chmod

Options: noop verbose

Changes permission bits on the named files (in list) to the bit pattern represented by mode.

mode is the symbolic and absolute mode can be used.

Absolute mode is

FileUtils.chmod 0755, 'somecommand'
FileUtils.chmod 0644, %w(my.rb your.rb his.rb her.rb)
FileUtils.chmod 0755, '/usr/bin/ruby', :verbose => true

Symbolic mode is

FileUtils.chmod "u=wrx,go=rx", 'somecommand'
FileUtils.chmod "u=wr,go=rr", %w(my.rb your.rb his.rb her.rb)
FileUtils.chmod "u=wrx,go=rx", '/usr/bin/ruby', :verbose => true

"a" is user, group, other mask.
"u" is user's mask.
"g" is group's mask.
"o" is other's mask.
"w" is write permission.
"r" is read permission.
"x" is execute permission.
"s" is uid, gid.
"t" is sticky bit.
"+" is added to a class given the specified mode.
"-" Is removed from a given class given mode.
"=" Is the exact nature of the class will be given a specified mode.