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So I need to loop through a tree of directories, currently I can print off all the files in a directory, but once that is done I need to be able to go into the subfolders of the starting directory and so on. My Program prints off the files and the folders as a start, but I need to check each one to make sure it is a directory and then enter it. Could someone provide some guidance on this?

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migrated from Sep 29 '11 at 10:36

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help test yields

test: test [expr]


-d FILE True if file is a directory.


Exit Status: Returns success if EXPR evaluates to true; fails if EXPR evaluates to false or an invalid argument is given.

test can be abbreviated with [, so you can do

if [ -d "$file" ]; then
    # do stuff
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test -d myFileOrFolder

but what you describe looks like the behaviour of find.

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From comments entered to some of the responses I am guessing you want to run some script in each of the directory. In that case one of the possible ways is to use find with exec options as follow:

find ./ -type d -exec sh -c "cd {} && <your_script_with_absolute_path>" \;

For example, in the current dir there is a script & you want to execute it in each of the subdir in the current dir then

find ./ -type d -exec sh -c "cd {} && `pwd`/" \;

To the find command -type d will ask to look for all directories in path ./ passed as first argument. -exec will execute command for each such find, in this case sh -c which is creating a shell & executing a command with quotes, {} indicates the argument found by find command.
Hope this helps!

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Use the -d operator to test for the existence of a directory:

if [ -d "$DIR" ]; then
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Ok, that makes sense, then how would I enter that directory and run the script again? – Eric Anderson Sep 28 '11 at 12:49

Pseudo code:

[ -d your_filename ] && it's a folder ...
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then how would i enter the new directory and then call my script again? – Eric Anderson Sep 28 '11 at 12:52
find . -type d

this finds all subdirectories

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then how would i enter the new directory and then call my script again? – Eric Anderson Sep 28 '11 at 12:52
there's an -execdir option and a few others, depending on your version of find. You could also just pipe this to a while loop which explicitly visited each directory. – Foo Bah Sep 28 '11 at 15:23

Based on some of the comments, I'm guessing that you don't actually want to print the directories, but rather process all of the regular files in a directory tree (including all of the subdirectories). If that's the case, you may want to take a look at the exec option to find.

From memory, you probably want something like this (using the cat command to stand in for your script):

find . -type f -exec cat {} \;

In this example, all of the non-directory files in the entire tree (recursively) will be processed by cat (printed to standard out).

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