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Replace Crontab File Syntax ??

Hello Experts


1. FTP-ed Crontab from Solaris server.
2. Edited crontab off-line using a Unix text editor (Metapad)
3. FTPed back to Solaris server to a "home" folder.

I need to replace the existing crontab with the edited file. I have done this before quite some time ago and need to verify the syntax.

I believe it was

filename > crontab

...or something similar.

Please check / verify.


1 Solution
Eoin RyanI.T. ContractorCommented:
I'd be sure to check the /var/spool/cron/crontabs/ folder itself before doing an overwrite.

I've seen the folder "crontabs" but never a file called that. usually within the folder there are files to change and edit depending on what you want run when.

while your command will write filename to another file called "crontab" to me it looks a bit odd, but that's what it'll do if you want it to.
The location of crontab files varies due to different Linux distribution.
For RedHat/CentOS/Fedora, it is

For Ubuntu/Debian, it is

Say for root user, the crontab file is
/var/spool/cron/root  (or /var/spool/cron/crontabs/root)

You can backup them up first before your override them
cp  -pr /var/spool/cron   /path-to-backup-dir/

Just do:

crontab filename

That will overwrite your current crontab file...

If you want you could create a self fulfilling crontab of sorts:

--- updatecron.sh ----

if [ -e newcron ]; then
  crontab newcron
  rm newcron

---inside newcron ---
# Auto-Update Cron from FTP file...
* * * * * updatecron.sh

# Other cron entries here:
0 * * * * hourly.sh
you need to be careful while trying to edit the file and ftping it back, it should be ftped back in text or ascii mode

once this is done, the do the following steps

- save the current crontab file

crontab -l > mycron

- use the new crontab file e.g mynewcrontab

crontab mynewcrontab

- verify it

crontab -l

kboles101Author Commented:
This is the procedure we used; the extra verification step is very prudent. Thanks all.
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