freebsd-tips revision 202115
1This fortune brought to you by: 2$FreeBSD: head/games/fortune/datfiles/freebsd-tips 202115 2010-01-11 21:17:49Z gavin $ 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 `set filec' (file completion) in tcsh and write a part of the 77filename, pressing 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% 125In tcsh, you can `set autolist' to have the shell automatically show 126all the possible matches when doing filename/directory expansion. 127% 128"man firewall" will give advice for building a FreeBSD firewall 129 -- David Scheidt <dscheidt@tumbolia.com> 130% 131"man hier" will explain the way FreeBSD filesystems are normally laid out. 132 -- David Scheidt <dscheidt@tumbolia.com> 133% 134Man pages are divided into section depending on topic. There are 9 different 135sections numbered from 1 (General Commands) to 9 (Kernel Developer's Manual). 136You can get an introduction to each topic by typing 137 138 man <number> intro 139 140In other words, to get the intro to general commands, type 141 142 man 1 intro 143% 144"man ports" gives many useful hints about installing FreeBSD ports. 145% 146"man security" gives very good advice on how to tune the security of your 147FreeBSD system. 148% 149"man tuning" gives some tips how to tune performance of your FreeBSD system. 150 -- David Scheidt <dscheidt@tumbolia.com> 151% 152Need to do a search in a manpage or in a file you've sent to a pager? Use 153"/search_word". To repeat the same search, type "n" for next. 154 -- Dru <genesis@istar.ca> 155% 156Need to find the location of a program? Use "locate program_name". 157 -- Dru <genesis@istar.ca> 158% 159Need to leave your terminal for a few minutes and don't want to logout? 160Use "lock -p". When you return, use your password as the key to unlock the 161terminal. 162 -- Dru <genesis@istar.ca> 163% 164Need to print a manpage? Use 165 166 man name_of_manpage | col -bx | lpr 167 -- Dru <genesis@istar.ca> 168% 169Need to quickly empty a file? Use ": > filename". 170 -- Dru <genesis@istar.ca> 171% 172Need to quickly return to your home directory? Type "cd". 173 -- Dru <genesis@istar.ca> 174% 175Need to remove all those ^M characters from a DOS file? Try 176 177 tr -d \\r < dosfile > newfile 178 -- Originally by Dru <genesis@istar.ca> 179% 180Need to see the calendar for this month? Simply type "cal". To see the 181whole year, type "cal -y". 182 -- Dru <genesis@istar.ca> 183% 184Need to see which daemons are listening for connection requests? Use 185"sockstat -4l" for IPv4, and "sockstat -l" for IPv4 and IPv6. 186 -- Dru <genesis@istar.ca> 187% 188Need to see your routing table? Type "netstat -rn". The entry with the G 189flag is your gateway. 190 -- Dru <genesis@istar.ca> 191% 192Nice bash prompt: PS1='(\[$(tput md)\]\t <\w>\[$(tput me)\]) $(echo $?) \$ ' 193 -- Mathieu <mathieu@hal.interactionvirtuelle.com> 194% 195Nice tcsh prompts: 196 set prompt = '[%B%m%b] %B%~%b%# ' 197 set prompt = '%m %# ' 198 set prompt = '%n@%m%# ' 199 set prompt = '%n@%m:%/%# ' 200 set prompt = '%n@%m:%~%# ' 201% 202Over quota? "du -s * | sort -n " will give you a sorted list of your 203directory sizes. 204 -- David Scheidt <dscheidt@tumbolia.com> 205% 206nc(1) (or netcat) is useful not only for redirecting input/output to 207TCP or UDP connections, but also for proxying them with inetd(8). 208% 209sh (the default Bourne shell in FreeBSD) supports command-line editing. Just 210``set -o emacs'' or ``set -o vi'' to enable it. 211% 212Simple tcsh prompt: set prompt = '%# ' 213% 214The default editor in FreeBSD is vi, which is efficient to use when you have 215learned it, but somewhat user-unfriendly. To use ee (an easier but less 216powerful editor) instead, set the environment variable EDITOR to /usr/bin/ee 217% 218Time to change your password? Type "passwd" and follow the prompts. 219 -- Dru <genesis@istar.ca> 220% 221To change an environment variable in /bin/sh use: 222 223 $ VARIABLE="value" 224 $ export VARIABLE 225% 226To change an environment variable in tcsh you use: setenv NAME "value" 227where NAME is the name of the variable and "value" its new value. 