Linux commandline tips Bash tips ^r Reverse search the command history ^a Return to the start of the command you're typing ^e Go to the end of the command you're typing ^u Cut everything before the cursor to a special clipboard ^k Cut everything after the cursor to a special clipboard ^y Paste from the special clipboard that Ctrl + u and Ctrl + k save their data to ^t Swap the two characters before the cursor (you can actually use this to transport a character from the left to the right, try it!) ^w Delete the word / argument left of the cursor ^l Clear the screen history lists command history !61 executes command on line 61 ls -l /etc/passwd stat !$ no need to repeat argument on second line man -k searches in all man pages for ls *.mp3 | xargs rm ls *.mp3 | xargs -i cp {} /home/bla ls *.mp3 -d -> stays in current dir and doesn't enter mp3/ start a restricted shell (no cd, etc) to test programs # bash -r start shell with options # bash -O [modification] autocd -> use the argument as cd command cd-spell -> corrects dir names dirspell -> corrects dir names in file completion no-caseglob -> case insensitive to run commands: # command1 && command2 logical AND :: run command1, if ok then run command2 # command1 || command2 logical OR :: run command2 only if command1 fails cp cp -rv  gives feedback cp -p preserves original date/time dd use blocks of 64k and report every 10Mb: dd if=/dev/hda | buffer -s 64k -S 10m > image or, from other console: kill -SIGUSR1 $(pidof dd) df df -type=ext3,ReiserFS df -H human readable find find all files in your homedir modified or created today find ~ -type f -mtime 0 case insentive search find . -iname "*mp3" find files and directories in yor homedir not created by you find ~ ! -user ${USER} and fix this find ~ ! -user ${USER} -exec sudo chown ${USER}:"{}" \; find duplicates PvdM find . -type f -exec md5sum '{}' ';' | sort | uniq --all-repeated=separate -w 15 free free -m -> megabytes free -t -> totals free -s[seconds] -> update interval watch the line with +/- buffers: free indicates memory that can be freed instantaniously used is all memory being used grep grep -A2 bla greps 2 lines after grep -B3 bla greps 3 lines before history # history -d [postition] -> remove specific command # history -c -> clear entire history iotop monitors io proces iotop -o makes output more readable by showing only processes causing io right now  iotop -d10 refresh interval iotop -o -b -d10 -n30 > io.txt batch mode: write io status 30 times to file at 10s interval iperf iperf -s -w128k run server for performance benchmark iperf -c   -w128k -t30 -r run client iperf -c   -w128k -t30 -d run client in two directions, full duplex kill kill -l shows instructions  1 SIGHUP restart immediately after terminating, or triggers reconfiguration of background service  2 SIGINT Ctrl+c from the keyboard, terminate!  3 SIGQUIT Ctrl+\ from the keyboard, terminate with coredump  9 SIGKILL force terminate, extreme signal that can't ignored 11 SIGSEGV program attempted an invalid memory reference, terminate with coredump 15 SIGTERM request to terminate and cleanup 19 SIGSTOP interrupts the process until you enter SIGCONT to continue kill -19 9102 10234 stops several processes killall -19 ssh sends all ssh connections to sleep killall -19 -i ssh interactive mode (recommended) lsof lsof list open files lsof -i :22 list all ssh connections (same :ssh) lsof -i@10.0.0.1 list all connections from 10.0.0.1 lsof -i@amsterdam.nl list all connections from domain lsof -u username list all open files from username lsof -c bash list open files related to bash lsof -c /log/ list all open files from all processes containing log lspci lspci -v  lspci -vv lspci -vvv lspci -nn -> show names & numerical  lspci -k -> show kernel modules associated with the device more or less +  number of line from which to start displaying z  number of lines to jump forward y   number of lines to jump back -I ignore case when searching -V underline tabs, line endings /  highlights all ocurrences of search pgrep pgrep ssh lists all ssh processes pgrep -l ssh shows names pgrep -f shows full commandline pgrep -u show user ping ping 0 -> pings localhost ping c 5 nu.nl -> pings 5 times ping -f host -> floods the host ping -a IP -> gives audible beep Note: It can give beep only from terminal number 1 through 7 and gnome-terminal ( It will not work in console ). ping -q ip -> show only summary ping -s 100 -> change packet size Pressing CTRL+| (Control key followed by pipe symbol) for the shows the summary in between, and continues with it packet sending and receiving process. ping hop1 hop2 hop3 .. hopN destination ping -R 192.168.1.63 -> Record and print route of how ECHO_REQUEST sent and ECHO_REPLY received pkill understands the same options as pgrep pkill -19 ssh pkill -19 -u joop stop joop's processes ps show how long a process is running ps -o pid,etime,cmd `pidof amarok` show memory usage per process ps -e -orss=,args= | sort -b -k1,1n | pr -TW$COLUMNS pstree pstree -a shows processes tree structure with program's parameters pstree -h highlights own process  pstree -H   highlights process id pstree -u shows user stat shows status of file stat /etc/passwd stat -c "%x %n" /etc/passwd formatted to show time swapon swapon -s see size and usage tail or head --retry keep monitoring the file  -s seconds how often monitoring retry -pid   stops tail from running if PID stops running tar tar zxf   -> extracts file top PID programma id USER gebruiker PR prioriteit van de taak NI nice value VIRT virtuele geheugen gebruik RES fysieke geheugen gebruik SHR deel v/h gebeugen dat mogelijk met andere taken wordt gedeeld %CPU percentage processorgebruik %MEM percentage geheugengebruik TIME+ de tijd dat de taak op de cpu heeft gedraaid COMMAND de naam van de taak keys: z: enable color mode. x: show sorted column in different color < >: change sorted column u [user]: show only users processes d: delay in sec show only user user #top -u user zombies ps aux | grep defunct AutoYast create autoyast file through icon in Yast2->autoyast www.suse.de/~ug (Uwe Gansert) Midnight Commander (MC) The standard colorpallette is incredibly hard to read in certain terminals, like yakuake. For readable colors (mostly black and green), enter in your ~/.mc/ini file the following line: [Colors] base_color=lightgray,green:normal=green,default:selected=white,gray:marked=yellow,default:markselect=yellow,gray:directory=blue,default:executable=brightgreen,default:link=cyan,default:device=brightmagenta,default:special=lightgray,default:errors=red,default:reverse=green,default:gauge=green,default:input=white,gray:dnormal=green,gray:dfocus=brightgreen,gray:dhotnormal=cyan,gray:dhotfocus=brightcyan,gray:menu=green,default:menuhot=cyan,default:menusel=green,gray:menuhotsel=cyan,default:helpnormal=cyan,default:editnormal=green,default:editbold=blue,default:editmarked=gray,blue:stalelink=red,default tune kernelparameters stored in /proc/sys/ gone after reboot sysctl is a service that reads sysctl.conf during boot and read parameters from there -> makes it permanent # ulimit -a givesinfo about system resources limitations