freebsd-tips revision 235227
1This fortune brought to you by: 2$FreeBSD: head/games/fortune/datfiles/freebsd-tips 235227 2012-05-10 12:46:12Z eadler $ 3% 4Any user that is a member of the wheel group can use "su -" to simulate 5a root login. You can add a user to the wheel group by editing /etc/group. 6 -- Konstantinos Konstantinidis <kkonstan@duth.gr> 7% 8By pressing "Scroll Lock" you can use the arrow keys to scroll backward 9through the console output. Press "Scroll Lock" again to turn it off. 10% 11Can't remember if you've installed a certain port or not? Try "pkg_info 12-Ix port_name". 13% 14Ever wonder what those numbers after command names were, as in cat(1)? It's 15the section of the manual the man page is in. "man man" will tell you more. 16 -- David Scheidt <dscheidt@tumbolia.com> 17% 18Forget how to spell a word or a variation of a word? Use 19 20 look portion_of_word_you_know 21 -- Dru <genesis@istar.ca> 22% 23Forget what directory you are in? Type "pwd". 24 -- Dru <genesis@istar.ca> 25% 26Forget when Easter is? Try "ncal -e". If you need the date for Orthodox 27Easter, use "ncal -o" instead. 28 -- Dru <genesis@istar.ca> 29% 30FreeBSD is started up by the program 'init'. The first thing init does when 31starting multiuser mode (ie, starting the computer up for normal use) is to 32run the shell script /etc/rc. By reading /etc/rc and the /etc/rc.d/ scripts, 33you can learn a lot about how the system is put together, which again will 34make you more confident about what happens when you do something with it. 35% 36Handy bash(1) prompt: PS1="\u@\h \w \!$ " 37 -- David Scheidt <dscheidt@tumbolia.com> 38% 39Having trouble using fetch through a firewall? Try setting the environment 40variable FTP_PASSIVE_MODE to yes, and see fetch(3) for more details. 41% 42If other operating systems have damaged your Master Boot Record, you can 43reinstall it either with /usr/sbin/sysinstall or with boot0cfg(8). See 44"man boot0cfg" for details. 45% 46If you accidentally end up inside vi, you can quit it by pressing Escape, colon 47(:), q (q), bang (!) and pressing return. 48% 49If you are in the C shell and have just installed a new program, you won't 50be able to run it unless you first type "rehash". 51 -- Dru <genesis@istar.ca> 52% 53If you do not want to get beeps in X11 (X Windows), you can turn them off with 54 55 xset b off 56% 57If you have a CD-ROM drive in your machine, you can make the CD-ROM that is 58presently inserted available by typing 'mount /cdrom' as root. The CD-ROM 59will be available under /cdrom/. Remember to do 'umount /cdrom' before 60removing the CD-ROM (it will usually not be possible to remove the CD-ROM 61without doing this.) 62 63Note: This tip may not work in all configurations. 64% 65If you need a reminder to leave your terminal, type "leave +hhmm" where 66"hhmm" represents in how many hours and minutes you need to leave. 67 -- Dru <genesis@istar.ca> 68% 69If you need to ask a question on the FreeBSD-questions mailing list then 70 71 http://www.FreeBSD.org/doc/en_US.ISO8859-1/articles/\ 72 freebsd-questions/index.html 73 74contains lots of useful advice to help you get the best results. 75% 76If you write part of a filename in tcsh, 77pressing TAB will show you the available choices when there 78is more than one, or complete the filename if there's only one match. 79% 80If you `set watch = (0 any any)' in tcsh, you will be notified when 81someone logs in or out of your system. 82% 83If you use the C shell, add the following line to the .cshrc file in your 84home directory to prevent core files from being written to disk: 85 86 limit coredumpsize 0 87 -- Dru <genesis@istar.ca> 88% 89If you want df(1) and other commands to display disk sizes in 90kilobytes instead of 512-byte blocks, set BLOCKSIZE in your 91environment to 'K'. You can also use 'M' for Megabytes or 'G' for 92Gigabytes. If you want df(1) to automatically select the best size 93then use 'df -h'. 94% 95If you want to play CDs with FreeBSD, a utility for this is already included. 96Type 'cdcontrol' then 'help' to learn more. (You may need to set the CDROM 97environment variable in order to make cdcontrol want to start.) 98% 99If you want to quickly check for duplicate package/port installations, 100try the following pkg_info command. 101 102 pkg_info | sort | sed -e 's/-[0-9].