228% 229To clear the screen, use "clear". To re-display your screen buffer, press 230the scroll lock key and use your page up button. When you're finished, 231press the scroll lock key again to get your prompt back. 232 -- Dru <genesis@istar.ca> 233% 234To determine whether a file is a text file, executable, or some other type 235of file, use 236 237 file filename 238 -- Dru <genesis@istar.ca> 239% 240To do a fast search for a file, try 241 242 locate filename 243 244locate uses a database that is updated every Saturday (assuming your computer 245is running FreeBSD at the time) to quickly find files based on name only. 246% 247To erase a line you've written at the command prompt, use "Ctrl-U". 248 -- Dru <genesis@istar.ca> 249% 250To find out the hostname associated with an IP address, use 251 252 dig -x IP_address 253 -- Dru <genesis@istar.ca> 254% 255To obtain a neat PostScript rendering of a manual page, use ``-t'' switch 256of the man(1) utility: ``man -t <topic>''. For example: 257 258 man -t grep > grep.ps # Save the PostScript version to a file 259or 260 man -t printf | lp # Send the PostScript directly to printer 261% 262To quickly create an empty file, use "touch filename". 263 -- Dru <genesis@istar.ca> 264% 265To read a compressed file without having to first uncompress it, use 266"zcat" or "zmore" to view it. 267 -- Dru <genesis@istar.ca> 268% 269To repeat the last command in the C shell, type "!!". 270 -- Dru <genesis@istar.ca> 271% 272To save disk space in your home directory, compress files you rarely 273use with "gzip filename". 274 -- Dru <genesis@istar.ca> 275% 276To search for files that match a particular name, use find(1); for example 277 278 find / -name "*GENERIC*" -ls 279 280will search '/', and all subdirectories, for files with 'GENERIC' in the name. 281 -- Stephen Hilton <nospam@hiltonbsd.com> 282% 283To see all of the directories on your FreeBSD system, type 284 285 ls -R / | more 286 -- Dru <genesis@istar.ca> 287% 288To see how long it takes a command to run, type the word "time" before the 289command name. 290 -- Dru <genesis@istar.ca> 291% 292To see how much disk space is left on your partitions, use 293 294 df -h 295 -- Dru <genesis@istar.ca> 296% 297To see the 10 largest files on a directory or partition, use 298 299 du /partition_or_directory_name | sort -rn | head 300 -- Dru <genesis@istar.ca> 301% 302To see the IP addresses currently set on your active interfaces, type 303"ifconfig -u". 304 -- Dru <genesis@istar.ca> 305% 306To see the last 10 lines of a long file, use "tail filename". To see the 307first 10 lines, use "head filename". 308 -- Dru <genesis@istar.ca> 309% 310To see the last time that you logged in, use lastlogin(8). 311 -- Dru <genesis@istar.ca> 312% 313To see the MAC addresses of the NICs on your system, type 314 315 ifconfig -a 316 -- Dru <genesis@istar.ca> 317% 318To see the output from when your computer started, run dmesg(8). If it has 319been replaced with other messages, look at /var/run/dmesg.boot. 320 -- Francisco Reyes <lists@natserv.com> 321% 322Want colour in your directory listings? Use "ls -G". "ls -F" is also useful, 323and they can be combined as "ls -FG". 324% 325Want to find a specific port, just type the following under /usr/ports, 326or one its subdirectories: 327 328 "make search name=<port-name>" 329 or 330 "make search key=<keyword>" 331% 332Want to know how many words, lines, or bytes are contained in a file? Type 333"wc filename". 334 -- Dru <genesis@istar.ca> 335% 336Want to see how much virtual memory you're using? Just type "swapinfo" to 337be shown information about the usage of your swap partitions. 338% 339Want to strip UTF-8 BOM(Byte Order Mark) from given files? 340 341 sed -e '1s/^\xef\xbb\xbf//' < bomfile > newfile 342% 343Want to use sed(1) to edit a file in place? Well, to replace every 'e' with 344an 'o', in a file named 'foo', you can do: 345 346 sed -i.bak s/e/o/g foo 347 348And you'll get a backup of the original in a file named 'foo.bak', but if you 349want no backup: 350 351 sed -i '' s/e/o/g foo 352% 353When you've made modifications to a file in vi(1) and then find that 354you can't write it, type ``<ESC>!rm -f %'' then ``:w!'' to force the 355write 356 357This won't work if you don't have write permissions to the directory 358and probably won't be suitable if you're editing through a symbolic link. 359% 360You can adjust the volume of various parts of the sound system in your 361computer by typing 'mixer <type> <volume>'. To get a list of what you can 362adjust, just type 'mixer'. 