Update 10 articles from html to md

11 files changed, 691 insertions, 11 deletions

diff --git a/md/writeup.md b/md/writeup.md
index fa9b397..25a0883 100644
--- a/md/writeup.md
+++ b/md/writeup.md
@@ -68,17 +68,17 @@ title: Writeup page
 [Linux antidebug 3](writeup/linux_antidebug_3.md)  
 [Linux antidebug 4](writeup/linux_antidebug_4.md)  
 [Linux antidebug 5](writeup/linux_antidebug_5.md)  
+[C C11 standard _Generic keyword](writeup/c_c11_standard_generic_keyword.md)  
+[C inline assembler](writeup/c_inline_assembler.md)  
+[Wrapping C++ exceptions, templated and classes in C](writeup/wraping_c_plus_plus_exceptions_templates_and_classes_in_c.md)  
+[Makefile tips](writeup/makefile_tips.md)  
+[AVR disassembler](writeup/avr_disassembler.md)  
+[AVR echo](writeup/avr_echo.md)   
+[Basic HTTP server](writeup/basic_http_server.md)  
+[Blender Scripts](writeup/blender_scripts.md)   
+[C Bin2Hex](writeup/c_bin2hex.md)  
+[DWM desktop environment](writeup/dwm_desktop_environment.md)  
 
-[C C11 standart _Generic keyword](http://archive.main.lv/writeup/c_c11_standart__generic_keyword.html)  
-[C inline assembler](http://archive.main.lv/writeup/c_inline_assembler.html)  
-[Wrapping C++ exceptions, templated and classes in C](http://archive.main.lv/writeup/wrapping_c___exceptions,_templated_and_classes_in_c.html)  
-[Makefile tips](http://archive.main.lv/writeup/makefile_tips.html)  
-[AVR disassembler](http://archive.main.lv/writeup/avr_disassembler.html)  
-[AVR echo](http://archive.main.lv/writeup/avr_echo.html)   
-[Basic HTTP server](http://archive.main.lv/writeup/basic_http_server.html)  
-[Blender Scripts](http://archive.main.lv/writeup/blender_scripts.html)   
-[C Bin2Hex](http://archive.main.lv/writeup/c_bin2hex.html)  
-[DWM desktop environment](http://archive.main.lv/writeup/dwm_desktop_environment.html)  
 [Assembler calculate polynom](http://archive.main.lv/writeup/assembler_calculate_polynom.html)  
 [CVE 2010-1160 Exploiting nano](http://archive.main.lv/writeup/cve_2010-1160_exploiting_nano.html)  
 [ELF rewrite function](http://archive.main.lv/writeup/elf_rewrite_function.html)  
diff --git a/md/writeup/avr_disassembler.md b/md/writeup/avr_disassembler.md
new file mode 100644
index 0000000..1ac88a9
--- /dev/null
+++ b/md/writeup/avr_disassembler.md
@@ -0,0 +1,67 @@
+title:Notes on videos
+keywords:math,statistics
+
+# AVR disassembler
+
+
+```text
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++                                AVR dissasembler                              +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++                                    INDEX                                     +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ 1. Intro
+ 2. Example
+ 3. Usage
+
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++                                     1.Intro                                  +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+
+
+Disassembler for Atmel AVR microcontrollers made for be fast and simple. No 
+extra features only basicss. Converts binary file to AVR asm output.
