maintained by Mac-arena the Bored Zo, [email address that no longer works] copyright 2003 Mac-arena the Bored Zo available from [URL no longer works] HTML/PHP version at [URL works but no longer has a mirror] MIRRORS WELCOME! please email me if you want to mirror. some commands submitted by Steve Leopardi [email address deleted], frost, and rajnchaos Linux Cheatsheet IS NOT PUBLISHED BY IDG BOOKS and anyone who says it is is an idjit. :) IDG publishes the "Cheat Sheet" line of books - note the space. Cheatsheet and the Cheat Sheets are unrelated.
- listings are useful to root (or limited to root).
cmd = command or windows key opt = alt, option, or meta key sft = shift key ctrl or ^ = ctrl l prefix = left (e.g. left shift) r prefix = right (e.g. right shift)
- = press these together (e.g. cmd-q = hold cmd & Q together, then release both , = press in order (e.g. press ctrl-x, then ctrl-c)
clear = clear screen and put prompt at top command command args = run command w/ args as its parameters, ignoring aliases date = put system date to stdout (\d in $PS1 is recommended instead) *rdate server = sync clock with server via NTP (I recommend tock.usno.navy.mil) *uptime = put how long the system has been up to stdout *free = how much memory is available
bash = Bourne Again SHell pdksh = Public Domain Korn SHell (aka ksh) tcsh = TENEX C SHell sh = bourne SHell zsh = Z SHell mc = Midnight Commander - not CLI, rather like DOS Shell actually pilot = Pine's Internal Lister of Things - simpler than mc; included w/ pine
nslookup host = resolve host (could be either a hostname or IP) nslookup host DNS = resolve host using given DNS ping host = send an ICMP ping to host whois hostname = whois this hostname (rs.internic.net)
*shutdown -h now = shutdown immediately *shutdown -r now = shutdown and restart immediately *shutdown -h/-r minutes = shutdown and restart in minutes
*who = see who is on the system write person = send a message to person (ctrl-D to end) mesg boolean = set whether you can be written to (y or n) login = login again (does not kill your previous shell) su = same as above with "root" for username logout = logout and disconnect your session exit = quit the non-login and/or Korn shell (same as kill -9'ing its PID)
username:passwd*:UID:GID:finger name:home dir:shell usually just ''; passwords are stored elsewhere
cd folder = switch to folder
folder = /folder = folder "folder" at the top level
folder = folder = folder "folder" in .
folder = . = current folder
folder = .. = folder that is one level higher
folder = ~ = home directory (as defined in $HOME)
folder = ~user = user's home directory
these can be combined, as in '/boredzo/src/../bin/./emacs', or ksh $(pwd) in $PS1 instead)
pwd = put working directory (use sh \w, csh %
ls -AdFkl folder = show infomation on folder (which of course could also be a
file)
ls -ABCF = multicolumn list of all files, folders, and links except . and ..
ls -ABFkl = long (1-col) list of all files, folders, and links except . and ..
ls -Al|wc -l = count files/folders
ls -Al folder|wc -l = count files/folders in folder
touch -r file time = set modification date of file to time (now if omitted)
chmod user[+-=]permissions file = set permissions for user of file to
permissions (see Symbolic Permissions below)
chmod octal file = set permissions of file to octal (see below)
chown user file = give file to user - to get it back they must give it back!
chown user:group file = give it to group as well
mv file file = rename file1 to file2
mv file folder = move file to folder
mv file folder/file = move file1 to folder, then rename it to file2
cp source dest = copy source to dest (e.g. cp ~/risebox/cheatsheet.txt ~)
cp -a source dest = exact copy
ln -s source target = create a symbolic link (alias, shortcut) to source at
target
ln source target = create a hard link - needed for applications
grep pattern = search for pattern in the text piped to grep (see below)
grep -f file = search for the patterns in file in the text piped to grep
cat file1 file2 = append file2 to file1 and put the result to stdout
cat file = display file uninterrupted
less -M file = display file (see below for paging cmds)
less -M = display whatever is piped to less
head file = display the first 10 lines of file
tail -f file = display the last 10 lines of file, adding as the file grows
wc -l file = count lines in file
wc -w file = count words in file
wc -c file = count characters in file
du -b file = file size for file in bytes
du -k = ...in kibibytes
du -BM = ...in mebibytes
u = user who owns the file g = group that owns the file o = Public At Large (others) a = all of the above
- = add given permissions, ignore others
- = revoke given permissions, ignore others = = set permissions absolutely (add specified perm's and revoke any others) r = read w = write x = execute s = user/group ID bit; process owner == file owner (instead of the user opening the file) t = sticky bit; contents stay in memory until pushed out by disuse chmod a=rwx,o-w file.txt = sets permissions of file.txt to rwx for file owner and his group, but only rx for anyone else chmod a=rwx,o-w,u+s file.txt = sets permissions of file.txt as above, but anyone who runs it will have the same access as the file owner (IOW, file owner = process owner) - so watch out if owner is root octal is usually more efficient, and NEVER set your shell +s! this gives anyone with an account root access without being root!
