batch file for chmod's?

teodavinci · 08-13-2004, 02:24 PM

I am doing a bunch of chmod's to various files on my red hat 7.3 system. is there a way i can create a batch file to run them all at once? If so, how do i accomplish this? thanks in advance for any input.

Dark_Helmet · 08-13-2004, 02:50 PM

You might not need a batch file; you might be able to do it all with one command. Say you have a directory that contains mp3 files organized into subdirectories (artist, album, whatever), and the top directory is /usr/local/share/music. Now, let's say you wanted to make all of the mp3's readable by everyone. You could do this:
find /usr/local/share/music -type f -name "*.mp3" -exec chmod 644 {} \;

'-type f' => only select regular files
'-name "*.mp3"' => only select files with .mp3 extension
'-exec' => execute the following text as a command until you reach '\;'
'chmod 644 {}' => change the permission of the file found. {} is replaced with the matching file.

So now everybody can read those files, but you also need to make sure they can browse to the directories:
find /usr/local/share/music -type d -exec chmod 755 {} \;

'-type d' => only select directories

That will give everone read/execute permissions for the directories so they can list the contents and read files within, and give the owner read/write/execute.

Find is a great command, but if that isn't what you're looking for, I can help with creating a shell script. I'd need need more info on what exactly you're trying to accomplish (relationships between files/directories and things like that).

You can always use a brute force method by opening up a file, and typing all the commands one by one, and then telling bash to execute them (similar to a traditional windows batch file), but that's not saving you any effort as opposed to typing them all in at the command line.

amfoster · 08-13-2004, 02:55 PM

If everything is in one directory, then maybe something very simple such as

for i in *.mp3
do
chmod 755 $i
done

or even chmod 755 *.mp3

Disillusionist · 08-13-2004, 03:04 PM

You could write a shell script to perform the chmod's

vi ~/my_chmod

Code:

#!/bin/sh
# 1st parameter is chmod code to be used
# 2nd parameter is a file containing the files to be altered
#
if [ $# -ne 2 ]
then
   echo "Syntax: $0 {permissions} {file listing}"
   exit 1
fi

l_chmod=$1
l_list=$2
cat $l_list|while read l_file
do
   if [ -f $l_file ]
   then
      if chmod $l_chmod $l_file
      then
          echo "permissions for $l_file have been set"
      else
         echo "problem setting permissions: $l_chmod to file: $l_file"
      fi
   else
      echo "$l_file not found!"
   fi
done

make it executable:
chmod 700 ~/my_chmod

Then create a driver file:
vi ~/driver

Code:

/tmp/file1
/tmp/file2
/tmp/file3

To run this script:

~/my_chmod 700 ~/driver