F.1. adminpack
  
   adminpack
  
  provides a number of support functions which
  
   pgAdmin
  
  and other administration and management tools can
  use to provide additional functionality, such as remote management
  of server log files.
  Use of all these functions is only allowed to the superuser by default but may be
  allowed to other users by using the
  
   GRANT
  
  command.
 
The functions shown in Table F.1 provide write access to files on the machine hosting the server. (See also the functions in Table 9.94 , which provide read-only access.) Only files within the database cluster directory can be accessed, unless the user is a superuser or given one of the pg_read_server_files, or pg_write_server_files roles, as appropriate for the function, but either a relative or absolute path is allowable.
   
    Table F.1. 
    
     adminpack
    
    Functions
   
  
| Name | Return Type | Description | 
|---|---|---|
| 
        pg_catalog.pg_file_write(filename text, data text, append boolean)
        | 
        bigint
        | Write, or append to, a text file | 
| 
        pg_catalog.pg_file_rename(oldname text, newname text [
        
         , archivename text
        
        ])
        | 
        boolean
        | Rename a file | 
| 
        pg_catalog.pg_file_unlink(filename text)
        | 
        boolean
        | Remove a file | 
| 
        pg_catalog.pg_logdir_ls()
        | 
        setof record
        | List the log files in the 
        log_directory
       directory | 
  
   pg_file_write
  
  writes the specified
  
   
    data
   
  
  into
  the file named by
  
   
    filename
   
  
  .  If
  
   
    append
   
  
  is
  false, the file must not already exist.  If
  
   
    append
   
  
  is true,
  the file can already exist, and will be appended to if so.
  Returns the number of bytes written.
 
  
   pg_file_rename
  
  renames a file.  If
  
   
    archivename
   
  
  is omitted or NULL, it simply renames
  
   
    oldname
   
  
  to
  
   
    newname
   
  
  (which must not already exist).
  If
  
   
    archivename
   
  
  is provided, it first
  renames
  
   
    newname
   
  
  to
  
   
    archivename
   
  
  (which must
  not already exist), and then renames
  
   
    oldname
   
  
  to
  
   
    newname
   
  
  .  In event of failure of the second rename step,
  it will try to rename
  
   
    archivename
   
  
  back
  to
  
   
    newname
   
  
  before reporting the error.
  Returns true on success, false if the source file(s) are not present or
  not writable; other cases throw errors.
 
  
   pg_file_unlink
  
  removes the specified file.
  Returns true on success, false if the specified file is not present
  or the
  
   unlink()
  
  call fails; other cases throw errors.
 
  
   pg_logdir_ls
  
  returns the start timestamps and path
  names of all the log files in the
  
   log_directory
  
  directory.  The
  
   log_filename
  
  parameter must have its
  default setting (
  
   postgresql-%Y-%m-%d_%H%M%S.log
  
  ) to use this
  function.