MA10126
Introduction | Logging in | Directories | Files | Text Editors | Miscellany | File access | Links
6. Miscellany
Here are a few other
commands which may be useful…
We saw the command who
which produces a list of all users currently logged onto the Unix service. If
you see that your mate mapjkl is logged on, you can invite him to chat by the
command
write mapjkl
This will send a message to
his screen. If he responds, you can chat by instant messaging until you
terminate the conversation by pressing ctrl-d.
If you don’t want to be
interrupted by such invitations to chat, issue the command
mesg n
No such messages will be passed
to you, until you exit or become available again by typing
mesg y
If you try to open a Unix
text file using a Windows application such as Notepad, you will find that the
line breaks are missing. There is a command to convert a Unix file to Windows
(Dos) format:
unix2dos datafile
> data.txt
will produce the file data.txt
in Dos format from the Unix file datafile.
To go the other way, there
is the command dos2unix
If a file such as prog
is executable, e.g. it is a program, you can run it in Unix by just typing the
program name:
prog
By default, it will expect
any data input to come from the keyboard. If you want it to read the data from
the file datafile, type
prog < datafile
By default, the program
output will appear on screen. To send the output to a file, use the >
feature:
prog < data
> outputfile
When you try to run a
program or command and the screen seems to “hang”, this is often because the
system is waiting for input from the keyboard, instead of from a datafile.
To be able to execute a
file, you first have to set the necessary permissions. The next page deals with
this; click on the “File access” link in the linkbar below…
Introduction | Logging in | Directories | Files | Text Editors | Miscellany | File access | Links