man -k [key word]       find manual for command related to a keyword
export VAR=value        'set' a command shell environment variable
                        ~/.profile     user shell commands/variables
                        /etc/profile   global system shell commands/variables
grep -i foo foo.txt     report string foo matches in file foo.txt
set REQUEST_METHOD POST	Example of how to set an environment variable
			... use set to view state
talk willco@inow.com	live chat session, ctrl C to quit
.forward		place this file containing a forward
			address in home directory. chmod 644?

mail
  q		quits and deletes read messages
  pre *		will unread all messages such that quit does not delete them
  w n [file]	saves message body only
  s n [file]	saves entire message 
  x		quits with no message deletion

useradd -u UID -d /home/username -c "User Name" username -m
passwd [opt user]		change password, defaults to current user
passwd -l username		lock out user
passwd -S username		report user password status
smbpasswd user:user		update SMB (MS Windows file sharing) passwd
adduser username		will ask for full user name
gpasswd -a rickatech public	add user to existing group
usermod -a -G public henauker	add user to existing group
groupadd -g GID groupname

pwd			show current file path
rm -R [path/file]       will summariliy delete dir and its children
rm -fr ...              recursive and skips user prompts
cp -a old new           preserve file properties i possible 
chmod 760 [file/dir]	rwx, rw, -
chown [user].[group]
chmod g+s [dir]		new child dir's will inherit parent group
			Users and Groups
grep -i foo foo.txt	report string foo matches in file foo.txt
ps			list your active processes
ps ax			list all active processes
ps axjf			tree list all active processes
kill [p#]		kill active process by number
kill -n 9 [p#]		kill hung process by number (SIGKILL)
gzip [file1]		compress to file.gz
gunzip [file1.gz]	uncompress to file1
tar cvf [archive] *	create archive file of all files in current directory
tar xvf [src]		extract files from archive
zip -r foo.zip set/*
bzip2 -d foo.bz2
uuencode [src] [name] > [dest]
uudecode [file]
du			recursive directory showing block use
ln [org] [lnk]		make a hard file link
ln -s [org] [lnk]	make symbolic link
foo &			runs foo as background task
tr '\r' '\n' < in > out Macintosh -> UNIX
tr -d "\r" < in > out   MSDOS-> UNIX
history -c		wipe shell history (best performed right before exit)

vi
  /			locate text forward
  ?			locate text reverse
  ma			mark block start
  mb			mark block end
  :'a,'bd		delete block
  yy                    copy line
  P                     insert line below
  G                     move to last line
  :0                    move to first line
  :set nowrap           don't wrap long line, set wrap to enable
  :set ic               ignore case for locate text
  :set noic             use case for locate text
  :sp [file]		split screen, specify different file
			ctrl W to switch between split screens

find [path] -name [file]
find -iname "*.c" -exec grep -i "foobar" -H -n {} \;

df			show disk space usage
diff -b [f1] [f2]       show non-white space differences between files
tail -f [file]		watch file being appended, ^C to end
watch ls -l		2 second refresh of ls command
uname -a		report system information
lsmod			list kernel modules currently active

Helpful DNS diagnostic commands (typically part of bind-utils package) ...
whois zaptech.org
dig jabber.zaptech.org
dig jabber.zaptech.org any
dig @ns1.sparkworx.com jabber.zaptech.org

su -			invoke root shell w/root environment
date -u			output UTC time instead of local time
a2ps -Plp192.168.11.21 foo.c
scp RPMS/apache-1.3.20-16.i386.rpm fredness@tester.local:/home/fredness
killall httpd
nohup ./httpd &		from terminal session, invoke command in background (creates nohup.out)

ci foobar.txt		RCS commit
co -l foobar.txt	RCS checkout
rlog foobar.txt		RCS show commit log
rcsdiff foorbar.txt	RCS diff current vs last commit
rcsdiff foorbar.txt 1.1 1.2

w			show who's logged in
netstat -l              what is listening
netstat -a              what is listening and sending
netstat -tp             show process id of tcp connections

cat /proc/ide/svwks     machine technical attributes
hdparm -i               hard disk technical attributes

.htaccess		this file declares server side include
			and MIME type extensions served

# IP6 ping, require specificying interface
  ping6 -I eth0 -c fe80::20c:29ff:fe13:c50f

# show all filenames, for each name if present also cat the file
  find . -name "*" -exec sh -c "echo file:{} && cat {}" \;

# show files older than 60 days
  find . -atime +60 -exec sh -c "ls -l {};" \;

# fancy ftp handling, may not be part of most distros base install
  ncftpget -d stdout -u username -p passwd -R ftp://somesite.com/public_html

# test pulling slave data from a DNS master
  dig axfr @pentium.lan.zaptech.org zaptech.com

# recursive ftp download using username with a '@'
  wget -r ftp://leighster%40sprintmail.com:password@ftp-www.earthlink.net

# wget, another recursive example
  wget ftp://bubble/httpdocs/* -r --user bubble --password pop

# copy a file, then use sed to find/replace string, e.g. '<' -> '&lt;'
  cp foo baz; sed -i -e 's/</\&lt;/g' baz

# Find all files with name Root, search and replace text
  find -name Root -exec sh -c "sed -s s/happy-neuron.com/63.131.132.56/g {} > sed; mv sed {}" \;

Elsewhere Links [ edit ]

• UUSB / Physics Department: Running UNIX shell commands from vi

tablet | printable