ken@titan ~/tmp/pm_11152251_file_rwa
$ ./read_write_append.pl

*** Test +< (r+)
Open file
Position in file: 0
Read to end of file
1
2
3
Position in file: 6

*** Test +> (w+)
Open file
Position in file: 0
Read to end of file
Position in file: 0

*** Test +>> (a+)
Open file
Position in file: 6
Read to end of file
Position in file: 6
Write a record
Position in file: 8
Rewind to start of file
Position in file: 0
Read to end of file
q
w
e
r
Position in file: 8

ken@titan ~/tmp/pm_11152251_file_rwa
$