+
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++                                    2.Example                                 +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+
+Here is example output
+2411      CLR   0x11  
+be1f      OUT   0x3f   , 0x1    
+e5cf      LDI   0xc    , 0x5f   
+e0d4      LDI   0xd    , 0x4    
+bfde      OUT   0x3e   , 0x1d   
+bfcd      OUT   0x3d   , 0x1c   
+e010      LDI   0x1    , 0x0    
+e6a0      LDI   0xa    , 0x60   
+e0b0      LDI   0xb    , 0x0    
+ebee      LDI   0xe    , 0xbe   
+e0f0      LDI   0xf    , 0x0    
+c002      RJMP  +4    
+9005      LPM   0x0   
+920d      ST    0x0    , 0x0    
+36a0      CPI   0xa    , 0x60   
+07b1      CPC   0x1b   , 0x11   
+f7d9      BRBC  0x1    , -10 
+e010      LDI   0x1    , 0x0    
+e6a0      LDI   0xa    , 0x60   
+e0b0      LDI   0xb    , 0x0    
+c001      RJMP  +2   
+
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++                                     3.Usage                                  +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+
+disavr file.bin file.asm
+```
+
+### Links
+https://github.com/FreeArtMan/dis_avr/
+
+
+## Downloads
+dis_avr0.1.zip
+10KiB - http://archive.main.lv/files/writeup/avr_disassembler/dis_avr0.1.zip
\ No newline at end of file
diff --git a/md/writeup/avr_echo.md b/md/writeup/avr_echo.md
new file mode 100644
index 0000000..0dac9fb
--- /dev/null
+++ b/md/writeup/avr_echo.md
@@ -0,0 +1,36 @@
+title:AVR echo
+keywords:avr,echo,c,atmega
+
+
+# AVR echo
+This code tested on ATmega16
+
+```c
+#include <avr/io.h>
+ 
+#define FOSC 16000000UL
+#define BAUD 9600
+#define MYUBRR FOSC/16/BAUD-1
+ 
+void USART_Init( unsigned int ubrr)
+{
+    UBRRH = (unsigned char)(ubrr>>8);
+    UBRRL = (unsigned char)ubrr;
+    UCSRB = (1<<RXEN)|(1<<TXEN);
+    UCSRC = (1<<URSEL)|(1<<USBS)|(3<<UCSZ0);
+}
+ 
+int main()
+{
+    char c;
+    USART_Init( MYUBRR );
+    while(1)
+    {
+        while ( !(UCSRA & (1<<RXC))){};
+        c = UDR;
+        while (!(UCSRA & (1<<UDRE))){};
+        UDR = c;
+    }
+    return 0;
+}
+```
diff --git a/md/writeup/basic_http_server.md b/md/writeup/basic_http_server.md
new file mode 100644
index 0000000..cd1b4de
--- /dev/null
+++ b/md/writeup/basic_http_server.md
@@ -0,0 +1,30 @@
+title:Basic HTTP server
+keywords:c,http,server
+
+# Basic HTTP server
+Basic HTTP server. When you type url it shows listing of your local directory. If you tipe with path to file name noting hapens
+Use:
+```
+http://*.*.*.*:<port>/ -> disk start directory
+http://*.*.*.*:<port>/home/ -> home directory
+```
+Run:
+```
+./server [port]
+```
+
+Compile:
+```
+gcc server.c -o server
+```
+
+Here is also python source. It runs on port:8081 and prints in terminal HTTP request. You can see what browser sends to server.
+
+## Downloads
+servpy.zip - 
+1KiB - http://archive.main.lv/files/writeup/basic_http_server/servpy.zip  
+serverc.zip - 
+2KiB - http://archive.main.lv/files/writeup/basic_http_server/serverc.zip
+
+
+
diff --git a/md/writeup/blender_scripts.md b/md/writeup/blender_scripts.md
new file mode 100644
index 0000000..8f08f77
--- /dev/null
+++ b/md/writeup/blender_scripts.md
@@ -0,0 +1,20 @@
+title:Blender Scripts
+keywords:blender,python,scripting,fractal,koh
+
+# Blender Scripts
+Here some old blender scripts with looks that dont
+work for newest versions of blender
+
+
+## Downloads
+blender-towers.zip -
+1KiB - http://archive.main.lv/files/writeup/blender_scripts/blender-towers.zip
+towers.py.zip - 
+1KiB - http://archive.main.lv/files/writeup/blender_scripts/towers.py.zip
+
+## Images
+
+<a href=/img/blender/16.jpg width="250"><img src="http://main.lv/img/blender/16.jpg" style="width:40%" alt="blender fractal"></a>
+<a href=/img/blender/18.jpg width="250"><img src="http://main.lv/img/blender/18.jpg" style="width:40%" alt="blender fractal"></a>
+<a href=/img/blender/5.jpg width="250"><img src="http://main.lv/img/blender/5.jpg" style="width:40%" alt="blender fractal"></a>
+<a href=/img/blender/19.jpg width="250"><img src="http://main.lv/img/blender/19.jpg" style="width:40%" alt="blender fractal"></a>
\ No newline at end of file
diff --git a/md/writeup/c_bin2hex.md b/md/writeup/c_bin2hex.md
new file mode 100644
index 0000000..441a115
--- /dev/null
+++ b/md/writeup/c_bin2hex.md
@@ -0,0 +1,18 @@
+title:C Bin2Hex
+keywords:c,binary,hex
+
+# C Bin2Hex
+Converts binary file to hex file.
