If I run a script from /home/<user>/<dir>/script.sh, as root, the cron works pretty well. But If I run the script from /root/<dir>/script.sh (as root, again), the cron does not seem to work.
Having run afoul of various default $PATHs in the past when using 'cron', I always spell in full the absolute $PATH for each executable file and each target file. I always assume that 'cron' has NO $PATH set and has NO current-working-directory.
In other words don't use a command like
"myprocess abc*.txt"
but do it in full like
"/usr/localbin/myprocess /home/jvs/abc*.txt".
Alternatively, create a bash script which does the job, and call that bash script with a full absolute path, such as
"/usr/local/bin/myprocess_abc_txts".
If you need to have some flexibility in the script, use environment variables which are set specifically within the bash script you call with 'cron'.
I think you need to add a little more information. I'd guess it is a permissions thing though. Add the permissions of the file, the directories, and the line in your crontab so we can help. Also, if you are putting this in /root, are you running this in root's crontab?
Remember the environment - especially when run by cron rather than by root. When cron runs something, you probably don't have anything much set of your environment, unlike when you run a command via at. It is also not clear what your current directory will be. So, for commands that will be run by cron, use a script (as you're already doing) and make sure it sets enough of the environment for it to run. And make sure your environment setting code is not interactive!
On my machines, I have a mechanism such that the cron entry reads (for example):
23 1 * * 1-5 /usr/bin/ksh /work1/jleffler/bin/Cron/weekday
The weekday script in the Cron directory is a link to a standard script that first sets the environment and then runs the command /work1/jleffler/bin/weekday (in this case - it uses the name of the command to determine what to run).
The actual script in the Cron directory is:
: "$Id: runcron.sh,v 2.1 2001/02/27 00:53:22 jleffler Exp $"
#
# Commands to be performed by Cron (no debugging options)
# Set environment -- not done by cron (usually switches HOME)
. $HOME/.cronfile
base=`basename $0`
cmd=${REAL_HOME:-/real/home}/bin/$base
if [ ! -x $cmd ]
then cmd=${HOME}/bin/$base
fi
exec $cmd ${#:+"$#"}
I've been using it a while now - this version since 2001 - and it works a treat for me. I'm using a basic (Sun Solaris 10) implementation of cron; there may be new features in new versions of cron on other platforms to make some of this unnecessary. (The $REAL_HOME stuff is a weirdness of mine; pretend it says $HOME - though that makes some of the script unnecessary for you.) The .cronfile is responsible for the environment setting - it does quite a lot, but that's my problem, not yours.
It could be because you're looking for relative directories/files in the script which are located when running it from /home/ but not from /root, because /root is not in /home/root nor would it look like a users homefolder in /home/
Can you check and see if it is looking for relative files, or post the script?
On another note, why don't you just set it to run from a user's homefolder then?
Another way to run sh script is place your bash script in /usr/bin directory and simply run command bash yourscript.sh without adding /usr/bin/ directory
Related
Set up
I have several bashfiles on my computer which I want to run periodically.
I can run the bashfiles manually in Terminal (Mac OS), e.g. cd'ing myself to the correct folder and subsequently executing,
./France_run.txt
gives the desired result.
Problem
I do not want to run the bashfiles manually.
I've created cronjobs in crontab, e.g.
0 0 * * 2 /Users/mypath/France_run.txt
which should run each Tuesday at 00:00. However, nothing happens.
Am I only referring to the file and missing a 'run this script' command? Or is it something else?
You may be only referring to the file, and it's probably logging an error somewhere (usually /var/log/message, or in the mail file of the root user...which is disabled by default on Macs).
The thing about running scripts through cron is that it runs under a different environment. When you normally log in to a Bash session, certain environment variables get automatically set, so the system automatically checks for things like a path (locations in the file system where executables can be found). Different Unix like systems handle this situation slightly differently...I can't recall the details of how Macs deal with it, but on some systems, I've had to explicitly provide the full path to, for example, the Bash executable in order to get stuff to work.
The location of the executable for the scripts is usually /bin/bash, or /bin/sh, or something like that. So when going through a Bash session, if you call /Users/mypath/France_run.txt and that file is an executable Bash script (e.g. the first line is something like #!/bin/bash and the file's executable bit is set) then system knows to automatically run something like /bin/bash /Users/mypath/France_run.txt.
In the context of cron, however, you don't automatically get those conveniences, so you may have to spell out just about everything (i.e. specify the full paths to all binaries or executables). Again, this is not always the case. I just looked at a Debian system where I created some cron jobs to run scripts, and I didn't have to call /bin/bash there, but I do recall having to do something like that int the past on a Mac.
So your cron job may just need to specify the full path to the Bash binary:
0 0 * * 2 /bin/bash /Users/mypath/France_run.txt
And if France_run.txt makes any calls to system binaries (like ls), you may need to fully qualify those as well (/bin/ls instead of just ls).
