Logo.

CONTRIBUTING.md

@@ -1,5 +1,5 @@
-#Contributing Guidelines
+#Contributing guidelines
 
 Use the following Markdown style: <https://github.com/cirosantilli/markdown-styleguide> W2.
 
-If automatic assertions can be made for the entire file to be run, put it in a `.sh` file. Otherwise, put it on a `.md` file.
+If automatic assertions can be made for the entire file to be run, put it in a `.sh` file. Otherwise, put it on a `.md` file. 

README.md

@@ -1,4 +1,4 @@
-#Linux Cheat
+# ![logo](logo.jpg) Linux Cheat
 
 Linux information and cheatsheets.
 

etc.md

@@ -0,0 +1,14 @@
+#/etc/issue
+
+Contains the message that is printed before login shells (Ubuntu Ctrl + Alt + 1).
+
+See:
+
+    man issue
+
+<http://unix.stackexchange.com/questions/84280/is-etc-issue-common-file>
+
+Of course, since this is meant to be shown to end users,
+it serves as a broadcast message for CLI only environments,
+and should not be used to identify the distribution even though
+it usually contains the distribution ID by default.

game.md

@@ -50,7 +50,7 @@ List games on Ubuntu:
 
 Review top 10: <http://techtinkering.com/2009/08/11/my-top-10-classic-text-mode-bsd-games/>
 
-###adventure games
+###Adventure games
 
 Computer RPGs.
 
@@ -146,7 +146,7 @@ CLI go.
 
 Conway's game of life simulator
 
-Because the global menu does not work, deactivate it on ubuntu:
+Because the global menu does not work, deactivate it on Ubuntu:
 
     env UBUNTU_MENUPROXY=0 golly
 
@@ -156,7 +156,7 @@ Minesweeper clone
 
     gnomine
 
-##gnotski
+##Gnotski
 
 Knotski clone.
 
@@ -170,53 +170,53 @@ Also known as connect four.
 
 Warning: this games has been solved, so the program might do perfect play =)
 
-#kde
+#KDE
 
 ##kreversi
 
 Reversi for KDE.
 
 #fps
 
-##urban terror
+##Urban Terror
 
 CS like, but mostly capture the flag.
 
 Good inertia, not too fast.
 
 Free but closed source.
 
-##world of padman
+##World of Padman
 
 FPS, very large scenarios, cool weapons.
 
 Too fast for my taste.
 
 #clones
 
-##pingus
+##Pingus
 
-Great lemmings clone.
+Lemmings clone.
 
 Includes map designer.
 
-##hedgewars
+##Hedgewars
 
-Great worms clone, has same feeling. Includes map builder.
+Worms clone, has same feeling. Includes map builder.
 
-##super maryo chronicles
+##Super Maryo Chronicles
 
 Super mario bros clone.
 
 ##Tux Kart
 
 Mario Kart 64 clone.
 
-#strategy
+#Strategy
 
-##battle for wesnoth
+##Battle for Wesnoth
 
-Turn based unit control on 2d hexagonal map.
+Turn based unit control on 2D hexagonal map.
 
 Very addictive and time consuming.
 
@@ -306,7 +306,9 @@ Two versions: GTK or not. Take GTK.
 
 Executable name: `gvba`.
 
-Version 1.8.0 had the too fast bug: <http://askubuntu.com/questions/62611/visual-boy-advanced-emulator-runs-too-fast>. Seems unsolved.
+Version 1.8.0 had the too fast bug:
+<http://askubuntu.com/questions/62611/visual-boy-advanced-emulator-runs-too-fast>.
+Seems unsolved.
 
 ###mednafen
 

init.md

@@ -70,7 +70,7 @@ Ubuntu install before 14.04:
 
     sudo aptitude install -y chkconfig
 
-Removed in 14.04 and replaced by `sysv-rc-config`.
+Removed in 14.04 and replaced by `sysv-rc-conf`.
 
 Show table saying which service is on at which runlevel:
 
@@ -87,14 +87,44 @@ Show only for a single service:
 
 ##initctl
 
-Same as `sudo service --status-all` but for System V:
+Show status of all services:
 
     sudo initctl list
 
+Like `sudo service --status-all` but for System V.
+
+#/etc/init.d
+
+System V scripts, which will be symlinked from the `rc.d` directories.
+
+##/etc/inittab
+
+System V configuration file.
+
+Not used in Upstart.
+
 ##Ubuntu specific
 
 `/etc/defaults/name` are shell scripts that contain environment variables which can be used by the corresponding init script. Rationale: scripts can be updated without destroying parameters. File in `defaults` are never changed by the package manager.
 
