System information

ED also takes file attributes into account. If you attempt to edit a Read-Only file, the message
** FILE IS READ/ONLY **
appears at the console. The file can be loaded and examined, but cannot be altered. You must end
the edit session and use STAT to change the file attribute to Riw. If the edited file has the system
attribute set, the following message:
'SYSTEM' FILE NOT ACCESSIBLE
is displayed and the edit session is aborted. Again, the STAT program can be used to change the
system attribute, if desired.
2.3 Control Characters and Commands
Table 2-5 summarizes the control characters and commands available in ED.
Table 2-5. ED Control Characters
Control Character Function
CTRL-C System reboot
CTRL-E Physical <cr><lf> (not actually entered in command)
CTRL-H Backspace
CTRL-J Logical tab (cols 1, 9, 16,...)
CTRL-L Logical <cr><lf> in search and substitute strings
CTRL-R Repeat line
CTRL-U Line delete
CTRL-X Line delete
CTRL-Z String terminator
rub/del Character delete
2.2 ED Error Conditions CP/M Operating System Manual
2-19