+
+Use:
+```
+./bin2hex [bin_file] - for local output
+
+./bin2hex [bin_file] [hex_text_file] - for file output
+```
+
+
+### Downloads
+abin2hex.tar.gz -
+1KiB - http://archive.main.lv/files/writeup/c_bin2hex/abin2hex.tar.gz  
+
diff --git a/md/writeup/c_c11_standard_generic_keyword.md b/md/writeup/c_c11_standard_generic_keyword.md
new file mode 100644
index 0000000..639264c
--- /dev/null
+++ b/md/writeup/c_c11_standard_generic_keyword.md
@@ -0,0 +1,104 @@
+title:C C11 standart _Generic keyword
+keywords:c,c11,generic
+
+
+# C C11 standart _Generic keyword
+
+## INTRO
+
+
+In C standart c11 is supported new keyword _Generic. It add way how
+we can add at macro level decisitions about variable types. And now is
+possible make some C++ like function "overloading". Here is some variants how
+to use this generic "_Generic". Now could print variables dont looking
+on its type _Generic will deal with it.
+
+
+## EXAMPLES
+
+Detect type
+
+```c
+#define type_str(T) _Generic( (T), int: "int",\
+long: "long",\
+default: "Unknown type")
+```
+
+Now we have define check for 2 types int and long. If there is some type
+undefined then choose default type and print "Unknown type". This is auto
+printf example where you can detect type and print its name. But as in page [1]
+you can add number values and compare types in simple way.
+
+```c
+printf("Type1 %s\n", type_str('a'));
+printf("Type2 %s\n", type_str(1));
+printf("Type3 %s\n", type_str(1l));
+printf("Type4 %s\n", type_str(0.0f));
+```
+
+Also is possible to use generic for 2 or more types but then amount
+of declaration grows. But it means that now according to params
+we can choose best function.
+
+```c
+#define type_str2(T1,T2) _Generic( (T1),\
+int: _Generic((T2),int:"int int", default: "int UNK"),\
+default: "UNK UNK" )
+ 
+printf("Double Type 1 %s\n", type_str2(1,1));
+printf("Double Type 2 %s\n", type_str2(1,0.0f));
+printf("Double Type 3 %s\n", type_str2(.0f,.0f));
+```
+
+Check if types is compatible
+
+
+Strange but some types could be invalid if there is const used, like
+'int' and 'const int'.
+
+```c
+#define is_compatible(x,T) _Generic((x), T:"compatible",\
+default: "non-compatible")
+```
+
+Here is defined 2 types and only (int and int) and (const int and const int)
+is compatible.
+
+```c
+int i1;
+const int i2;
+printf("int       == int,       %s\n", is_compatible(i1,int));
+printf("const int == const int, %s\n", is_compatible(i2,const int));
+printf("int       == const int, %s\n", is_compatible(i1,const int));
+printf("const int == int,       %s\n", is_compatible(i2,int));
+```
+
+
+
+## TESTED
+
+gcc-4.9.1  
+clang-3.4
+
+
+## FILES
+
+ex1.c - one argument generic  
+ex2.c - two argument generic  
+ex3.c - check for compatibility
+
+
+## Links
+http://www.robertgamble.net/2012/01/c11-generic-selections.html  
+http://en.wikipedia.org/wiki/C11_%28C_standard_revision%29  
+https://gcc.gnu.org/wiki/C11Status  
+
+## Downloads
+ex3.c -
+1KiB - http://archive.main.lv/files/writeup/c_c11_standart__generic_keyword/ex3.c  
+ex1.c -
+1KiB - http://archive.main.lv/files/writeup/c_c11_standart__generic_keyword/ex1.c  
+ex2.c - 
+1KiB - http://archive.main.lv/files/writeup/c_c11_standart__generic_keyword/ex2.c  
+source.tar.gz -
+1KiB - http://archive.main.lv/files/writeup/c_c11_standart__generic_keyword/source.tar.gz  
\ No newline at end of file
diff --git a/md/writeup/c_inline_assembler.md b/md/writeup/c_inline_assembler.md
new file mode 100644
index 0000000..5566192
--- /dev/null
+++ b/md/writeup/c_inline_assembler.md
@@ -0,0 +1,105 @@
+title:C inline assembler
+keywords:c,inline,assembler
+
+
+# C inline assembler
+There is long time since I wanted to learn "creepy" gcc inline assembly.
