UNIX for Dummies Questions & Answers

Hi.

I have a copy-file script (and a move-file script) that I recently tried to make interactive. I tested the former on three files from a text list, and watched to see what would happen. As the cp command was in a while/do/done loop, there was no pause for input: it wrote the file from the list to the destination directory. Casually-speaking, it "barreled right through" the list as if the -i wasn't there.

Here's part of the copy-file script.

Code:

#!/bin/bash

while read 'line';
do
n=$(echo $line)
file=${n%,*}
dest=${n#*,}
if [[ "$dest" == "" ]]; then continue; fi
echo -e "Copying $file now."
cp -ipPv $file $dest

done<copylist.txt

I know the 'pPv' options are more or less unnecessary, particularly the capital 'P', but as I write and use many of my scripts both in Cygwin and GNOME, it seems more prudent to me to include them.

In a loop such as this, would I be better off preventing overwrite (and changes of mod date, file-length, etc to the file that ended up at the destination) to write in an if/then/fi that checked for the file in the destination before copying? Something like this?

Code:

if [ -e "$dest/$file" ]; then
echo -e "Do you want to overwrite $file? (y/n)"
read arPLy
if [[ "$arPLy" != "n" ]]; then
cp -pPv $file $dest
else
continue
fi
fi

Or is there a way to introduce (I hesitate to say "force") a pause in that loop at the "cp -i" stage?

Hope someone can help and soon.

BZT

This code seems strange....

Code:

n=$(echo $line)

What is its function when n="$line" would seem on the face of it to suffice?

Code:

file=${n%,*}
dest=${n#*,}

And if you're trying to read fields splitting on "," then...

Code:

IFS="," read SRC DEST

would do all that at one blow.

Try splitting the "-i" parameter into its own parameter instead of lumping them in with 9 others.

It may also be because you redirected stdin, which would leave it unable to read interactive responses from stdin. Try this instead:

Code:

exec 5<inputfile
while IFS="," read -u5 SRC DEST
do
        ...
done
exec 5<&-

...which will leave stdin untouched for it.

Corona688:

Thanks for the help. It works great.

BZT