The command chmod 755 file is equivalent to chmod 0755 file If we run this command on a file which has the SETUIDbit or SETGIDbit set, it will remove the SETUID/SETGIDbit chmod x file will leave the SETUID/SETGIDbit untouched We ls l new_ filetxt We want the user dave to have read and write permissions and the group and other users to have read permissions only We can do using the following command chmod u=rw,og=r new_filetxt Using the "=" operator means we wipe out any existing permissions and then set the ones specifiedAdditionally, if you know php runs as the user and not as "apache", then you can set php files to 600, for an extra level of security, eg
Chmod 755