+Looking at manuals its not so hard and "creepy". Using it is more
+interesting and dissambly of compiled code is very nice looking.
+
+volatile puts our asm code where it is and don't optimize it without
+volatile it can optimize.
+
+What to write in __asm__ directive looks like this
+
+```c
+__asm__ __volatile__("our_code":output:input:used)
+```
+
+as code to convert to inline asm we will use last post [2].
+
+There is only one instruction that we using and it usage was
+
+```c
+get_timer:
+    rdtsc
+    ret
+```
+
+its not very optimal and for 1 instruction writing whole function
+its not beautiful. We remember that returning result of this function is
+saved in eax register.
+
+```c
+__asm__ __volatile__("rdtsc":"=a"(x)::)
+```
+
+code looks like this. But we can make it as define function
+
+```c
+#define get_timer(X) __asm__ __volatile__("rdtsc":"=a"(X)::)
+```
+
+This code works fine and give 70058 ticks on cycle
+When adding option -O2 then result becomes wherry strange.
+
+As we remember that rdtsc return result in edx:eax then we add to
+used registers(clobber) %edx.
+
+```c
+#define get_timer(X) __asm__ __volatile__("rdtsc":"=a"(X)::"%edx")
+```
+
+And also we can rewrite everything as
+inline function.
+
+```c
+static inline unsigned int get_timeri()
+{
+    unsigned int i;
+    __asm__ __volatile__("rdtsc":"=a"(i)::);
+    return i;
+}
+```
+
+
+Now this two functions works fine with -O options.
+When empty cycle is optimized then it becomes empty and resulting
+tick number is 32 for both inline function and define macro.
+It not working for his main purpose. When no optimization switched
+then get_timer works for some ticks faster then get_timeri.
+
+We can add attribute always inline and we will win some ticks
+and function will always inline regards optimization level
+
+```c
+__attribute__((always_inline)) unsigned int get_timeri() 
+```
+
+Too fix test cycle for our measurement we make it as object file
+and it will compiled without options.
+
+```c
+void fixed_cycle()
+{
+    int i;
+    for (i=0;i<10000;i++)
+    {
+    }
+}
+```
+
+Now everything looks quite good and also inline assembly works as expected.
+
+For reference about inline asm you can go to [1]
+
+
+
+## Links
+http://www.ibiblio.org/gferg/ldp/GCC-Inline-Assembly-HOWTO.html
+
+## Downloads
+asm_inline.zip -
+3KiB - http://archive.main.lv/files/writeup/c_inline_assembler/asm_inline.zip  
+dis_avr0.1.zip -
+10KiB - http://archive.main.lv/files/writeup/c_inline_assembler/dis_avr0.1.zip  
\ No newline at end of file
diff --git a/md/writeup/dwm_desktop_environment.md b/md/writeup/dwm_desktop_environment.md
new file mode 100644
index 0000000..47a0951
--- /dev/null
+++ b/md/writeup/dwm_desktop_environment.md
@@ -0,0 +1,64 @@
+title:DWM desktop environment
+keywords:dwm,pertag,pango,systemtray
+
+# DWM desktop environment
+
+## INTRO
+
+DWM is minimalistic tiling manager it contain only few thousand lines of
+code. It main idea is to be simple as possible and usable as possible.
+It has only minimal features and if you want to extend it you need to
+edit dwm C source config file or add some patches from dwm project
+web page. You dont need to use mouse to use dwm all actions can be done
+with keyboard.
+
+## GOAL
+
+Make dwm fork with some useful minimalistic stuff like dwmstatus
+program that show system statuses. And allow to switch on/off dwm
+patches with linux kernel menuconfig(without menuconfig everything
+works).
+Next thing to add is some minimalistic screenlock, screensaver
+and login. At then end there could be minimalistic "suckless" desktop
+environment with all things needed. All parts are as separate
+repositories and can be used independently.