+##update-rc.d
+
+CLI tool that manages System V symlinks between `/etc/rcX` and  `/etc/init.d`.
+
+Prevent a service from starting at startup (removes the symlink):
+
+    sudo update-rc.d apache2 disable
+
+Enable a service:
+
+    sudo update-rc.d apache2 defaults
+
+Set the `<start><stop>` levels of the script script:
+
+    sudo update-rc.d apache2 defaults 21
+
+The above sets start to `2` and stop to `1`.
+
 #init directory
 
 `/etc/init` is Upstart specific. It contains scripts that correspond to Upstart services.
@@ -147,33 +177,23 @@ Examples:
     sudo service apache2 restart
     sudo restart apache2
 
-##script location
-
-Some systems such as Ubuntu use upstart, newer replacement to the `system v` init system
-
--   `/etc/init`: upstart configuration files
-
-	Named services that can be used via:
+Service only works for Upstart services, it does not see System V ones.
 
-	    sudo service XXX start
+##/etc/init
 
-	correspond to:
+Upstart configuration files
 
-	    /etc/init/XXX.conf
+Named services that can be used via:
 
-	files in this directory.
+    sudo service XXX start
 
--   `/etc/init.d`: classic System V rc dirs
+correspond to:
 
-	Upstart is backwards compatible and can also understand:
+    /etc/init/XXX.conf
 
-	    /etc/init.d/XXX
+files in this directory.
 
-	as service:
-
-	    sudo service XXX start
-
-##start on
+###start on
 
 Determines event when the startup script will start.
 
@@ -191,25 +211,13 @@ To start after `/etc/fstab` mountings have been done on Ubuntu 12.04, use:
 
     start on stopped mountall
 
-##update-rc.d
-
-CLI tool that manages symlinks between `/etc/init.d` and `/etc/rcX`.
-
-Prevent a service from starting at startup (remove the symlink):
+##Disable upstart services at boot
 
-    sudo update-rc.d apache2 disable
-
-Enable a service:
-
-    sudo update-rc.d apache2 defaults
+The only way seems to be manually modifying the file to comment out the `start` line:
 
-Set the `<start><stop>` levels of the script script:
-
-    sudo update-rc.d apache2 defaults 21
-
-The above sets start to `2` and stop to `1`.
+<http://askubuntu.com/questions/19320/how-to-enable-or-disable-services>
 
-##sysv-rc-config
+##sysv-rc-conf
 
 ncurses manager of Upstart scripts.
 

perl/main.pl

@@ -321,12 +321,6 @@
         my @a = ("a0b1" =~ m/(\d)/g);
         #@a == ["0", "1"] or die;
 
-    # Loop multiple matches:
-
-        my $s = "a0";
-        $s =~ s/a(.)/b$1/ or die;
-        #$s == "b0" or die;
-
     # Almost every backslash escape has a meaning in Perl.
 
     #- `\A`: Matches only at the beginning of a string
@@ -343,7 +337,20 @@
 
     # `e` says that the replace will be an arbitrary Perl rexpression.
 
-#defalut variables
+    ##s/ operator
+
+        # Substitution:
+
+            my $s = "a0";
+            $s =~ s/a(.)/b$1/ or die;
+            $s == "b0" or die;
+
+            my $s = "a c";
+            $s =~ s/a\b/b/ or die;
+            $s == "b c" or die;
+
+
+#Defalut variables
 
     ##sources
 
@@ -406,13 +413,13 @@
 
             print $0;
 
-    ##command line arguments
+    ##Command line arguments
 
         # TODO
 
             #say $ARGV[0];
 
-    ##regex
+    ##Regex related special variables
 
         #- $1..$9 #nth capturing group of last regex match
 
@@ -424,7 +431,7 @@
 
         #- $+
 
-    ##environment
+    ##Environment
 
             say "ENV";
             foreach my $key (keys %ENV) {
@@ -582,3 +589,5 @@
 
             `true`;
             print $?, "\n";
+
+print 'ALL ASSERTS PASSED'

ubuntu/apt-file.md

@@ -0,0 +1,58 @@
+#apt-file
+
+Search for and list package files. **very** useful to know: which package provides a missing file like a `bin/name` or `include/name.h`?
+
+    sudo aptitude install apt-file
+    apt-file update
+    f=
+
+##search
+
+Search for file `"$F"` in packages.
+
+    apt-file search "$f"
+
+Literal full path substring match
+
+Use Perl regex:
+
+    apt-file search -x "a.c"
+
+Combo: search for an executable called `a2x`:
+
+    apt-file search bin/a2x
+
+##Show
+
+Shows files in package `p`:
+
+    p=
+    apt-file show "$p"
+
+##Get info on packages before installing them
+
+List package dependencies
+
+    apt-cache depends $PKG
+
+Find who depends on `$PKG` (reverse dependencies):
+
+    sudo apt-rdepends -r $PKG
+
+Get basic information about a package:
+
+    apt-cache show $PKG
+
+Get detailed information about a package:
+
+    apt-cache showpkg $PKG
+
+    sudo aptitude install debtags
+    debtags tag ls $PKG
+
+Package naming conventions:
+
+    -dev:  headers and libs, no docs
+    -doc:  documentation
+    -test: tests
+