cp -iu not working

Zeno McDohl · 07-07-2007, 02:37 PM

I'm trying to do cp -iu *.[ch] ../../mud/src/ to move all *.h and *.c files to another directory, but only overwrite those that are older than my current directory (thus the use of u). But it doesn't seem to work.

In my current dir:

Quote:

2007-07-07 11:36 makeobjs.c

In the dir I will copy it to:

Quote:

2007-07-07 11:40 ../../mud/src/makeobjs.c

That one is newer. Therefor, it shouldn't copy it.

So I went ahead and did cp -iu makeobjs.c ../../mud/src/
But it gave me:

Quote:

cp: overwrite `../../mud/src/makeobjs.c'?

Am I doing something wrong? It shouldn't be overwriting the file.

jschiwal · 07-07-2007, 04:02 PM

The update option (-u) will do what you want on its own.

If you needed to copy only non-existant files you could use:

cp -i *.[ch] ../../mud/src < <(yes n)

If you don't like the noise then use:
cp -i *.[ch] ../../mud/src/ < <(yes n) 2>/dev/null

This also works with the mv command, and may be needed if the --reply option doesn't exist.

Zeno McDohl · 07-07-2007, 04:20 PM

That still doesn't work. I want to copy file(s) to ../../mud/src/ only if the current file is newer. I tried

Code:

cp -i bleach.c ../../mud/src/ < <(! :)

but it still asked me to overwrite the file, even though the file wasn't newer.

colucix · 07-07-2007, 05:48 PM

Quote:

The update option (-u) will do what you want on its own.

jschiwal was right! Have you verified that answering yes do actually copy the file? Probably the shell verify if there is another file with the same name and then verify if it is newer or not.

Zeno McDohl · 07-07-2007, 05:53 PM

Okay well in that case, I don't want it to verify with me if the target file is newer. How would I do that?

colucix · 07-07-2007, 06:15 PM

I mean that using the -i option the shell prompt you with the question "overwrite...?" but even if you answer yes, the -u option avoids the copying if the source file is older than the target file (as you expected). In other words a newer file is never overwritten if you use the -u option, even if the shell make you believe that it is going to do that! ;-)

Zeno McDohl · 07-09-2007, 09:06 AM

I know that. But I don't want that. I don't want to have to be prompted for every single file (and that's a lot of files for all .c and .h files)

jschiwal · 07-09-2007, 05:50 PM

If you use "cp -u *.h *.c ../../mud/src/", only files with newer timestamps will be copied. You could see which files are copied with "cp -ul *.h *.c ../../mud/src/".

You will not be prompted at all.

I should correct my previous post however. The < <(!

part will work if you want to respond no. But not for the right reason. Use < <(yes n) if you want to reply no and < <(yes y) if you want to reply yes. You need to do this in place of the --reply= option which is being removed from the cp and mv commands.

Zeno McDohl · 07-10-2007, 12:34 PM

Quote:

You will not be prompted at all.

But that's the problem. I wanted to be prompted. But not for files that are older.

Zeno McDohl · 07-19-2007, 04:13 AM

As it turns out, the -iu problem I'm having is a bug in coreutils.