*$//' | \ 103 uniq -c | grep -v '^[[:space:]]*1' 104% 105If you'd like to keep track of applications in the FreeBSD ports tree, take a 106look at FreshPorts; 107 108 http://www.freshports.org/ 109% 110In order to make fetch (the FreeBSD downloading tool) ask for 111username/password when it encounters a password-protected web page, you can set 112the environment variable HTTP_AUTH to 'basic:*'. 113% 114In order to search for a string in some files, use 'grep' like this: 115 116 grep "string" filename1 [filename2 filename3 ...] 117 118This will print out the lines in the files that contain the string. grep can 119also do a lot more advanced searches - type 'man grep' for details. 120% 121In order to support national characters for European languages in tools like 122less without creating other nationalisation aspects, set the environment 123variable LC_ALL to 'en_US.ISO8859-1'. 124% 125"man firewall" will give advice for building a FreeBSD firewall 126 -- David Scheidt <dscheidt@tumbolia.com> 127% 128"man hier" will explain the way FreeBSD filesystems are normally laid out. 129 -- David Scheidt <dscheidt@tumbolia.com> 130% 131Man pages are divided into section depending on topic. There are 9 different 132sections numbered from 1 (General Commands) to 9 (Kernel Developer's Manual). 133You can get an introduction to each topic by typing 134 135 man <number> intro 136 137In other words, to get the intro to general commands, type 138 139 man 1 intro 140% 141"man ports" gives many useful hints about installing FreeBSD ports. 142% 143"man security" gives very good advice on how to tune the security of your 144FreeBSD system. 145% 146"man tuning" gives some tips how to tune performance of your FreeBSD system. 147 -- David Scheidt <dscheidt@tumbolia.com> 148% 149Need to do a search in a manpage or in a file you've sent to a pager? Use 150"/search_word". To repeat the same search, type "n" for next. 151 -- Dru <genesis@istar.ca> 152% 153Need to find the location of a program? Use "locate program_name". 154 -- Dru <genesis@istar.ca> 155% 156Need to leave your terminal for a few minutes and don't want to logout? 157Use "lock -p". When you return, use your password as the key to unlock the 158terminal. 159 -- Dru <genesis@istar.ca> 160% 161Need to print a manpage? Use 162 163 man name_of_manpage | col -bx | lpr 164 -- Dru <genesis@istar.ca> 165% 166Need to quickly empty a file? Use ": > filename". 167 -- Dru <genesis@istar.ca> 168% 169Need to quickly return to your home directory? Type "cd". 170 -- Dru <genesis@istar.ca> 171% 172Need to remove all those ^M characters from a DOS file? Try 173 174 tr -d \\r < dosfile > newfile 175 -- Originally by Dru <genesis@istar.ca> 176% 177Need to see the calendar for this month? Simply type "cal". To see the 178whole year, type "cal -y". 179 -- Dru <genesis@istar.ca> 180% 181Need to see which daemons are listening for connection requests? Use 182"sockstat -4l" for IPv4, and "sockstat -l" for IPv4 and IPv6. 183 -- Dru <genesis@istar.ca> 184% 185Need to see your routing table? Type "netstat -rn". The entry with the G 186flag is your gateway. 187 -- Dru <genesis@istar.ca> 188% 189Nice bash prompt: PS1='(\[$(tput md)\]\t <\w>\[$(tput me)\]) $(echo $?) \$ ' 190 -- Mathieu <mathieu@hal.interactionvirtuelle.com> 191% 192Over quota? "du -s * | sort -n " will give you a sorted list of your 193directory sizes. 194 -- David Scheidt <dscheidt@tumbolia.com> 195% 196nc(1) (or netcat) is useful not only for redirecting input/output to 197TCP or UDP connections, but also for proxying them with inetd(8). 198% 199sh (the default Bourne shell in FreeBSD) supports command-line editing. Just 200``set -o emacs'' or ``set -o vi'' to enable it. 201% 202Simple tcsh prompt: set prompt = '%# ' 203% 204The default editor in FreeBSD is vi, which is efficient to use when you have 205learned it, but somewhat user-unfriendly. To use ee (an easier but less 206powerful editor) instead, set the environment variable EDITOR to /usr/bin/ee 207% 208Time to change your password? Type "passwd" and follow the prompts. 209 -- Dru <genesis@istar.ca> 210% 211To change an environment variable in /bin/sh use: 212 213 $ VARIABLE="value" 214 $ export VARIABLE 215% 216To change an environment variable in tcsh you use: setenv NAME "value" 217where NAME is the name of the variable and "value" its new value. 