mv in for loop stops after first file it comes to

geeyathink · 02-14-2008, 06:34 AM

I saw this in a post:

Code:

#You can also use variable substitution:
#for file in *.jpg; do
#mv "$file" "${file//b/_}"
#done

And wanted to try to use it because; A. It looks simple, and B. I think its straight Bash as opposed to Perl or something.

I did this with it:

Code:

#!/bin/bash
exec 2>/tmp/script1.log
set -x

grt=`ls  /home/teabear/desktop/underfiles`

 for file in /home/teabear/desktop/underfiles/$grt  ; do
  mv "$file" "${file//_files/ }"

 done

This moves (renames) only the first folder or file it comes to in the "underfiles" folder. After that the path is lost and mv complains "cannot stat, no such file or directory" for the remaining stuff that is in the "underfiles" folder.

Here is the log file from `exec 2>'

Code:

+++ ls /home/teabear/desktop/underfiles
++ grt='b_files
d_files'
++ for file in '/home/teabear/desktop/underfiles/$grt'
++ mv /home/teabear/desktop/underfiles/b_files '/home/teabear/desktop/underfiles/b '
++ for file in '/home/teabear/desktop/underfiles/$grt'
++ mv d_files 'd '
mv: cannot stat `d_files': No such file or directory

What do I need to understand to go through and rename with mv, all the files in the "underfiles" folder, instead of just the first file it comes to?
Should my question be: "How do I supply the path for $grt to all the iterations in the for loop?"

Thank you for any help.

pixellany · 02-14-2008, 06:58 AM

The path to a variable does not make sense. When you create a variable in a shell it is available regardless of what directory you are in.

In you example, suppose that $grt = a b c. The for loop sees "/home/teabear/desktop/underfiles/a b c" This is seen as 3 filenames, but only one with a complete path.

Try:

for file in /home/teabear/desktop/underfiles/*; do....etc.

geeyathink · 02-14-2008, 07:34 AM

Thank you pixellany,

I don't know how I got off on the "path in a variable" tangent, but you have me straightened out on that. Works great.

While on the topic, I think in other parts of the script I am working on I either used or am trying to use the "path in a variable" idea just so I don't have to type as much.

Is that an always major no-no or is it ok at some times?

Thanks again for the help.

pixellany · 02-14-2008, 08:09 AM

I thought I heard "path TO a variable".....What goes IN a variable is anything you want. The trick is how a variable gets interpreted in the context in which it is used.

I'm not that swift at understanding all the rules---I usually just try things until I find what works. (I would probably not be able to make a living at programming....

)

chrism01 · 02-14-2008, 11:18 PM

Like he said, you just have to think carefully (or echo out) what you have in your variable (which can be anything you like).
A common thing to remember is that the find cmd tends to prefix all the 'filenames' with the path when it returns the files matched, whereas bare ls doesn't (but note ls -R will .. sort of)