Text 1077, 110 rader
Skriven 2004-09-11 09:21:02 av Paul Rogers (1:105/360.0)
     Kommentar till en text av Pascal Schmidt
Ärende: Is it safe to "merge"?
==============================
 PR> Oh, yeah, the once I tried to test with a non-existant source
 PR> directory and the "exit 1" on a separate line, it logged me off!
 PR> That wasn't what I expected!  Is there a fix?  Are the other
 PR> exits OK?
 PS> Huh? This shouldn't happen at all.

I didn't think so either.  I can try it again.

 PR> #!/bin/bash
 PR> #PGR: merge branches
 PR> verbose=0
 PR> if [ "$1" = "-v" ]; then
 PR>   verbose=1
 PR>   shift
 PR> fi
 PR> echo "Source directory: $1"
 PR> if [ ! -d $1 ]; then
 PR>   echo "Source directory doesn't exist. $1" ; exit 1
 PR> fi
 PS> This is not going to work if $1 contains spaces or the user
 PS> forgot to give a parameter.

I think that may have been what I tried when I got logged off,
I forget.  Does quoting $1 in the if help?  Guess I need to study
more about when "$x" means x with all its special characters, and
when it means $x.

 PR> [ $verbose ] && echo "Destination directory:  $2"
 PR> for f in `find $1 -print`
 PS> I dunno. I'd do a "find -type d" first to build the target
 PS> directory structure, if needed, then a "find -type f" to do
 PS> the files. Once again, your find command will malfunction
 PS> if $1 contains spaces. It's a good habit to always write
 PS> "$1", with the double quotes.

find gives me the parent directory node name, followed by all its
files/leaves.  If it doesn't exist in the destination tree, this gives
me the opportunity to create it.  Should I really consider that a "side
effect"?  I thought this was safer than depending on copy/move to
create the directory--still not exactly sure about that.

I need to study double quotes and single quotes, I guess.

 PR>   do
 PR>     [ $verbose ] && echo
 PR>     [ $verbose ] && echo "File/Directory: $f"
 PS> [ $verbose ] && echo -e "\nFile/Directory: $f"

OK

 PS> Though I still would prefer a simple shell function to
 PS> replace echo, makes the script much more readable.

I think so too, but looking at scripts in rc.d, et al, this
construct seems to be widely accepted.  I need to appear "with
it"!  ;-)

 PR>     d=${f/$1/$2}
 PR>     [ $verbose ] && echo "Destination: $d"
 PR>     if [ -d $f ]; then
 PR>       [ $verbose ] && echo "$f is a directory."
 PR>       if [ ! -d $d ]; then
 PR>         [ $verbose ] && echo "$d doesn't exist, making it."
 PR>         mkdir $d || exit 2
 PS> Testcase: have $d exist, but as a non-directory. Should
 PS> work with your code, though.

Directory in the source, file in the destination?  Euww.  I don't
know what to do besides give up (exit 2).  Is there something else
I should do?  (This command OR construct is another one an old
FORTRAN progeammer has a hard time getting used to.)

 PR>       fi
 PR>     else
 PR>       if [ -f $f -a $f -nt $d ]; then
 PR>         [ $verbose ] && echo "Copying $f to $d"
 PR>         cp -f $f $d || exit 3
 PS> If $d ends up being an existing directory, this will copy
 PS> $f *into* the directory.

As long as $d isn't a newer file, that's just the sort of copy
I want.  I'm trying to build up my /pub directory, copying file
trees to the server, then merging them into one tree.

 PR>       else
 PR>         [ $verbose ] && echo "Source $f is older than destination $d"
 PR>       fi
 PR>     fi
 PR>   done
 PR> echo "All done."
 PS> Looks good apart from the fact that spaces inside any of
 PS> the filenames will screw you up. For example, d="my
 PS> directory" will result in directories "my" and "directory"
 PS> being created.

The source trees are coming from downloads on my Windows box,
that's going to happen!  Perhaps a tr on d$ making " " into "_"?
Or quoting f$/d$?  I never anticipated this.

Thanks for your comments.  You saved me from a big mess.

Paul Rogers, paulgrogers@yahoo.com                       -o)
http://www.angelfire.com/or/paulrogers                   /\\
Rogers' Second Law: Everything you do communicates.     _\_V

... Searching for light in the darkness of insanity.
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 * Origin: The Bare Bones BBS (1:105/360)