218% 219To clear the screen, use "clear". To re-display your screen buffer, press 220the scroll lock key and use your page up button. When you're finished, 221press the scroll lock key again to get your prompt back. 222 -- Dru <genesis@istar.ca> 223% 224To determine whether a file is a text file, executable, or some other type 225of file, use 226 227 file filename 228 -- Dru <genesis@istar.ca> 229% 230To do a fast search for a file, try 231 232 locate filename 233 234locate uses a database that is updated every Saturday (assuming your computer 235is running FreeBSD at the time) to quickly find files based on name only. 236% 237To erase a line you've written at the command prompt, use "Ctrl-U". 238 -- Dru <genesis@istar.ca> 239% 240To find out the hostname associated with an IP address, use 241 242 dig -x IP_address 243 -- Dru <genesis@istar.ca> 244% 245To obtain a neat PostScript rendering of a manual page, use ``-t'' switch 246of the man(1) utility: ``man -t <topic>''. For example: 247 248 man -t grep > grep.ps # Save the PostScript version to a file 249or 250 man -t printf | lp # Send the PostScript directly to printer 251% 252To quickly create an empty file, use "touch filename". 253 -- Dru <genesis@istar.ca> 254% 255To read a compressed file without having to first uncompress it, use 256"zcat" or "zless" to view it. 257 -- Dru <genesis@istar.ca> 258% 259To repeat the last command in the C shell, type "!!". 260 -- Dru <genesis@istar.ca> 261% 262To save disk space in your home directory, compress files you rarely 263use with "gzip filename". 264 -- Dru <genesis@istar.ca> 265% 266To search for files that match a particular name, use find(1); for example 267 268 find / -name "*GENERIC*" -ls 269 270will search '/', and all subdirectories, for files with 'GENERIC' in the name. 271 -- Stephen Hilton <nospam@hiltonbsd.com> 272% 273To see all of the directories on your FreeBSD system, type 274 275 ls -R / | less 276 -- Dru <genesis@istar.ca> 277% 278To see how long it takes a command to run, type the word "time" before the 279command name. 280 -- Dru <genesis@istar.ca> 281% 282To see how much disk space is left on your partitions, use 283 284 df -h 285 -- Dru <genesis@istar.ca> 286% 287To see the 10 largest files on a directory or partition, use 288 289 du /partition_or_directory_name | sort -rn | head 290 -- Dru <genesis@istar.ca> 291% 292To see the IP addresses currently set on your active interfaces, type 293"ifconfig -u". 294 -- Dru <genesis@istar.ca> 295% 296To see the last 10 lines of a long file, use "tail filename". To see the 297first 10 lines, use "head filename". 298 -- Dru <genesis@istar.ca> 299% 300To see the last time that you logged in, use lastlogin(8). 301 -- Dru <genesis@istar.ca> 302% 303To see the MAC addresses of the NICs on your system, type 304 305 ifconfig -a 306 -- Dru <genesis@istar.ca> 307% 308To see the output from when your computer started, run dmesg(8). If it has 309been replaced with other messages, look at /var/run/dmesg.boot. 310 -- Francisco Reyes <lists@natserv.com> 311% 312Want colour in your directory listings? Use "ls -G". "ls -F" is also useful, 313and they can be combined as "ls -FG". 314% 315Want to find a specific port, just type the following under /usr/ports 316or one its subdirectories: 317 318 "make search name=<port-name>" 319 or 320 "make search key=<keyword>" 321% 322Want to know how many words, lines, or bytes are contained in a file? Type 323"wc filename". 324 -- Dru <genesis@istar.ca> 325% 326Want to see how much virtual memory you're using? Just type "swapinfo" to 327be shown information about the usage of your swap partitions. 328% 329Want to strip UTF-8 BOM(Byte Order Mark) from given files? 330 331 sed -e '1s/^\xef\xbb\xbf//' < bomfile > newfile 332% 333Want to use sed(1) to edit a file in place? Well, to replace every 'e' with 334an 'o', in a file named 'foo', you can do: 335 336 sed -i.bak s/e/o/g foo 337 338And you'll get a backup of the original in a file named 'foo.bak', but if you 339want no backup: 340 341 sed -i '' s/e/o/g foo 342% 343When you've made modifications to a file in vi(1) and then find that 344you can't write it, type ``<ESC>!rm -f %'' then ``:w!'' to force the 345write 346 347This won't work if you don't have write permissions to the directory 348and probably won't be suitable if you're editing through a symbolic link. 349% 350You can adjust the volume of various parts of the sound system in your 351computer by typing 'mixer <type> <volume>'. To get a list of what you can 352adjust, just type 'mixer'. 