down = permission across = position in octal number (from right) 1 2 3 4 1 o+x g+x u+x o+t, sticky bit (prog is cached in RAM; faster reload) 2 o+w g+w u+w g+s, if g+x, group ID (group=process owner), else lock 4 o+r g+r u+r u+s, if u+x, user ID (file owner = process owner) total number at left to get permission to set - a=rwx is 777; u=rwx,o=r is 704 add 4th digit for sticky/[UG]ID bits, e.g. a=rwx,u+s = 4777
alias name=value = alias name to value (typing name then executes value) alias name = display the alias name unalias name = delete alias typeset -x variable=value = set variable to value variable=value;export variable = same as above export variable=value = same as above typeset = show environment (all variables) set = same as typeset env = same as typeset, but doesn't show as many
\d = date \h = machine name \H = entire hostname \n = newline ! or # = how many cmds you've executed so far (including login and this one) \s = the name of the current programme, i.e. the shell \t = time (24-hr) \T = time (12-hr) - bash 2.0 only @ = time (AM/PM) - bash 2.0 only \u = $LOGNAME \w = working directory \ = backslash () \nnn = the character expressed by octal nnn (see ASCII character list below)
%d %w %D = date (same as bash \d; add %Y for year) %m = machine name %M = entire hostname %B and %b = begin/end boldface %U and %u = begin/end underline %S and %s = begin/end inverse (standout mode) %! or %h = how many cmds you've executed so far (including login and this one) %T = time (24-hr) %P = time (24-hr w/ secs) %t or %@ = time (12-hr) %p = time (12-hr w/ secs) %n = $LOGNAME %~ = working directory (equivalent to bash) %c0n = last n (default 1) segments of the working dir; if 0 is present, replace missing parts with "/skipped" e.g. "/skipped/boredzo" %% = percent sign (%) \nnn = the character expressed by octal nnn (see ASCII character list below)
...has no PS1 variables. use command or variable substitution instead (see Korn Shell Script below)
ps = show all open processes ps aux|grep pattern = list all processes matching pattern nohup command = execute command without killing it on logout kill PID = kills (terminates) the process marked PID (according to ps) *kill -9 PID = force-kills the process marked PID (according to ps) using SIGKILL - equivalent to Mac cmd-opt-esc or DOS ctrl-alt-del the process does not get to clean up after itself; USE WITH CAUTION!!! you can (and very probably will) lose data this way! screen command = start screen and execute command within it (sort of a shell) ctrl-A,d = detach a process launched with the above method screen -r = reattach all processes bkgnd'd with the above sequence (to detach = to suspend output to stdout; reattach = resume it again) (this effectively "hides" an application, and in a lot of cases can be better than command &) command & = executes command and backgrounds it fg = resume all suspended (&'d) cmds crontab -e = edit your crontab schedules
test -e file = file exists test -x file = ...and is executable test -w file = ...writable test -r file = ...readable test -s file = ...not empty test -d file = ...a directory test -f file = ...a regular file (not a device driver or directory) test text1 = text2 = test whether text1 is the same as text2 (string) test text1 != text2 = test whether it isn't (string) [ expression ] can also be used instead of test expression Korn shell recommends you use [[ expression ]] instead of either break = exit from a loop echo text = display text on the screen echo -n text = display text but don't put a newline after it echo -e text = display text and look for these wildcards: \n = newline \t = tab \a = alert (system beep character, ctrl-g - see ASCII character list) \0nnn = character with octal value nnn (see ASCII character list) \ = a backslash print text = same as echo -e, for ksh (use print -r to emulate echo) print -un text = print to file descriptor n (ksh only) print -r text = print to file descriptor n (ksh only) read variable = assign 1 line of user input to $variable if commands then commands elif commands then commands else commands fi = determines the result of a command(s) and executes other commands based on it (elif and else are optional) case text in pattern) commands;; pattern) commands morecommands;; ... esac = determine whether text matches pattern, pattern, etc. and act on it (often used with read for a prompt)
. = any character except \000 ("") or \n (newline)
- = 0 or more times
- = 0 or 1 times ? = 1 times [characters] = any of characters ^ (at beginning of character class) = all BUT the chars in the class
- = range (e.g. [0-9a-zA-Z] searches for all alphanumeric chars) (pattern) = search for a subpattern (e.g. [(fools)(fool's)] gold) \ = escape character (don't parse it) - e.g. . searches for a period ^ (at beginning of pattern) = search only at start of line $ (at end of pattern) = search only at end of line {number} = number instances of preceding char, separated by commae {,number} = no more than number instances {number,} = no fewer
