Commands by eightmillion (20)

  • This command outputs a table of sighting opportunities for the International Space Station. Find the URL for your city here: http://spaceflight.nasa.gov/realdata/sightings/ Show Sample Output


    5
    links -dump "http://spaceflight.nasa.gov/realdata/sightings/cities/view.cgi?country=United_States&region=Wisconsin&city=Portage" | sed -n '/--/,/--/p'
    eightmillion · 2011-05-03 12:15:56 2
  • This uses Perl's rename utility (you may have to call it as prename on your box) and won't choke on spaces or other characters in filenames. It will also zero pad a number even in filenames like "vacation-4.jpg".


    12
    rename 's/\d+/sprintf("%04d",$&)/e' *.jpg
    eightmillion · 2011-05-01 20:50:36 1
  • This command finds and prints all the symbolic and hard links to a file. Note that the file argument itself be a link and it will find the original file as well. You can also do this with the inode number for a file or directory by first using stat or ls or some other tool to get the number like so: stat -Lc %i file or ls -Hid file And then using: find -L / -inum INODE_NUMBER -exec ls -ld {} +


    17
    find -L / -samefile /path/to/file -exec ls -ld {} +
    eightmillion · 2011-04-27 06:14:15 3
  • This function is used to set environmental variables from a list of alternatives depending on what's installed on the system. It returns the first program found in the list. Example usage: export BROWSER=$(find_alternatives chromium-browser google-chrome opera firefox firefox-bin iceweasel konqueror w3m lynx) . export EDITOR=$(find_alternatives vim nano pico emacs kate) . export PAGER=$(find_alternatives vimpager less most more pg)


    -1
    find_alternatives(){ for i;do which "$i" >/dev/null && { echo "$i"; return 0;};done;return 1;}
    eightmillion · 2011-01-06 19:53:46 0
  • Ruby version. Also, a perl version: perl -e 'printf("%.2x.",rand(255))for(1..5);printf("%.2x\n",rand(255))'


    3
    ruby -e 'puts (1..6).map{"%0.2X"%rand(256)}.join(":")'
    eightmillion · 2010-12-08 10:01:31 1
  • This command turns a multi-line file into a single line joined with <SOMETEXT>. To skip blank lines, use: perl -pe '(eof()||s/^\s*$//)||s/\n/<SOMETEXT>/g' file.txt Show Sample Output


    3
    perl -pe 'eof()||s/\n/<SOMETEXT>/g' file.txt
    eightmillion · 2010-12-02 01:19:27 2
  • I took matthewbauer's cool one-liner and rewrote it as a shell function that returns all the suggestions or outputs "OK" if it doesn't find anything wrong. It should work on ksh, zsh, and bash. Users that don't have tee can leave that part off like this: spellcheck(){ typeset y=$@;curl -sd "<spellrequest><text>$y</text></spellrequest>" https://google.com/tbproxy/spell|sed -n '/s="[1-9]"/{s/<[^>]*>/ /g;s/\t/ /g;s/ *\(.*\)/Suggestions: \1\n/g;p}';} Show Sample Output


    6
    spellcheck(){ typeset y=$@;curl -sd "<spellrequest><text>$y</text></spellrequest>" https://www.google.com/tbproxy/spell|sed -n '/s="[0-9]"/{s/<[^>]*>/ /g;s/\t/ /g;s/ *\(.*\)/Suggestions: \1\n/g;p}'|tee >(grep -Eq '.*'||echo -e "OK");}
    eightmillion · 2010-02-17 08:20:48 2
  • I use this alias in my bashrc. The --vi-keys option makes info use vi-like and less-like key bindings.


