Force File Overwrite

[cwsstins]

I've got a KSH script that overwrites a couple existing files. When I run it manually, I receive the question "are you sure you want to overwrite file?"

mv $DATA_DIR/file_A.dat $DATA_DIR/file_A.$day

When I set this job in cron, it changes the filename to "file_A." because the filename with today's day abbreviation already exists and it won't overwrite it. I've got chmod = 775, but what command can I set to force the overwrite and what's the syntax?

 

[PHV]

In the man page of the mv command have a look at the -f option.

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ181-2886

 

[cwsstins]

Gotcha...so basically,

mv -f $DATA_DIR/file_A.dat $DATA_DIR/file_A.$day

should do the trick, right?

 

[PHV]

it changes the filename to "file_A."
Are you sure that $day holds a value in your cron job ?

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ181-2886

 

[cwsstins]

Yes: day=`date +"%a" | tr '[A-Z]' '[a-z]'`

It's a new cron and it worked all last week just fine. As soon as it ran this morning and found a "fileA.mon" in the data directory, it didn't overwrite it.

 

[SamBones]

You may have an alias defined for [tt]mv[/tt]. The "[tt]-i[/tt]" option of the [tt]mv[/tt] command causes it to ask you first if the [tt]mv[/tt] would overwrite a file. My guess is that there's an alias defined like "[tt]mv='mv -i'[/tt]".

Type "[tt]alias[/tt]" to see if you have it defined.

See the [tt]man[/tt] page for [tt]mv[/tt] for more info.

 

[cwsstins]

I just checked and I don't have an alias for mv.

 

[KenCunningham]

Why not expand your date extension to include a ddmmyy construct, thus avoiding the need to overwrite. You can then remove any older files at your leisure and you have a historical record of events. Just a thought.

 

[hoinz]

And what happened last night ?
I think there already were files fileA.mon, fileA.tue and fileA.
My guess is, it renamed it to fileA. , in spite of the existing fileA. ?

 

[cwsstins]

Actually, my cron worked well this morning. It overwrote the existing fileA.tue as designed.

Ken, to answer your question, I actually do have that kind of convention going on for some of my log files:

`date +"%y"`
`date +"%m"`

in the filename with:
find $LOG_DIR -name "fileA*.log" -mtime +35 -exec rm {} \;

to delete after 35 days. But for the data files, we really only need to keep 7 days' worth, so the day extension works OK.