comparing two files last modification date

[Database Administrator]

I have two files, say file1 and file2, I would like to find out which
of these two files was modified last.

Thanks

[Database Administrator]

puzzlecracker wrote:
> I have two files, say file1 and file2, I would like to find out which
> of these two files was modified last.

You can inspect that roughly with ls -l
If you want it with higher precision have a look at the command stat.
For visual inspection with user friendly dates use

stat -x%y file1 file2

and if you want to do arithmetic use the output values (seconds) from

stat -x%Y file1 file2


Janis

>
> Thanks

[Database Administrator]

On Nov 13, 9:49*am, Janis Papanagnou
wrote:
> puzzlecracker wrote:
> > I have two files, say file1 and file2, I would like to find out which
> > of these two files was modified last.
>
> You can inspect that roughly with ls -l
> If you want it with higher precision have a look at the command stat.
> For visual inspection with user friendly dates use
>
> * *stat -x%y file1 file2
>
> and if you want to do arithmetic use the output values (seconds) from
>
> * *stat -x%Y file1 file2
>
> Janis
>
>
>
> > Thanks

argh stat: invalid option -- x

[Database Administrator]

On Nov 13, 10:13*am, puzzlecracker wrote:
> On Nov 13, 9:49*am, Janis Papanagnou
> wrote:
>
>
>
> > puzzlecracker wrote:
> > > I have two files, say file1 and file2, I would like to find out which
> > > of these two files was modified last.
>
> > You can inspect that roughly with ls -l
> > If you want it with higher precision have a look at the command stat.
> > For visual inspection with user friendly dates use
>
> > * *stat -x%y file1 file2
>
> > and if you want to do arithmetic use the output values (seconds) from
>
> > * *stat -x%Y file1 file2
>
> > Janis
>
> > > Thanks
>
> argh stat: invalid option -- x

Try "man stat" on your system (e.g. on an Ubuntu system here stat has
a "-c" option instead of a "-x" option).

[Database Administrator]

2008-11-13, 06:35(-08), puzzlecracker:
> I have two files, say file1 and file2, I would like to find out which
> of these two files was modified last.
[...]

Some shells (ksh, zsh, bash) have [[ file1 -nt file2 ]].

In the standard toolchest, you've got "find -newer" and "ls -t"

if find file1 -prune -newer file2 -print | grep -q .; then
echo "file1 is newer than file2"
fi

Or:

NL='
'
case $(ls -td file1 file2) in
("file1${NL}file2") echo "file1 is not older than file2";;
("file2${NL}file1") echo "file2 is not older than file1";;
(*) echo >&2 error;;
esac


--
Stéphane

[Database Administrator]

puzzlecracker wrote:
> On Nov 13, 9:49 am, Janis Papanagnou
> wrote:
>
>>puzzlecracker wrote:
>>
>>>I have two files, say file1 and file2, I would like to find out which
>>>of these two files was modified last.
>>
>>You can inspect that roughly with ls -l
>>If you want it with higher precision have a look at the command stat.
>>For visual inspection with user friendly dates use
>>
>> stat -x%y file1 file2
>>
>>and if you want to do arithmetic use the output values (seconds) from
>>
>> stat -x%Y file1 file2
>>
>>Janis
>>
>>
>>
>>
>>>Thanks
>
>
> argh stat: invalid option -- x

Sorry, mistyped! I meant -c (x and c are adjacent on my keyboard).

Janis

[Database Administrator]

On Nov 13, 10:28*am, Stephane CHAZELAS
wrote:
> 2008-11-13, 06:35(-08), puzzlecracker:> I have two files, say file1 and file2, I would like to find out which
> > of these two files was modified last.
>
> [...]
>
> Some shells (ksh, zsh, bash) have [[ file1 -nt file2 ]].
>
> In the standard toolchest, you've got "find -newer" and "ls -t"
>
> if find file1 -prune -newer file2 -print | grep -q .; then
> * echo "file1 is newer than file2"
> fi
>
> Or:
>
> NL='
> '
> case $(ls -td file1 file2) in
> * ("file1${NL}file2") echo "file1 is not older than file2";;
> * ("file2${NL}file1") echo "file2 is not older than file1";;
> * (*) echo >&2 error;;
> esac
>
> --
> Stéphane
Thanks the following doesnt quite do what I want. First I want to see
if file exist and if it does, I want to compare

if -e $obj || find $i -prune -newer $obj -print | grep -q . ;
then


fi


Thanks

[Database Administrator]

puzzlecracker wrote:
>
> Thanks the following doesnt quite do what I want. First I want to see
> if file exist and if it does, I want to compare
>
> if -e $obj || find $i -prune -newer $obj -print | grep -q . ;

if [[ -e $obj ]] || ...

Or use single [...] instead of [[...]] in case you use an old shell.

Janis

> then
>
>
> fi
>
>
> Thanks

[Database Administrator]

2008-11-13, 07:51(-08), puzzlecracker:
[...]
> Thanks the following doesnt quite do what I want. First I want to see
> if file exist and if it does, I want to compare
>
> if -e $obj || find $i -prune -newer $obj -print | grep -q . ;
> then
>
>
> fi
[...]

-e is not a valid command. The command that does tests is the
"[" command (aka test). "||" means OR, you want "&&" for AND.
You've forgotten the quotes around the variable expansions. But
you don't need to run the "[" command anyway, you can as well do:

if find "$i" -prune -newer "$obj" -print 2> /dev/null | grep -q .
then ...
fi

find will not output anything on its standard output if it can't
find "$i", so the test will fail.

Note that the above will fail to work properly if "$i" starts
with a "-".

--
Stéphane

[Database Administrator]

2008-11-13, 17:12(+01), Janis Papanagnou:
> puzzlecracker wrote:
>>
>> Thanks the following doesnt quite do what I want. First I want to see
>> if file exist and if it does, I want to compare
>>
>> if -e $obj || find $i -prune -newer $obj -print | grep -q . ;
>
> if [[ -e $obj ]] || ...
>
> Or use single [...] instead of [[...]] in case you use an old shell.
[...]

Or in case you want to write a standard script that can run with
any POSIX compliant shell, which in general I'd recommend.

[ -e "$obj" ] or ls -Ld -- "$obj" > /dev/null 2>&1

Note that [ -e will return false for a symlink to a non-existent
file (or a file in a directory you don't have access to).

The equivalent of
ls -d -- "$obj" > /dev/null 2>&1 would be:
[ -e "$obj" ] || [ -L "$obj" ].

Another note on symlinks.

find x -newer y and ls -t x y will compare the dates of x and y
even if x or y is a symlink.

While ls -tL x y, find -H x -newer y and [[ x -nt y ]] will
compare the dates of the targets of the symlinks.

--
Stéphane