysqldump ....

Yes I did try this too:
/var/lib/mysqldump -u username -ppassword database > database_backup.sql

You know what. Funny thing is if I just run the php script via browser with this following shell command:
<?php
exec("bash /path/to/take_backup");
?>

then the database backup does gets created.

I just dont understand why would the same php script or direct invoking of the shell script (take_backup) wont work from crontab.

(

chrism01 · 03-22-2012, 06:45 PM

I think we need to start from the beginning; try

Code:

*/5 * * * * echo $(date) > /tmp/cron_test.log

Remember that if cron has an issue, it will email the owner and/or root acct, which you can check by logging in as the job owner and as root and using

Code:

mailx

Can we also see the contents of

Code:

/etc/cron.deny
/etc/cron.allow

if they exist.

ymnoor21 · 03-22-2012, 07:30 PM

Quote:

Originally Posted by chrism01

I think we need to start from the beginning; try

Code:

*/5 * * * * echo $(date) > /tmp/cron_test.log

Thu Mar 22 17:22:01 PDT 2012

Remember that if cron has an issue, it will email the owner and/or root acct, which you can check by logging in as the job owner and as root and using

Code:

mailx

Right now, I have redirected it to email me in the crontab:
MAILTO=myemail@mydomain.com
*/5 * * * * echo $(date) > /tmp/cron_test.log

Can we also see the contents of

Code:

/etc/cron.deny
/etc/cron.allow

if they exist.

/etc/cron.deny file exist but nothing in it.
/etc/cron.allow file do not exist.

FYI, crontab works perfectly for me (Ex: I tested one of my hourly email reminder program with cron), it just cant run with any shell script.

chrism01 · 03-22-2012, 07:37 PM

OK; next check where bash is

Code:

which bash

gives me '/bin/bash' on my system, so I'd construct a shell file (using a Linux editor such as vi/vim) called mytest.sh

Code:

#!/bin/bash
echo "in shell file"
echo $(date) > /tmp/cron_test.log

Code:

chmod a+x mytest.sh

Code:

#grab curr dir path info
pwd

and put that in cron

Code:

*/5 * * * * <put pwd output here>/mytest.sh > /tmp/cron_test.log 2>&1

ymnoor21 · 03-22-2012, 08:02 PM

Quote:

Originally Posted by chrism01

OK; next check where bash is

Code:

which bash

- it gives /bin/bash for my system too

Quote:

Originally Posted by chrism01

gives me '/bin/bash' on my system, so I'd construct a shell file (using a Linux editor such as vi/vim) called mytest.sh

Code:

#!/bin/bash
echo "in shell file"
echo $(date) > /tmp/cron_test.log

- I used vi to create mytest.sh and pasted your code above

Quote:

Originally Posted by chrism01

Code:

chmod a+x mytest.sh

- did the permission settings.

Quote:

Originally Posted by chrism01

Code:

#grab curr dir path info
pwd

and put that in cron

Code:

*/5 * * * * <put pwd output here>/mytest.sh > /tmp/cron_test.log 2>&1

- did that in my crontab

- Output of the /tmp/cron_test.log file:
Thu Mar 22 17:57:01 PDT 2012