353% 354You can automatically download and install binary packages by doing 355 356 pkg_add -r <URL> 357 358where you replace <URL> with the URL to the package. This will also 359automatically install the packages the package you download is dependent on 360(ie, the packages it needs in order to work.) 361% 362You can change the video mode on all consoles by adding something like 363the following to /etc/rc.conf: 364 365 allscreens="80x30" 366 367You can use "vidcontrol -i mode | grep T" for a list of supported text 368modes. 369 -- Konstantinos Konstantinidis <kkonstan@duth.gr> 370% 371You can disable tcsh's terminal beep if you `set nobeep'. 372% 373You can get a good generic server install by using the 374instant-server port/package. If you have ports installed, you can 375install it by doing 376 377 # cd /usr/ports/misc/instant-server 378 # make install && make clean 379 380as root. This will install a collection of packages that is appropriate for 381running a "generic" server. 382% 383You can install extra packages for FreeBSD by using the ports system. 384If you have installed it, you can download, compile, and install software by 385just typing 386 387 # cd /usr/ports/<category>/<portname> 388 # make install && make clean 389 390as root. The ports infrastructure will download the software, change it so 391it works on FreeBSD, compile it, install it, register the installation so it 392will be possible to automatically uninstall it, and clean out the temporary 393working space it used. You can remove an installed port you decide you do not 394want after all by typing 395 396 # cd /usr/ports/<category>/<portname> 397 # make deinstall 398 399as root. 400% 401You can look through a file in a nice text-based interface by typing 402 403 less filename 404% 405You can make a log of your terminal session with script(1). 406% 407You can often get answers to your questions about FreeBSD by searching in the 408FreeBSD mailing list archives at 409 410 http://www.FreeBSD.org/search/search.html 411% 412You can open up a new split-screen window in (n)vi with :N or :E and then 413use ^w to switch between the two. 414% 415You can permanently set environment variables for your shell by putting them 416in a startup file for the shell. The name of the startup file varies 417depending on the shell - csh and tcsh uses .login, bash, sh, ksh and zsh use 418.profile. When using bash, sh, ksh or zsh, don't forget to export the 419variable. 420% 421You can press Ctrl-D to quickly exit from a shell, or logout from a 422login shell. 423 -- Konstantinos Konstantinidis <kkonstan@duth.gr> 424% 425You can press up-arrow or down-arrow to walk through a list of 426previous commands in tcsh. 427% 428You can search for documentation on a keyword by typing 429 430 apropos keyword 431% 432You can `set autologout = 30' to have tcsh log you off automatically 433if you leave the shell idle for more than 30 minutes. 434% 435You can use aliases to decrease the amount of typing you need to do to get 436commands you commonly use. Examples of fairly popular aliases include (in 437Bourne shell style, as in /bin/sh, bash, ksh, and zsh): 438 439 alias lf="ls -FA" 440 alias ll="ls -lA" 441 alias su="su -m" 442 443In csh or tcsh, these would be 444 445 alias lf ls -FA 446 alias ll ls -lA 447 alias su su -m 448 449To remove an alias, you can usually use 'unalias aliasname'. To list all 450aliases, you can usually type just 'alias'. 451% 452You can use /etc/make.conf to control the options used to compile software 453on this system. Example entries are in 454/usr/share/examples/etc/make.conf. 455% 456You can use "pkg_info" to see a list of packages you have installed. 457 -- Konstantinos Konstantinidis <kkonstan@duth.gr> 458% 459You can use the 'fetch' command to retrieve files over ftp or http. 460 461 fetch http://www.FreeBSD.org/index.html 462 463will download the front page of the FreeBSD web site. 464% 465You can use "whereis" to search standard binary, manual page and source 466directories for the specified programs. This can be particularly handy 467when you are trying to find where in the ports tree an application is. 468 469Try "whereis firefox" and "whereis whereis". 470 -- Konstantinos Konstantinidis <kkonstan@duth.gr> 471% 472Want to run the same command again? 473In tcsh you can type "!!" 474% 475Want to go the directory you were just in? 476Type "cd -" 477% 478