363% 364You can automatically download and install binary packages by doing 365 366 pkg_add -r <URL> 367 368where you replace <URL> with the URL to the package. This will also 369automatically install the packages the package you download is dependent on 370(ie, the packages it needs in order to work.) 371% 372You can change the video mode on all consoles by adding something like 373the following to /etc/rc.conf: 374 375 allscreens="80x30" 376 377You can use "vidcontrol -i mode | grep T" for a list of supported text 378modes. 379 -- Konstantinos Konstantinidis <kkonstan@duth.gr> 380% 381You can disable tcsh's terminal beep if you `set nobeep'. 382% 383You can get a good generic server install by using the 384instant-server port/package. If you have ports installed, you can 385install it by doing 386 387 # cd /usr/ports/misc/instant-server 388 # make install && make clean 389 390as root. This will install a collection of packages that is appropriate for 391running a "generic" server. 392% 393You can install extra packages for FreeBSD by using the ports system. 394If you have installed it, you can download, compile, and install software by 395just typing 396 397 # cd /usr/ports/<category>/<portname> 398 # make install && make clean 399 400as root. The ports infrastructure will download the software, change it so 401it works on FreeBSD, compile it, install it, register the installation so it 402will be possible to automatically uninstall it, and clean out the temporary 403working space it used. You can remove an installed port you decide you do not 404want after all by typing 405 406 # cd /usr/ports/<category>/<portname> 407 # make deinstall 408 409as root. 410% 411You can look through a file in a nice text-based interface by typing 412 413 less filename 414% 415You can make a log of your terminal session with script(1). 416% 417You can often get answers to your questions about FreeBSD by searching in the 418FreeBSD mailing list archives at 419 420 http://www.FreeBSD.org/search/search.html 421% 422You can open up a new split-screen window in (n)vi with :N or :E and then 423use ^w to switch between the two. 424% 425You can permanently set environment variables for your shell by putting them 426in a startup file for the shell. The name of the startup file varies 427depending on the shell - csh and tcsh uses .login, bash, sh, ksh and zsh use 428.profile. When using bash, sh, ksh or zsh, don't forget to export the 429variable. 430% 431You can press Ctrl-D to quickly exit from a shell, or logout from a 432login shell. 433 -- Konstantinos Konstantinidis <kkonstan@duth.gr> 434% 435You can press up-arrow or down-arrow to walk through a list of 436previous commands in tcsh. 437% 438You can search for documentation on a keyword by typing 439 440 apropos keyword 441% 442You can `set autologout = 30' to have tcsh log you off automatically 443if you leave the shell idle for more than 30 minutes. 444% 445You can use aliases to decrease the amount of typing you need to do to get 446commands you commonly use. Examples of fairly popular aliases include (in 447Bourne shell style, as in /bin/sh, bash, ksh, and zsh): 448 449 alias lf="ls -FA" 450 alias ll="ls -lA" 451 alias su="su -m" 452 453In csh or tcsh, these would be 454 455 alias lf ls -FA 456 alias ll ls -lA 457 alias su su -m 458 459To remove an alias, you can usually use 'unalias aliasname'. To list all 460aliases, you can usually type just 'alias'. 461% 462You can use /etc/make.conf to control the options used to compile software 463on this system. Example entries are in 464/usr/share/examples/etc/make.conf. 465% 466You can use "pkg_info" to see a list of packages you have installed. 467 -- Konstantinos Konstantinidis <kkonstan@duth.gr> 468% 469You can use the 'fetch' command to retrieve files over ftp or http. 470 471 fetch http://www.FreeBSD.org/index.html 472 473will download the front page of the FreeBSD web site. 474% 475You can use "whereis" to search standard binary, manual page and source 476directories for the specified programs. This can be particularly handy 477when you are trying to find where in the ports tree an application is. 478 479Try "whereis netscape" and "whereis whereis". 480 -- Konstantinos Konstantinidis <kkonstan@duth.gr> 481% 482