Commands by ahabman (1)

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Merge PDFs with Ghostscript wrapped in a function
This is an expansion on a previous entry, which I've wrapped in a function and placed in my profile. The "$@" is a positional parameter, much like "$*", but the parameters are passed on intact, without interpretation or expansion; so you can simply call the function like this: mergepdf * This will output a merged PDF of all PDFs in the current directory. Alternatively, you can simply list them like so: mergepdf 00.pdf 01.pdf 02.pdf ... N.B. Passing a wildcard will merge all PDFs in the current directory in name order, e.g. 00.pdf 01.pdf aa.pdf ab.pdf

Create cheap and easy index.html file
If your admin has disabled Apache's directory index feature but you want to have a cheap way to enable it for one folder, this command will just create an index.html file with a link to each file in the directory (including the index.html file, which is not ideal but makes the command much simpler). The HTML isn't even remotely compliant, but it could easily be improved on. Also, the command needs to be run each time a file is added or removed to update the index.html file.

Image to color palette generator
Extract a color palette from a image useful for designers. Example usage: $extract-palette myawesomeimage.jpg 4 Where the first argument is the image you want to extract a palette from. The second argument is the number of colors you want. It may be the case where you want to change the search space. In that case, change the -resize argument to a bigger or smaller result. See the ImageMagick documentation for the -resize argument.

Compute the numeric sum of a file
In the file data.txt there is a single column of numbers. Sed adds a "+" between lines and xargs prepares the output for bc. The "echo 0" is to avoid to have a "+" at the beginning of the line.

video volume boost

Spoof your wireless MAC address on OS X to 00:e2:e3:e4:e5:e6
If you want to check that the spoof worked, type the same command as earlier: $ifconfig en1 | grep ether Now you will see: $ether 00:e2:e3:e4:e5:e6 For the wired ethernet port: $sudo ifconfig en0 ether 00:e2:e3:e4:e5:e6

command line Google I'm Feeling Lucky
opens the Google I'm Feeling Lucky result in lynx, the command line browser

See system users

Print a single route to a destination and its contents exactly as the kernel sees it
Useful to determine the source_ip of outgoing packages to a certain destination

Look up a unicode character by name
[Update! Thanks to a tip from ioggstream, I've fixed both of the bugs mentioned below.] You, yes, 𝙔𝙊𝙐, can be the terror of the Internet! Why use normal, boring bullet points in your text, when you could use a ROTATED HEAVY BLACK HEART BULLET (❥)!? (Which would also be an awesome band name, by the way).  This script makes it easy to find unusual characters from the command line. You can then cut and paste them or, if you're using a GTK application, type Control+Shift+U followed by the code point number (e.g., 2765) and then a SPACE.  USAGE: Put this script in a file (I called mine "ugrep") and make it executable. Run it from the command line like so,  $ ugrep heart  The output will look like this,  ☙ U+2619 REVERSED ROTATED FLORAL HEART BULLET ♡ U+2661 WHITE HEART SUIT ♥ U+2665 BLACK HEART SUIT ❣ U+2763 HEAVY HEART EXCLAMATION MARK ORNAMENT ❤ U+2764 HEAVY BLACK HEART ❥ U+2765 ROTATED HEAVY BLACK HEART BULLET ❦ U+2766 FLORAL HEART ❧ U+2767 ROTATED FLORAL HEART BULLET ⺖ U+2E96 CJK RADICAL HEART ONE ⺗ U+2E97 CJK RADICAL HEART TWO ⼼ U+2F3C KANGXI RADICAL HEART  You can, of course, use regular expressions. For example, if you are looking for the "pi" symbol, you could do this:  $ ugrep '\bpi\b'  REQUIREMENTS: Although this is written in Bash, it assumes you have Perl installed because it greps through the Perl Unicode character name module (/usr/lib/perl5/Unicode/CharName.pm). Note that it would not have made more sense to write this in Perl, since the CharName.pm module doesn't actually include a subroutine for looking up a character based on the description. (Weird.)  BUGS: In order to fit this script in the commandlinefu limits, a couple bugs were added. ① Astral characters beyond the BMP (basic multilingual plane) are not displayed correctly, but see below. ② Perl code from the perl module being grepped is sometimes extraneously matched.  MISFEATURES: Bash's printf cannot, given a Unicode codepoint, print the resulting character to the terminal. GNU's coreutils printf (usually "/usr/bin/printf") can do so, but it is brokenly pedantic about how many hexadecimal digits follow the escape sequence and will actually die with an error if you give the wrong number. This is especially annoying since Unicode code points are usually variable length with implied leading zeros. The CharNames.pm file represents BMP characters as 4 hexits, but astral characters as 5. In the actual version of this script that I use, I've kludged around this misfeature by zero-padding to 8 hexits like so,  $ /usr/bin/printf "\U$(printf "%08x" 0x$hex)"  TIP 1: The author recommends "xsel" for command line cut-and-paste. For example,  $ ugrep biohazard | xsel  TIP 2: In Emacs, instead of running this command in a subshell, you can type Unicode code points directly by pressing Control-Q first, but you'll likely want to change the default input from octal to hexadecimal. (setq read-quoted-char-radix 16).  TIP 3: Of course, if you're using X, and you want to type one of the more common unusual characters, it's easiest of all to do it with your Compose (aka Multi) key. For example, hitting [Compose] <3 types ♥.


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