    4
    alias info='info --vi-keys'
    eightmillion · 2010-02-16 16:35:17 0
  • Converts reserved characters in a URI to their percent encoded counterparts. Alternate python version: echo "$url" | python -c 'import sys,urllib;print urllib.quote(sys.stdin.read().strip())' Show Sample Output


    7
    echo "$url" | perl -MURI::Escape -ne 'chomp;print uri_escape($_),"\n"'
    eightmillion · 2010-02-13 00:44:48 0
  • This shell function grabs the weather forecast for the next 24 to 48 hours from weatherunderground.com. Replace <YOURZIPORLOCATION> with your zip code or your "city, state" or "city, country", then calling the function without any arguments returns the weather for that location. Calling the function with a zip code or place name as an argument returns the weather for that location instead of your default. To add a bit of color formatting to the output, use the following instead: weather(){ curl -s "http://api.wunderground.com/auto/wui/geo/ForecastXML/index.xml?query=${@:-<YOURZIPORLOCATION>}"|perl -ne '/<title>([^<]+)/&&printf "\x1B[0;34m%s\x1B[0m: ",$1;/<fcttext>([^<]+)/&&print $1,"\n"';} Requires: perl, curl Show Sample Output


    7
    weather(){ curl -s "http://api.wunderground.com/auto/wui/geo/ForecastXML/index.xml?query=${@:-<YOURZIPORLOCATION>}"|perl -ne '/<title>([^<]+)/&&printf "%s: ",$1;/<fcttext>([^<]+)/&&print $1,"\n"';}
    eightmillion · 2010-02-10 01:23:39 5
  • This function takes a word or a phrase as arguments and then fetches definitions using Google's "define" syntax. The "nl" and perl portion isn't strictly necessary. It just makes the output a bit more readable, but this also works: define(){ local y="$@";curl -sA"Opera" "http://www.google.com/search?q=define:${y// /+}"|grep -Po '(?<=<li>)[^<]+';} If your version of grep doesn't have perl compatible regex support, then you can use this version: define(){ local y="$@";curl -sA"Opera" "http://www.google.com/search?q=define:${y// /+}"|grep -Eo '<li>[^<]+'|sed 's/<li>//g'|nl|perl -MHTML::Entities -pe 'decode_entities($_)' 2>/dev/null;} Show Sample Output


    18
    define(){ local y="$@";curl -sA"Opera" "http://www.google.com/search?q=define:${y// /+}"|grep -Po '(?<=<li>)[^<]+'|nl|perl -MHTML::Entities -pe 'decode_entities($_)' 2>/dev/null;}
    eightmillion · 2010-01-29 05:01:11 4
  • This is a command that I find myself using all the time. It works like regular grep, but returns the paragraph containing the search pattern instead of just the line. It operates on files or standard input. grepp <PATTERN> <FILE> or <SOMECOMMAND> | grepp <PATTERN> Show Sample Output


    13
    grepp() { [ $# -eq 1 ] && perl -00ne "print if /$1/i" || perl -00ne "print if /$1/i" < "$2";}
    eightmillion · 2010-01-12 04:30:15 5
  • This command, taken from play's manual page, plays a synthesized guitar tone for each of the strings on a standard tuned guitar. The command "play" is a part of the package "sox".


    18
    for n in E2 A2 D3 G3 B3 E4;do play -n synth 4 pluck $n repeat 2;done
    eightmillion · 2009-12-13 06:57:26 5
  • This function displays the latest comic from xkcd.com. One of the best things about xkcd is the title text when you hover over the comic, so this function also displays that after you close the comic. To get a random xkcd comic, I also use the following: xkcdrandom(){ wget -qO- dynamic.xkcd.com/comic/random|tee >(feh $(grep -Po '(?<=")http://imgs[^/]+/comics/[^"]+\.\w{3}'))|grep -Po '(?<=(\w{3})" title=").*(?=" alt)';}


    24
    xkcd(){ wget -qO- http://xkcd.com/|tee >(feh $(grep -Po '(?<=")http://imgs[^/]+/comics/[^"]+\.\w{3}'))|grep -Po '(?<=(\w{3})" title=").*(?=" alt)';}
    eightmillion · 2009-11-27 09:11:47 6
  • This uses mpg123 to convert the files to wav before burning, but you can use mplayer or mencoder or ffmpeg or lame with the --decode option, or whatever you like.


    3
    alias burnaudiocd='mkdir ./temp && for i in *.[Mm][Pp]3;do mpg123 -w "./temp/${i%%.*}.wav" "$i";done;cdrecord -pad ./temp/* && rm -r ./temp'
    eightmillion · 2009-11-21 19:57:18 0
  • Substitute feh for the image viewer of your choice. display (part of imagemagick) seems to be a popular choice.