b = go backward one screen f = go forward one screen space = same as f up = go backward one line down = go forward one line e = launch $EDITOR (usu. ed) v = launch $VISUAL (def. vi, but emacs recommended) p,percentage = go to percentage of the file /,pattern = search for pattern
archive = the archive to make from original = the file or folder to compress tar -czf archive original = tar and GZip zip -mR9yT archive original = zip (Windows)
archive = the archive to decompress tar -xzf archive unzip -tX archive
pine = start pine and go to the main menu pine addr = start pine with a blank message to addr, and quit when it's sent/canceled
c = create new outgoing message l = folder list a = address book
- = backward (up) one screen space = forward (down) one screen d = mark item for deletion u = unmark item for deletion r = reply to it f = forward it to someone else < = previous list or menu return or enter or > = view it tab = select next new message c = compose new message
N = new; hasn't been read (nothing) = has been read A = has been read and/or replied to (i.e. answered)
- = bwd one screen spc = fwd one screen v = view attachment list
ctrl-x = send message ctrl-c = cancel and dispose of message (w/o sending) ctrl-j = attach file(s) ctrl-y = bwd one screen ctrl-v = fwd one screen ctrl-k = cut to end of line (same as emacs ctrl-k) ctrl-u = uncut (same as emacs ctrl-y)
vi = start vi with an empty buffer and no open files vi file = open file for editing
i = input mode esc = command mode :se number = display line numbers :se nonumber = don't display line numbers :e = open file :w = save (write) file to disk :wq = save and quit :q! = quit but don't save number,command = apply command number times (e.g. 4,x = delete 4 characters) . = repeat last effective cmd esc,u = undo it
- = go to beginning of previous line 0 (zero) or ^ = go to beginning of this line $ = go to end of this line ret or + = go to beginning of next line (NOT THE SAME AS INPUT RETURN) w = go to beginning of next word b = go to beginning of this word e = go to end of this word sft-h = go to first line onscreen sft-l = go to last line onscreen ctrl-f = forward (down) one screen ctrl-b = backward (up) one screen 1,sft-g = top of the buffer sft-g = bottom of the buffer (i.e. EOF) :line = go to line (e.g. :35 = go to line 35) column,| = go to column (e.g. 4,| = column 4)
deleted text is put to the general purpose buffer; use the p cmd to retrieve it you can also use yanks to not delete it but still put it in the GPB basically delete = cut and yank = copy in your OS's Edit menu x = delete this character d,w = delete word d,d = delete line sft-d = delete to end of line (same as emacs ctrl-k) y,w = yank to beginning of next word sft-y or y,$ = yank to end of line y,y = yank entire line buffer"lines"y,y = yank lines number of lines into buffer buffer (a-z) p = paste contents of general-purpose buffer
to use replacers type the sequence and then type the string of characters to replace with, e.g. 2,c,w,"Bored Zo" to replace from the cursor to the end of the next word to "Bored Zo" r = replace a single character shift-r = replace characters from the cursor(e.g. if | is the cursor and your text is "I AM the |Entertained Zo!" shift-r,"Bored" will give you "I AM the Boredtained Zo!") c,w or c,e = change from cursor to end of word c,b = change from beginning of word to before cursor c,$ or sft-c = change from cursor to end of line c,c = change the ENTIRE line :x,ys/oldstring/newstring/ = substitute newstring for oldstring from line x to line y (if y = $ then to EOF) ~ = toggle a character's case
see section on regular expressions above / = search forward from cursor for a pattern ? = search backward from cursor for a pattern n = next result sft-n = previous result
o = insert a blank line below this one sft-o = ...above this one :r file = insert file at cursor
note that you can usually use opt- instead of esc, and each binding will still work. e.g. opt-esc,esc = cancel (like ctrl-g), opt-x = summon command prompt emacs - Shell prompt emacs = start emacs with one empty buffer and no open files emacs file = open file for editing emacs file +number = open file and scroll to line number ctrl-x,ctrl-c = quit
ctrl-x,ctrl-f = open file and create a buffer for it ctrl-x,b = switch buffers (default is the next) ctrl-x,k = kill (close) buffer and file ctrl-x,0 (zero) = kill window ctrl-x,1 = kill other window(s) ctrl-x,2 = spawn new window under this one ctrl-x,3 = spawn new window to the right of this one ctrl-x,o (oh) = switch to other window
