Linux and unix Commands

UNIX Command Meaning


cat --> Show the content of file.
date --> Show system date and time.
hostname -->Display name of system.
find -->Search for a specific file.
grep -->Search a file for specified pattern.
ls -->List files in a directory.
more -->Another command to show content of file.
ps -->Show status of processes.
strings -->Show strings within a file.
uname -->Show system-related information.
who -->Show current users on the system.



# who
will produce a list ofthe login names for all users presently on the system, such as
bill pts/1 Sep 9 06:41 (pebbles)
root pts/10 Sep 9 09:11 (fred)
sjmaxwell pts/2 Sep 9 08:02 (wilma)



# who am i
root pts/8 Dec 27 15:21 (dhcpclient-202)




# who -r
. run-level 3 Dec 8 10:41 3 0 S



# rm records.dat
#
is run, it removes the records.dat file and issues the shell prompt again.



# ls records.dat
records.dat: No such file or directory
#



# rm records.dat
rm: records.dat not removed: Permission denied
#



# date
directory and
filename to list
Numbers at beginning of each line are from -n
option, not part of the /etc/passwd file
-n option to number
output lines
will show output formatting like the following:
Thu Dec 27 16:59:15 PST 2001



# ping pebbles.home.com
pebbles.home.com is alive