Paul W. Abrahams wrote:

On Friday 15 October 2004 7:46 pm, Patrick Shanahan wrote:

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* Donald D Henson [10-15-04 18:43]:

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I have a simple problem that I'm sure has a simple answer but I don't seem to be able to figure it out. Where the heck do you put a crontab that is to run as root? (It's running rdiff-backup nightly.) Any assistance will be appreciated.

in a root shell (ie: as root) issue: crontab -e

That will work, of course, but I find it more convenient to create a crontab in a local file ~/mycrontab (in this case /home/root/mycrontab) and then do: crontab ~/mycrontab crontab -l # check that it worked

Paul

The penny finally dropped and man do I feel stupid. After struggling with this problem for several days, it suddently occurred to me that while the default file name for the cron table is "crontab", crontab is also a command. Once I realized that I had to issue the command "crontab <path to crontab file>", everything works as it should. I want to thank everyone who responded. Each reply played a part in killing my stupidity, at least on this problem. -- Donald D. Henson, Managing Director West El Paso Information Network The "Non-Initiation of Force Principle" Rules

On Monday 18 October 2004 11:53 am, Danny Sauer wrote:

Wouldn't it be easier just to run "crontab -e", which starts up the editor specified by $EDITOR, rather than starting up the editor, saving a file, and then running crontab on that file? Seems like you're adding some extra steps to the process...

I'm a little confused about how "crontab -e" works. The man page for crontab(1) says: The -e option is used to edit the current crontab using the editor specified by the VISUAL or EDITOR environment variables. What if VISUAL and EDITOR specify two different editors? Why are there two knobs on the same control, I wonder? By the way, I did a little experiment with EDITOR and discovered that it's effective as an environment variable only if it's exported. Paul

On Tuesday, 19 October 2004 00.52, Paul W. Abrahams wrote:

On Monday 18 October 2004 11:53 am, Danny Sauer wrote:

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Wouldn't it be easier just to run "crontab -e", which starts up the editor specified by $EDITOR, rather than starting up the editor, saving a file, and then running crontab on that file? Seems like you're adding some extra steps to the process...

I'm a little confused about how "crontab -e" works. The man page for crontab(1) says:

The -e option is used to edit the current crontab using the editor specified by the VISUAL or EDITOR environment variables.

What if VISUAL and EDITOR specify two different editors? Why are there two knobs on the same control, I wonder?

Historically it's not the same control. VISUAL is supposed to be a full screen editor like vi or pico, while EDITOR is a line editor like ed. Nowadays I guess they're both there for historical and compatibility reasons

By the way, I did a little experiment with EDITOR and discovered that it's effective as an environment variable only if it's exported.

It isn't an environment variable if it isn't exported. If you don't export it, it's only visible to the current process and isn't inherited when you launch a new process

On Monday 18 October 2004 7:09 pm, Anders Johansson wrote:

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What if VISUAL and EDITOR specify two different editors? Why are there

two

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knobs on the same control, I wonder?

Historically it's not the same control. VISUAL is supposed to be a full screen editor like vi or pico, while EDITOR is a line editor like ed. Nowadays I guess they're both there for historical and compatibility reasons

I just did a little experiment and determined that if both are set, VISUAL takes precedence. Paul

Patrick, On Monday 18 October 2004 16:19, Patrick Shanahan wrote:

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I suggest a copy of the abs-guide.pdf should be on everyone's desk/computer. Advanced Bash Scripting Guide.

Thanks for the reference. Perhaps it's worth pointing out that at 580 pages, this guide is really a full-fledged book. One place I found it (i.e., the first Google hit) is at the Linux Documentation Project: http://www.tldp.org/LDP/abs/html/>. From that page you can find a link to the PDF version (http://www.tldp.org/LDP/abs/abs-guide.pdf>). However, given that at least in some ways PostScript viewing is preferable to PDF viewing on Linux, note that there's an unlinked PostScript version at http://www.tldp.org/LDP/abs/abs-guide.ps.gz>. (Also keep in mind that KGhostView will open gzip-ed PostScript files directly, so there's no need to keep those largish PostScript files around.) Lastly I'll mention that I'm fond of the Developer's Library (http://www.developers-library.com/>) book "Linux Shell Scripting with Bash".

-- Patrick Shanahan

Randall Schulz

Danny Sauer wrote:

Paul wrote regarding 'Re: [SLE] crontab' on Fri, Oct 15 at 21:16:

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That will work, of course, but I find it more convenient to create a crontab in a local file ~/mycrontab (in this case /home/root/mycrontab) and then do: crontab ~/mycrontab crontab -l # check that it worked

Doesn't that command replace the current crontab with the one specified on the command line? Wouldn't it be easier just to run "crontab -e", which starts up the editor specified by $EDITOR, rather than starting up the editor, saving a file, and then running crontab on that file? Seems like you're adding some extra steps to the process...

Eh, I guess "There's More Than One Way To Do It". Whatever works. :)

--Danny

Danny, in this case remember to read your command line before pressing enter; just to check if you get "crontab -r" instead of "crontab -e" - R and E keys are 'neighbors keys', and you'll get almost *opposite* behavior in each case... :-) I never did that, but saw a friend suffering from such mistake -- Marcos Lazarini