arrows = move cursor 1 character in any of the 4 cardinal directions - horizontal position in the line is maintained when you move u/d esc,f = fwd (right) one word esc,b = bwd (left) one word ctrl-a = move to start of line ctrl-e = end of line esc,r = move to window line (?!) ctrl-v = fwd (down) one screen (typically 22-24 lines) esc,v = bwd (up) one screen ctrl-x,] = fwd one page (defined by lpd?) ctrl-x,[ = bwd one page esc,< = top of buffer esc,> = bottom of buffer
ctrl-t = transpose this character and the previous esc,t = transpose this word and the next or previous depending on position in word ctrl-x,ctrl-t = transpose this line and the previous esc,c = properly capitalises the word (Like this) ctrl-x,ctrl-l = decapitalises the selection esc,l = decapitalises the entire word (like this) ctrl-x,ctrl-u = capitalises the selection esc,u = capitalises the entire word (LIKE THIS) ctrl-spc = set mark ctrl-w = cut selection (text from mark to cursor) to kill buffer (clipboard) esc,w = copy selection ctrl-y = paste ("yank") contents of kill buffer to working buffer
ctrl-s = search fwd (down) from cursor ctrl-r = search bwd (up) from cursor esc,ctrl-s = search fwd from cursor using a regular expression (see above) esc,ctrl-r = search bwd from cursor using a regexp esc,sft-ctrl-5 = replace fwd from cursor using a regexp ctrl-g = cancel ! = replace all from cursor and including this hit ? = help . = go back to where search started and exit replace y/spc = replace and continue n = don't replace but continue
anything you delete is put to the kill buffer - up to kill-buffer-max (def. 30) can be in the kill buffer at any one time ctrl-y = yank last (most recent) item in kill buffer esc,y = substitute just-yanked text for next-to-last item in kill buffer ctrl-d = delete this character (same as fwd-del) del = delete previous character esc,d = delete next word ctrl-w = wipe (kill) selection and put it to kill buffer (see above) ctrl-k = kill everything from cursor to end of line (eol)
rectangles are defined with the mark as one corner and the insertion point as the other ctrl-x,r,k = kill (cut) ctrl-x,r,d = delete (clear) ctrl-x,r,y = yank (paste) ctrl-x,r,c = blank: replace chars within w/spaces
m = make a new message in sendmail mode in second window g = check email esc,x,rmail = start rmail mode and check email emacs -f rmail = ...from the shell h = list your email ctrl-opt-t = ...that have a certain subject opt-`,sft-s,s = ...that were sent by a certain entity ctrl-opt-s = ...that match a regexp opt-p = read previous message opt-n = read next message sft-, = read first message sft-. = read last message number,j = jump to numberth message
. = top of message spc = fwd one screen bksp = bwd one screen
d = flag this message for deletion u = unflag it x = delete all flagged messages ctrl-o,filename = save this message to filename (ASCII text)
ctrl-x,m = new message ctrl-x,4,m = ...in another window ctrl-c,ctrl-w = paste the .signature file here ctrl-c,ctrl-c = send this message ctrl-x,ctrl-k = cancel it ctrl-x,ctrl-c = ...and quit
ctrl-opt-q = indent expression intelligently (just use tab, it's easier) ctrl-c,ctrl-e = expand cpp macros (might be handy for debugging) opt-`,c,u = seek comments which eat the region and remove the region from them
gdb executable = start gdb and load executable l = list the 10 lines around main(){ l = list the next 10 lines b linenum = (break) stop execution at linenum r = (run) start execution s = (step) move forward one line, even into functions* n = (next) step, but not in functions l = list 4.5 lines on either side of current line nostop = don't pass signals onto the program (don't stop it) pass = pass the signal on anyway, but nonetheless, don't kill the program *only your functions, not library ones
gcc files.c -o executable -g = compile a test C version for gdb gcc files.c -o executable -O2 = compile a final C version fully optimised* gcc -c file.c = compile file.c but don't link it into an executable; useful for make** g++ files.c -o executable -g = compile a test C++ version for gdb g++ files.c -o executable -O2 = compile a final C++ version fully optimised* g++ -c file.C = compile file.C but don't link it into an executable; useful for make** strip -s objfile = remove symbols to free up disk (bad for debuggers) *note that optimisation tends to alter the flow of the program and makes it very hard to debug, and code compiled with debugging and optimisation can even run a THIRD way. **see Programming - make
make = compile a program by the Makefile in . make target = look for Makefiles containing the target and make that only make -f makefile = use specified makefile make -n target = fake make; echoes commands to stdout instead of executing them make -j target = multiple jobs simultaneously
#text = comment target: dependencies = rule: target requires the files dependencies command = executes the command after the tab character if the above rule is met
VPATH = dir1:dir2... = other dirs to seek files
CC = compiler = redefine default compiler
name = value = custom macro definition