//A few nice Unix commands.//

====== Shell and simple command line applications ======

===== Erase all in a directory except one file (or so) =====

<code>
for i in `ls -1 | grep -v <filetokeep>`; do rm -rf $i; done
</code>

===== Hexadecimal =====

==== Convert hexdump's output to C hex array ====

More exactly, it'll convert from "AA BB CC" to "0xAA, 0xBB, 0xCC" with each line having 8 bytes.

<code>
hexdump -v -e '8/1 "0x%02x, "' -e '"\n"' <filetodump>
</code>

===== ls =====

Colour directories, binaries (etc) using ls --color=auto.

===== Screenshots =====

Take a screenshot of the entire desktop
<code>
$ xwd -root -out scrdump
</code>

Take a screenshot of a given window: 
<code>
$ xwd -out scrdump
</code>
and point to the window to grab with the mouse.


View a screenshot
<code>
$ xwud -in scrdump 
</code>


===== Tar =====

==== Untar a single file in a big tar file ====

<code>
tar -xvf <thetar.tar> <thefile>
</code>

==== Untar in a given directory ====

<code>
tar -xvf <thetar.tar> -C <thedir>
</code>


====== Development ======


===== Compilation =====

  * to generate a .s: gcc -S -c foo.c
  * to output combined C and assembly: gcc -c -g -Wa,-a,-ad foo.c > foo.lst
  * to assemble a .s: as -o foo.o foo.s. Use -gstabs for debug and -a to print memory listing.
  * to assemble a .o: gcc foo.o -o foo