Very Computer

by **mvgor..** » Fri, 10 Mar 2000 04:00:00

Hi,

I hope i can drop my question about Linux shell programming here?

I'm writing a script in bash to find files. I'm using the slocate
programm, which is being runned every hour using a cron job, to create
it's database.

Now i want to know how long it is ago that the database has been
recreated. Zo i need to check the date and time from that file and
compare it with the current date and time. I know there must be easy to
do but i can't find the trick to do it.

Maikel van Gorkom

Sent via Deja.com http://www.deja.com/
Before you buy.

by **Ken Pizzi** » Fri, 10 Mar 2000 04:00:00

>I hope i can drop my question about Linux shell programming here?

As long as it's shell programming on unixish systems, it's on-topic.

Quote:>Now i want to know how long it is ago that the database has been
>recreated. Zo i need to check the date and time from that file and
>compare it with the current date and time. I know there must be easy to
>do but i can't find the trick to do it.

Since you're running on Linux the answer is simplified: you'll
be running with GNU date installed and so you can:
now=$(date +%s)
then=$(date -r "$file" +%s)
diff=$((now - then))
echo "$file was last modified $diff seconds ago"
Or, if you're a one-liner fan:
diff=$(( $(date +%s) - $(date -r "$file" +%s) ))

--Ken Pizzini

by **Daniel Frazie** » Fri, 10 Mar 2000 04:00:00

To expand on that, this will produce a time in hours, minutes and
seconds.

now=$(date +%s)
then=$(date -r "$file" +%s)
diff=$((now - then))
echo -n "$file was last modified "
HRS=`expr $diff / 3600`
MIN=`expr $diff % 3600 / 60`
SEC=`expr $diff % 3600 % 60`
if [ $HRS -gt 0 ]
then
echo -n "$HRS hrs. "
fi
if [ $MIN -gt 0 ]
then
echo -n "$MIN mins. "
fi
if [ $SEC -gt 0 ]
then
if [ $MIN -gt 0 ]
then
echo "and $SEC secs. ago."
elif [ $HRS -gt 0 ]
then
echo "and $SEC secs. ago."
else
echo "$SEC secs. ago."
fi
fi

Hope this helps.
Daniel Frazier

> >I hope i can drop my question about Linux shell programming here?

> As long as it's shell programming on unixish systems, it's on-topic.

> >Now i want to know how long it is ago that the database has been
> >recreated. Zo i need to check the date and time from that file and
> >compare it with the current date and time. I know there must be easy to
> >do but i can't find the trick to do it.

> Since you're running on Linux the answer is simplified: you'll
> be running with GNU date installed and so you can:
> now=$(date +%s)
> then=$(date -r "$file" +%s)
> diff=$((now - then))
> echo "$file was last modified $diff seconds ago"
> Or, if you're a one-liner fan:
> diff=$(( $(date +%s) - $(date -r "$file" +%s) ))

> --Ken Pizzini

by **Ken Pizzi** » Fri, 10 Mar 2000 04:00:00

>To expand on that, this will produce a time in hours, minutes and
>seconds.

>now=$(date +%s)
>then=$(date -r "$file" +%s)
>diff=$((now - then))
>echo -n "$file was last modified "
>HRS=`expr $diff / 3600`
>MIN=`expr $diff % 3600 / 60`
>SEC=`expr $diff % 3600 % 60`

Better than calling the external "expr" command would be to use
the shell's builtin arithmetic capabilities:
HRS=$((diff / 3600))
MIN=$((diff % 3600 / 60))
SEC=$((diff % 60))

Quote:>if [ $HRS -gt 0 ]
>then
> echo -n "$HRS hrs. "
>fi
>if [ $MIN -gt 0 ]
>then
> echo -n "$MIN mins. "
>fi
>if [ $SEC -gt 0 ]
>then
> if [ $MIN -gt 0 ]
> then
> echo "and $SEC secs. ago."
> elif [ $HRS -gt 0 ]
> then
> echo "and $SEC secs. ago."
> else
> echo "$SEC secs. ago."
> fi
>fi

Seems a bit verbose; how about:
((HRS > 0)) && echo -n "$HRS hrs. "
((MIN > 0)) && echo -n "$MIN mins. "
((HRS > 0 || MIN > 0)) && echo -n "and "
echo "$SEC secs. ago."

--Ken Pizzini

by **Daniel Frazie** » Fri, 10 Mar 2000 04:00:00

This was actually a part of a script that was the first script that I
wrote that was longer than a few lines, so I'm sure that there is plenty
that could be cleaned up/optimized. Thanks for the input, I always
appreciate constructive comments.

Daniel Frazier

> >To expand on that, this will produce a time in hours, minutes and
> >seconds.

> >now=$(date +%s)
> >then=$(date -r "$file" +%s)
> >diff=$((now - then))
> >echo -n "$file was last modified "
> >HRS=`expr $diff / 3600`
> >MIN=`expr $diff % 3600 / 60`
> >SEC=`expr $diff % 3600 % 60`

> Better than calling the external "expr" command would be to use
> the shell's builtin arithmetic capabilities:
> HRS=$((diff / 3600))
> MIN=$((diff % 3600 / 60))
> SEC=$((diff % 60))

> >if [ $HRS -gt 0 ]
> >then
> > echo -n "$HRS hrs. "
> >fi
> >if [ $MIN -gt 0 ]
> >then
> > echo -n "$MIN mins. "
> >fi
> >if [ $SEC -gt 0 ]
> >then
> > if [ $MIN -gt 0 ]
> > then
> > echo "and $SEC secs. ago."
> > elif [ $HRS -gt 0 ]
> > then
> > echo "and $SEC secs. ago."
> > else
> > echo "$SEC secs. ago."
> > fi
> >fi

> Seems a bit verbose; how about:
> ((HRS > 0)) && echo -n "$HRS hrs. "
> ((MIN > 0)) && echo -n "$MIN mins. "
> ((HRS > 0 || MIN > 0)) && echo -n "and "
> echo "$SEC secs. ago."

> --Ken Pizzini

by **Michael Wa** » Sat, 11 Mar 2000 04:00:00

> now=$(date +%s)
> then=$(date -r "$file" +%s)
> diff=$((now - then))

((diff = now - then)) is better.
--
Michael Wang

http://www.mindspring.com/~mwang

Very Computer

date/time of a file compare with current date/time

date/time of a file compare with current date/time

date/time of a file compare with current date/time

date/time of a file compare with current date/time

date/time of a file compare with current date/time

date/time of a file compare with current date/time

date/time of a file compare with current date/time