Also, depending on how the script is written, it may even be necessary to cd into the directory of the script, as if you were running it manually:
0 0 * * 2 cd /Users/mypath; /bin/bash ./France_run.txt
(cd is a Bash built-in, so there's no path to specify there)
I have a script used for zipping a database and site files, then dumps the output into a backup folder on the server. The script runs fine from the command line, but it will not work through cron.
After much research, I am thinking that cron cannot run it in its current form because it runs in a different environment.
Here is the script, saved as file_name.sh
#!/bin/bash
NOW=$(date +"%Y-%m-%d-%H%M")
FILE="website.com.$NOW.tar"
BACKUP_DIR="/backupfolder"
WWW_DIR="/var/www/website/"
DB_USER="dbuser"
DB_PASS="dbpw"
DB_NAME="dbname"
DB_FILE="website.com.$NOW.sql"
WWW_TRANSFORM='s,^var/www/website,www,'
DB_TRANSFORM='s,^backupfolder,database,'
tar -cvf $BACKUP_DIR/$FILE --transform $WWW_TRANSFORM $WWW_DIR
mysqldump -u$DB_USER -p$DB_PASS $DB_NAME > $BACKUP_DIR/$DB_FILE
tar --append --file=$BACKUP_DIR/$FILE --transform $DB_TRANSFORM $BACKUP_DIR/$DB_FILE
rm $BACKUP_DIR/$DB_FILE
gzip -9 $BACKUP_DIR/$FILE
I currently have the script stored in /usr/local/scripts/
Is there something wrong with the above code that does not allow it to run through cron?
Which crontab should it go in? crontab -e from terminal, or /etc/crontab? They are two different files.
Several things come to mind: first, one of the most common problems with cron jobs is that generally crond runs things with a very minimal PATH (usually just /usr/bin:/bin), so if the script uses any commands from some other binaries directory, it'll fail. Where is mysqldump on your system (run which mysqldump if you aren't sure)? If this is the problem, adding PATH=/usr/local/bin:/usr/bin:/bin (or whatever's appropriate in your case) at the beginning of your script should fix it. Alternately, you can set PATH in the crontab file (put this line before the entry that runs your script).
If that's not the problem, my next step would be to capture the script's output, with something like:
1 1 * * * /usr/local/scripts/file_name.sh >/tmp/file_name.log 2>&1
... and see if the output is informative. BTW, as #tripleee mentioned, the format of your cron entry is suitable for the files crontab -e edits, but not for /etc/crontab. The /etc version has an additional field specifying which user to run the job as, e.g.
1 1 * * * eric /usr/local/scripts/file_name.sh >/tmp/file_name.log 2>&1
Best practice is to always use crontab -e (the resultant files are usually in /var/spool/cron/) and this works on every unix and linux platform I ever worked on.
Other common issues with cron execution are missing environment variables. Any environment variables set in .bash_profile (or .profile if you use korn shell) will not necessarily be present in the cron environment. This can be overcome by including them in your script.
As Gordon said, paths are another suspect. You can always full path you executables in your script (eg /bin/mysqldump). Some of the more cynical of us do this anyway to make sure we are executing what we intended as apposed to some other file of the same name in the current path.
I can only guess at your specific problem since you fixed it by creating /scripts, that perhaps the permissions on /usr/local/scripts directory did not allow execution by the cron user?
I have had to remove the extension (.sh) for cron to run in some instances.
So I fixed it. Not sure what the problem was, but this worked for me.
I originally had the scripts located in /usr/local/scripts/
I created a new directory here - /scripts/ and moved the scripts there. The new crontab -e command looked like this:
1 1 * * * bash /scripts/file_name.sh
Works perfectly. Again, I am not sure what the issue was before, but it works now.
I have a perl script and I scheduled it to run daily through crontab. The script is working fine if executed. But while executing through crontab, it's posting error mail to my mailbox.
Is there any thing that I should modify to successfully execute the script through crontab?
It could be a $PATH problem. Ensure that your Perl script either is on a place mentioned by $PATH, or has an absolute path in the crontab. This is also valid for any script or program that you run in the Perl script. The $PATH variable usually has to be set inside the crontab file.
It could be a file used in the Perl script having relative path, which could work when executed manually, but fail when run by cron (different working directories).
Does the Perl script have execute permissions (the x mode bit set)? This is not necessary when it's run with perl /path/to/script.pl, but would fail when it's run with /path/to/script.pl.
EDITED:
Suggestions for how to fix:
Add to $PATH in the crontab (for the sample script /path/to/script.pl):
PATH=/bin:/usr/bin:/path/to
Remember to include other needed paths as well (e.g. /bin and /usr/ucb).
Chances are there already is a PATH definition in the file. In that case, just append your path to it.
Alternatively, you can specify full path in the cron job line, e.g.:
17 * * * * root /path/to/script.pl
To fix permissions:
chmod a+r+x /path/to/script.pl
Recently I created a bash script which I am supposed to run in cron.