    3
    apod(){ local x=http://antwrp.gsfc.nasa.gov/apod/;feh $x$(curl -s ${x}astropix.html|grep -Pom1 'image/\d+/.*\.\w+');}
    eightmillion · 2009-11-18 12:06:03 1
  • This bash function uses albumart.org to find the cover for an album. It returns an amazon.com url to the image. Usage: albumart [artist] [album] These arguments can be reversed and if the album name is distinct enough, it may be possible to omit the artist. The command can be extended with wget to automatically download the matching image like this: albumart(){ local x y="$@";x=$(awk '/View larger image/{gsub(/^.*largeImagePopup\(.|., .*$/,"");print;exit}' <(curl -s 'http://www.albumart.org/index.php?srchkey='${y// /+}'&itempage=1&newsearch=1&searchindex=Music'));[ -z "$x" ]&&echo "Not found."||wget "$x" -O "${y}.${x##*.}";} Show Sample Output


    7
    albumart(){ local y="$@";awk '/View larger image/{gsub(/^.*largeImagePopup\(.|., .*$/,"");print;exit}' <(curl -s 'http://www.albumart.org/index.php?srchkey='${y// /+}'&itempage=1&newsearch=1&searchindex=Music');}
    eightmillion · 2009-11-15 19:54:16 1
  • This command lets you select from 10 different BBC stations. When one is chosen, it streams it with mplayer. Requires: mplayer with wma support.


    23
    bbcradio() { local s PS3="Select a station: ";select s in 1 1x 2 3 4 5 6 7 "Asian Network an" "Nations & Local lcl";do break;done;s=($s);mplayer -playlist "http://www.bbc.co.uk/radio/listen/live/r"${s[@]: -1}".asx";}
    eightmillion · 2009-11-14 08:17:03 11
  • This function uploads images to http://omploader.org and then prints out the links to the file. Some coloring can also be added to the command with: ompload() { curl -F file1=@"$1" http://omploader.org/upload|awk '/Info:|File:|Thumbnail:|BBCode:/{gsub(/<[^<]*?\/?>/,"");$1=$1;sub(/^/,"\033[0;34m");sub(/:/,"\033[0m:");print}';} Show Sample Output


    8
    ompload() { curl -# -F file1=@"$1" http://ompldr.org/upload|awk '/Info:|File:|Thumbnail:|BBCode:/{gsub(/<[^<]*?\/?>/,"");$1=$1;print}';}
    eightmillion · 2009-11-07 20:56:52 1
  • This is a kind of wrapper around the shell builtin cd that allows a person to quickly go up several directories. Instead of typing: cd ../.. A user can type: cd ... Instead of: cd ../../.. Type: cd .... Add another period and it goes up four levels. Adding more periods will take you up more levels.


    5
    cd() { if [[ "$1" =~ ^\.\.+$ ]];then local a dir;a=${#1};while [ $a -ne 1 ];do dir=${dir}"../";((a--));done;builtin cd $dir;else builtin cd "$@";fi ;}
    eightmillion · 2009-10-29 21:43:51 4

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Function to split a string into an array

a find and replace within text-based files, for batch text replacement, not using perl
Use sed to edit in-place a list of files returned by find.

Prefix every line with a timestamp
Useful to add a timestamp to every line printed to stdout. You can use `-Ins` instead of `-Iseconds` if you want more precision.

Get the header of a website

A snooze button for xmms2 alarm clock
you can also run "xmms2 pause & at now +5min

Find status of all symlinks
The symlinks command can show status of all symbolic links, including which links are dangling, which symlinks point to files on other file systems, which symlinks use ../ more than necessary, which symlinks are messy (e.g. having too many slashes or dots), etc. Other useful things it can do include removing all dangling links (-d) and converting absolute links to relative links (-c). The path given must be an absolute path (which is why I used $(pwd) in the example command).