+
+## CHANGELOG
+### [2014.07.10]  
+dwmstatus  
+[+]add temperature status  
+[+]add current CPU usage status  
+[+]add battery/AC status  
+
+### [2014.07.03]  
+dwm branch 6.0  
+[+] added pango patch  
+[+] added systemtray patch  
+[+] added pertag patch  
+[+] menuconfig support  
+dwmstatus  
+[+] added time status  
+[+] added date status  
+[+] menuconfig support  
+
+
+## Links
+http://dwm.suckless.org/  
+http://dwm.suckless.org/dwmstatus/  
+http://dwm.suckless.org/patches/  
+https://github.com/FreeArtMan/dwm-fancy  
+https://github.com/FreeArtMan/dwmstatus-fancy  
+https://www.kernel.org/  
+http://en.wikipedia.org/wiki/Menuconfig  
+
+## Downloads
+dwmstatus-fancy-0.1.tar.gz -
+105KiB - http://archive.main.lv/files/writeup/dwm_desktop_environment/dwmstatus-fancy-0.1.tar.gz  
+dwm-fancy-0.1.tar.gz -
+28KiB - http://archive.main.lv/files/writeup/dwm_desktop_environment/dwm-fancy-0.1.tar.gz  
+
+## Images
+
+<a href=/img/dwm/dwm-0.1.png width="250"><img src="http://main.lv/img/dwm/dwm-0.1.png" style="width:40%" alt="dwm workspace"></a>
+<a href=/img/dwm/dwm-fancy-0.1.png width="250"><img src="http://main.lv/img/dwm/dwm-fancy-0.1.png" style="width:40%" alt="dwm workspace"></a>
+<a href=/img/dwm/dwmstatus-fancy-0.1.png width="250"><img src="http://main.lv/img/dwm/dwmstatus-fancy-0.1.png" style="width:40%" alt="dwm workspace"></a>
\ No newline at end of file
diff --git a/md/writeup/wraping_c_plus_plus_exceptions_templates_and_classes_in_c.md b/md/writeup/wraping_c_plus_plus_exceptions_templates_and_classes_in_c.md
new file mode 100644
index 0000000..0f43f21
--- /dev/null
+++ b/md/writeup/wraping_c_plus_plus_exceptions_templates_and_classes_in_c.md
@@ -0,0 +1,236 @@
+title:Wrapping C++ exceptions, templated and classes in C
+keywords:c++,c,exeptions,templates,classes
+
+# Wrapping C++ exceptions, templated and classes in C
+
+Sometime some libraries is distributed only as C++ libs or in template
+code. Or plug-ins for some programs is only in C or other language.
+
+Here can join C and C++ compiled code and there will no big difference
+with language you use. Only need to choose right compiler for compilation.
+C++ stuff can be easily hidden and you can use some C++ "only" features
+in C without notice it.
+
+Use templates from C.
+
+
+Templates is most C++'sh part of all. Templates are defined in C++ headers
+and there not generate code. Only when you use they generate code.
+It reason why cannot include them inside *.so or *.a libraries.
+But you can always generated templates function examples that will
+generate code. And it means it now can be inside *.so and *.a.
+To use templates from C and compile it with C we need to hide C++ headers
+from C and create templates generated code
+
+C compatible header code.h
+
+```c
+extern float cmpx_add_f(float, float);
+extern int   cmpx_add_i( int, int );
+```
+
+C++ template code.hpp
+
+```c
+template <typename T>
+inline T cmpx_add( T a, T b )
+{
+    return a+b;
+}
+```
+
+Tell C++ to generate code for specific templates code.hpp
+
+```c
+template int cmpx_add<int>(int, int);
+template float cmpx_add<float>(float, float);
+```
+
+Write C compatible wrapper in C++
+
+```c
+float cmpx_add_f( float a, float b )
+{
+    return cmpx_add<float>(a,b);
+}
+ 
+int cmpx_add_i( int a, int b )
+{
+    return cmpx_add<int>(a,b);
+}
+```
+
+lets see now object file info
+```
+readelf -a
+```
+
+```c
+18: 0000000000000000 63 FUNC GLOBAL DEFAULT 5 cmpx_add_f
+20: 0000000000000000 42 FUNC WEAK DEFAULT 13 _Z8cmpx_addIfET_S0_S0_
+21: 000000000000003f 31 FUNC GLOBAL DEFAULT 5 cmpx_add_i
+22: 0000000000000000 20 FUNC WEAK DEFAULT 12 _Z8cmpx_addIiET_S0_S0_
+```
+
+We see that functions inside code.h is globally visible and we can use them
+without problem from C.