After preparing the bash script and its normal working, I put it in Cron and found that it was failing. As as second step , I removed all the environment dependencies i.e instead of just file.txt, I specified /home/blah-blah/file.txt
I still found the script to be failing still at one step. The step was a data processing tool.
The command i executed was /bin/blah-blah/processing_tool -parameter $INDEX where $INDEX is a variable calculated within the bash script.
Third step was to add the bash profile as source at the beginning of the bash script. Voila!!!! The script started executing perfectly from cron.
My question is why is this happening even after I removed all the environment dependencies from my script. Also I have heard that sourcing a cron job to a bash profile is not recommended. If so, Is there any other way in which I can avoid doing this.
Basicly: Anything started from cron starts with a totally clean slate.
You can make no assumptions whatsoever about the content of environment variables or whichever folder is the current folder at the start of any script run from cron.
Easiest solution:
cd to the desired directory to make sure your path is in the desired location.
source /etc/profile to mak sure you get the system wide environment variables setup.
source ~myuserid/.profile to read your personal environment settings. (~/.profile won't work as that would indicate the cron user.)
Then start executing the actual script.
Of course the approach above requires the cron process to have read access to your home-dir adn it's probably doing a lot more work thatn is actually required.
Slightly more complicated: Figure out which environment variables are required by the script and anything that gets called by the script.
Explicitly export these at the beginning of the cron script.
(P.s. replace /etc/profile and ~myuserid/.profile with whatever are the corresponding files for your shell of choice.)
A cron can be thought of as a separate user. So, this "user" may not "see" or "read" the same files as you do. It is thus essential that all path names etc. be defined in the absolute.
Every script runs within its own process. So, when you run a script, you can change the $SHELL and any other variable within but it will be lost once you get out of it. My guess is that the $INDEX variable computation may have had been computed within the script successfully but its use outside of the script may have failed. Without more information about what job it was, or what you wanted to do, it is hard to tell.
There are two ways to run a cron job:
As root, you can run su -user -c < job > in root crontab.
Sourcing your profile explicitly, as you have done.
You can also set environment variables within the crontab.
As user in the user crontab, you can run it like so: "/home/blah/.profile && myScript"
That said, there HAS to be something in your environment variables (apart from file extensions) that is not present when you run the cron job. You will have to execute that script with -x flag (in bash) and then pore over the output. Using a diff between your environment variables and that of root/cron might be a pointer. Also, check if there are some utilities that are being used in your scripts whose locations are not part of the $PATH variable for cron/root.
I have tried exporting my paths and variables and crontab still will not run my script. I'm sure I am doing something wrong.
I have a shell script which runs a jar file. This is not working correctly.
After reading around I have read this is commonly due to incorrect paths due to cron running via its own shell instance and therefore does not have the same preferences setup as my profile does.
Here is what my script looks like today after several modifications:
#!/bin/bash --
. /root/.bash_profile
/usr/bin/java -jar Pharmagistics_auto.jar -o
...
those are the most important pieces of the script, the rest are straightforward shell based.
Can someone tell me what I am doing wrong?
Try specifying the full path to the jar file:
/usr/bin/java -jar /path/to/Pharmagistics_auto.jar -o
I would just tell you what you have already ruled out: Check your path and environment.
Since you have alredy done this, start debugging. Like write checkpoints into a logfile to see how far your script gets (if even started at all), check the cronjob log file for errors, check your mail (cron sends mails on errors) and so on ...
Not very specific, sorry.
"exporting my paths and variables" won't work since crontab runs in a different shell by a different user.
Also, not sure if this is a typo in how you entered the question, but I see:
usr/bin/java
...and I can't help but notice you're not specifying the fully qualified path. It's looking for a directory named "usr" in the current working directory. Oft times for crontab, the cwd is undefined, hence your reference goes nowhere.
Try specifying the full path from root, like so:
/usr/bin/java
Or, if you want to see an example of relative pathing in action, you could also try:
cd /
usr/bin/java
A few thoughts.
Remove the -- after the #!/bin/bash
Make sure to direct script output seen by cron to mail or somewhere else where you can view it (e.g. MAILTO=desiredUser)
Confirm that your script is running and not blocked by a different long-running script (e.g. on the second line, add touch /tmp/MY_SCRIPT_RAN && exit)
Debug the script using set -x and set -v once you know it's actually running
Do you define necessary paths and env vars in your personal .profile (or other script)? Have you tried sourcing that particular file (or is that what you're doing already with /root/.bash_profile?)
Another way of asking this is: are you certain that whatever necessary paths and env vars you expect are actually available?
If nothing else, have you tried echo'ing individual values or just using the "env" command in your script and then reviewing the stdout?
provide full paths to your jar file, and what user are you running the crontab in? If you set it up for a normal user, do you think that user has permission to source the root's profile?