Limit the transfer rate and size of data over a pipe
This example will close the pipe after transferring 100MB at a speed of 3MB per second.

grep certain file types recursively
-exec works better and faster then using a pipe

ttyS0 - terminal on serial connection
I actually planned to do this for quite a long time, but since I haven't had any suitable client hardware, I procrastinated this. Now, the old laptop I've got from my dad, features an RS-232 port. So, now that I had technically a client, that I could test my RS-232 connection with, I ordered a null modem cable. There is no RS-232 outlet on my desktop computer directly on the mainboard, but theres a connector on the mainbord, where a RS-232 outlet can be attached to. The outlet will then cover up a PCI slot. # Activating RS-232 Ok, once all cables were in place, I tried to access both RS-232 ports by reading from them directly. They're usually ttyS0 or ttyS1, depending what COM-Port it is. From the file /proc/tty/driver/serial, information about the serial setup can be obtained. A setserial -q /dev/ttyS0 might be usefull as well. Usually, the UART Type is 16550A, on a standard PC. Mine wasn't working though. At leas not right from the start, when I tried to read the interface with cat /dev/ttyS0 I got the following error: # cat /dev/ttyS0 cat: /dev/ttyS0: Input/output error Obviously, the driver couldn't activate the hardware. Reason was, it was deactivated in BIOS. After activating RS-232 there, it worked well. As a last action, I added myself to the uucp group, so I have user permission to the serial lines. It is not necessary for the terminal setup, but a good idea to do so, just for future projects, maybe... # Setting up a terminal Once the Serial line is configured and working properly, it's time to let a terminal run on that port. This is what I added to my /etc/inittab : s0:2345:respawn:/sbin/agetty -L 38400 ttyS0 I added it quite on the top of that file, right below the 'si' statement, mingetty cannot be used for serial connections, it cannot be run in a console, too. I tried it for testing purposes, but the cosole - along with your login program - will log you out, as soon as you log in over your serial line. '-L' means this is a local line, with no carrier signal. 38400 is the standard speed of a Linux console, it might be a bit high, I was told, but it works well. I tested that with some higher values as well (115200) and it worked too, I guess it tepends on things like cable length, etc. Last parameter, is the serial tty to listen on. The terminal type can be specified as an additional parameter at the end of the parameter list, vt102, for instance. This is sometimes required, depending on the client. After finishing editing /etc/inittab, an init q will make the system re-read /etc/inittab and apply changes. The agetty should now be listening on ttyS0. #Setting up a client It's time to establish a connection and test the serial line. I use a laptop, that has an RS-232 port, so some preliminary setup is required. I tried minicom as terminal initially, but it turned out, not to be the best client. It initializes the modem, this lasts quite long, and it doesn't convey ANSI colors. So the better option is cu, it's part of the UUCP-Package. Oh, and the serial port of that computer, has to be accessible as well, of course. Once everything was set up, I established the connection: $ cu -l ttyS0 -38400 --nostop Pretty self explanatory, I think. The --nostop option disables XON/XOFF handling. # root access over ttyS0 In order to become root over the serial terminal, the tty needs to be added to /etc/securetty I appended ttyS0 to the end of the file. It is now possible, to gain root access over the serial terminal. The agetty process needs to be restarted to apply changes. # Accessing GRUB over ttyS0 To make bootloader access possible over ttyS0, some changes to /boot/grub/menu.lst need to be done. (GRUB is the bootloader I use, I suppose LiLo has similar capabilities.) Those are the lines, I appended to the top of my menu.lst : serial --unit=0 --speed=38400 --word=8 --parity=no --stop=1 terminal --timeout=3 serial console The serial command initiates the serial terminal option, --unit=0 defines our first serial connector, I my case, it's the only one I have on my machine. I used the standard Linux-Console speed, as well as the "8N1" connection strategy. terminal defines the terminal priorities, first terminal (serial) is the standard one, the last one is the secondary terminal (console). --timeout=3 enables a delay on both consoles, with a prompt for a keystroke. Depending on which terminal, the key is pressed, this terminal, will be used. If no key is pressed after the timeout, the standard console (in my case serial) will be used. # Relaying Kernel output on boot The Kernel accepts multiple console options, of which the last one, is the standard console, and the one that will be used in Single User mode. These are my Kernel options: title Fedora Core (2.6.20-1.2316.fc5) root (hd0,0) kernel /vmlinuz-2.6.20-1.2316.fc5 ro root=/dev/VolGroup00/LogVol00 rhgb quiet vga=795 console=tty0 console=ttyS0,38400 initrd /initrd-2.6.20-1.2316.fc5.img console=tty0 is the standard console, located on the machine, i.e. monitor and keyboard.

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