+
+Use C++ exceptions
+
+
+Exceptions is usually very C++'sh everyone know that exceptions cannot be
+used in C. There is some C libraries that add some kind exceptions for
+C. That libraries usually uses setjmp and longjmp for simulating that kind of stuff.
+
+C header
+
+```c
+extern void  raise_exception( int );
+```
+
+C++ code for raising exceptions
+
+```c
+extern void raise_exception( int a )
+{
+    try
+    {
+        int b;
+        b = b/a;
+        printf("Everything ok ;]\n");
+    }
+    catch ( int e )
+    {
+        printf("Catching up exception number %d \n",e);
+    }
+}
+```
+
+C use exceptions
+
+```c
+raise_exception( 1 );
+raise_exception( 0 );
+```
+
+Here is seen that C++ exception raises inside C code. There can be made
+some code additions and C++ exceptions can be used in C with some tricks.
+Not yet proof of concept. But with pointers to functions
+(wasn't they called callbacks?) it cone be done.
+
+Use C++ classes
+
+
+C completable headers
+
+```c
+extern void* clA_init();
+extern void  clA_add( void*,int, int );
+extern int   clA_empty( void* );
+extern void  clA_destroy( void* );
+```
+
+C++ class definitions
+
+```c
+class A
+{
+    public:
+        char *p;
+        A();
+        ~A();
+        void add( int, int );
+        bool empty();
+};
+```
+
+C++ class implementation
+
+```c
+A::A()
+{
+    this->p = (char *)malloc(1024);
+}
+ 
+A::~A()
+{
+    printf("Free Class Baby!!!\n");
+    if (this->p != NULL)
+    {
+        free( this->p);
+    }
+}
+ 
+void A::add( int a, int b )
+{
+    int i = cmpx_add_i( a , b );
+    printf("%d\n", i);
+}
+ 
+bool A::empty()
+{
+    if (this->p == NULL)
+    {
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}
+```
+
+C++ wrapping functions
+
+```c
+extern void* clA_init()
+{
+    A *a = new A;
+    return (void *)a;
+}
+ 
+ 
+extern void clA_add( void *c, int a, int b )
+{
+    A *cl=(A*)c;
+    cl->add( a, b );
+}
+ 
+extern int clA_empty( void *c )
+{
+    A *cl=(A*)c;
+    bool b = cl->empty();
+    if ( b == true ) 
+    {
+        return 1;
+    } else
+    {
+        return 0;
+    }
+}
+ 
+extern void clA_destroy( void *c )
+{
+    A *cl = (A*)c;
+    cl->~A();
+}
+```
+
+It easy to give C++ class to C as void* and then use
+C++ class functions (wasnt they called methods?) from C
+simply as pointers. It segfault oriented but it the way how it works.
+
+These examples shows that you can stay as much as possible with C
+and use C++ compiled code.
+
+
+## Links
+http://linux.die.net/man/1/readelf  
+http://gcc.gnu.org/codingconventions.html#ExternC  
+http://www.cplusplus.com/doc/tutorial/classes/  
+http://linux.die.net/man/3/setjmp  
+http://linux.die.net/man/3/longjmp  
+
+## Downloads
+c_cpp_tricks.tar.gz -
+2KiB -  http://archive.main.lv/files/writeup/wrapping_c___exceptions,_templated_and_classes_in_c/c_cpp_tricks.tar.gz  
diff --git a/md/writeup/x11_prototype_gui.md b/md/writeup/x11_prototype_gui.md
index 8576ce1..7b69094 100644
--- a/md/writeup/x11_prototype_gui.md
+++ b/md/writeup/x11_prototype_gui.md
@@ -35,7 +35,7 @@ http://www.x.org/wiki/ProgrammingDocumentation/
 http://archive.main.lv/files/writeup/x11_prototype_gui/xlib_proto_gui.tar.gz
 
 
-![GUI](/img/x11_gui/gui.png)
+<a href=/img/x11_gui/gui.png width="250"><img src="/img/x11_gui/gui.png" style="width:40%" alt="GUI"></a>