Why can't I use bash to do this ?

naihe2010 · 10-30-2005, 02:47 AM

I edit a scrit, and it has two word like these :

Code:

for temp in 'ls -d */'
do
cd $temp
done

But ,when I run it ,it always divided the for code like :

Code:

cd ls
cd -d
cd */

Why ?

zhangmaike · 10-30-2005, 03:00 AM

Because you're using the wrong quotation mark. What you're looking for is the backtick: ` not the single quote: '

If you want something easier to discern, you can use $() instead. It does the same thing, and also supports nesting, which the backtick does not.

So:

Code:

for temp in `ls -d */`
do
      cd $temp
done

or

Code:

for temp in $(ls -d */)
do
      cd $temp
done

or, without the command substitution, and without unnecessarily running ls:

Code:

for temp in */
do
      cd $temp
done

jlliagre · 10-30-2005, 04:32 AM

The latter:

Code:

for temp in */

doesn't works.
It should have been

Code:

for temp in */*

but that one is wrong too as it doesn't filter out non directories.

randyding · 10-30-2005, 12:07 PM

just another idea, use this one a lot

Code:

prevdir="`pwd`"
find . -type d | while read dir; do
    cd "$dir"
    # do stuff
    echo `pwd`
    cd "$prevdir"
done

zhangmaike · 10-30-2005, 01:54 PM

As for my last suggestion not working... it seems to work fine (tested it on my computer). Replacing cd with echo, it lists all the directories in the current directory.

jlliagre · 10-30-2005, 02:31 PM

You are right, my mistake, the trailing slash is indeed filtering out non directories. Sorry for the confusion.