Shell Programming and Scripting

I want to change the permission of a file when it gets created in a particular directory. For instance, I have directory MyDir. Everytime a file gets created in that directory, I would like to change the permission to 777.
The context is that I have a 3rd party appication running as root. Only root can run it. It creates a file in directory ExecDir which another account should be able to execute (say user MyUser). But by default, a file created by root has permission rwxr--r--. I cannot also touch the code of this application since it is a 3rd party tool.

I know it's absurd.. but I hit a dead end...

What OS are you running?

You will have to setup and run some process as the root user- a root crontab entry to find & chmod the files, that runs every X minutes, M-F will work

Code:

 0,10,20,30,40,50  * * * 1-5  /usr/bin/chmod  755 /path/to/files/*

You may have to get the sysadmin to set this up.

---------- Post updated at 08:00 ---------- Previous update was at 07:57 ----------

Note: you do realize the rwxr--r-- means anybody can copy the file and chmod it themselves, then execute it? As in you can write a shell script to do this.

You can setup some advanced ACLs on the directory beyond the usual ugo-permission scheme.

In Linux and older Solaris file systems, the setfacl command allows you to create some rules for all files generated in a directory
For Solaris ZFS, you need to use the chmod +A command for advanced ACLs

Here is some help with the Solaris setfacl command and I think it should mostly translate for Linux
originalFileOwner=origOwner
originalGroupOwner=origGroup
altUser=targetUser


#Sets directories back to default with no special ACL
setfacl -s u::rwx,g::r-x,o:---,m:r-x ${appDir}
setfacl -s u::rwx,g::rwx,o:---,m:rwx ${appDir}/import
setfacl -s u::rwx,g::rwx,o:---,m:rwx ${appDir}/export




#Sets directory to allow for group ${altUser} to have read/execute access to ${appDir}
setfacl -s u::rwx,g::r-x,o:---,m:r-x,g:${altUser}:r-x ${appDir}


#Sets directories to all for user ${altUser} to have read/execute access to specific directories
# Permission: u::rwx,g::rwx,m:rwx,o:--- (standard chmod-based permissions of 770)
# Permission: u:${altUser}:r-x (Sets read/write/exec permissions to directory for user=${altUser} )
# Permission: d:u::rwx,d:g::rwx,d:m:rwx,d:--- (Sets default read/write/exec permissions for files created in this directory, mirrors 'u::rwx,g::rwx,m:rwx,o:---' permission)
# Permission: d:u:${originalFileOwner}:rwx,d:g:${originalGroupOwner}:rwx (Sets default read/write/exec permissions for files created in this directory for original file owners Unix user and group)
# Permission: d:u:${altUser}:r-x (Sets default read/exec permissions for files created in this directory for user=${altUser} )

setfacl -s u::rwx,g::rwx,m:rwx,o:---,u:${altUser}:r-x,d:u::rwx,d:g::rwx,d:m:rwx,d:---,d:u:${originalFileOwner}:rwx,d:g:${originalGroupOwner}:rwx,d:u:${altUser}:r-x ${appDir}/export


#Sets directories to allow for user ${altUser} to have read/WRITE/execute access to specific directories
# Permission: u::rwx,g::rwx,m:rwx,o:--- (standard chmod-based permissions of 770)
# Permission: u:${altUser}:rwx (Sets read/write/exec permissions to directory for user=${altUser} )
# Permission: d:u::rwx,d:g::rwx,d:m:rwx,d:--- (Sets default read/write/exec permissions for files created in this directory, mirrors 'u::rwx,g::rwx,m:rwx,o:---' permission)
# Permission: d:u:${originalFileOwner}:rwx,d:g:${originalGroupOwner}:rwx (Sets default read/write/exec permissions for files created in this directory for original file owners Unix user and group)
# Permission: d:u:${altUser}:rwx (Sets default read/write/exec permissions for files created in this directory for user=${altUser} )



setfacl -s u::rwx,g::rwx,m:rwx,o:---,u:${altUser}:rwx,d:u::rwx,d:g::rwx,d:m:rwx,d:---,d:u:${originalFileOwner}:rwx,d:g:${originalGroupOwner}:rwx,d:u:${altUser}:rwx ${appDir}/import