UNIX for Dummies Questions & Answers

I have files inside the some directories. The no. of files in each directory will vary from 1 to 500K. I need to change the permissions of all the files to 400 mode. When the files are large in numbers...the command
$chmod 400 *
fails saying "ksh: /bin/chmod: arg list too long"

so I have written a small script to do it.... like
for i in `ls`
do
chmod 400 $i
done

This script is changing the files to 400 mode, but it is taking a lot of time to complete as it has to loop through the for loop many times especially when the files are 100K or more. Is there a faster way we can do this?

Thanks for your help
-------------------------------------------
Also can anyone help me in writing a script to recursively traverse a directory and change all files to 400 and all subdirectories to 755 permissions.

use find and xargs to solve this problem...

Code:

find starting-directory -type f | xargs -n 10 chmod 400

the find will print out the paths to all the files

xargs will batch these up 10 at a time (see the -n 10) and run "chmod 400 filelist" where filelist is the list of file paths.

Porter,

Thanks for your help. This worked... now it is faster.... Can we add chainging directories also to 755 in the same command or do we need to execute seperately one more command for chaging the directories. like
find <dir> -type d |xargs -n 1000 chmod 755

thanks again.

Absolutely!

I run the below command

Code:

(find <dir> -type d | xargs -n 100 chmod 755) |tee -a logfile 2>&1

But it was not able to search in one of the directories...and it printed it on screen saying
find: cannot search dir/dir1/dir2
find: cannot search dir/dir1/dir3

But this information was not captured on the logfile. How do I capture this info in the logfile as well as print it on the screen.

Rather than using "tee" I tend to write all to a log file then run another session that does "tail -f logfile" if I want to watch it.