prog.cpp:20:14: warning: character constant too long for its type
file_name db 'command.com', 0
^
prog.cpp:21:14: warning: multi-character character constant [-Wmultichar]
just_file db 'file', 0
^
prog.cpp:22:14: warning: character constant too long for its type
msg_ok db 'file opened$'
^
prog.cpp:23:14: warning: character constant too long for its type
msg_err db 'error$'
^
prog.cpp:1:1: error: 'CSEG' does not name a type
CSEG segment
^