Add info about GDB.

diff --git a/docs/pfd.gpg b/docs/pfd.gpg
new file mode 100644 (file)
index 0000000..d6b98af
Binary files /dev/null and b/docs/pfd.gpg differ

diff --git a/docs/unix-linux/dev/_category_.json b/docs/unix-linux/dev/_category_.json
new file mode 100644 (file)
index 0000000..af63425
--- /dev/null
+++ b/docs/unix-linux/dev/_category_.json
@@ -0,0 +1,7 @@
+{
+  "label": "Linux/Unix Developement",
+  "link": {
+    "type": "generated-index",
+    "description": "Useful information about all that's related to unix/linux developement."
+  }
+}

diff --git a/docs/unix-linux/dev/gdb.md b/docs/unix-linux/dev/gdb.md
new file mode 100644 (file)
index 0000000..731146f
--- /dev/null
+++ b/docs/unix-linux/dev/gdb.md
@@ -0,0 +1,177 @@
+---
+tags:
+    - linux
+    - unix
+    - gdb
+    - dev
+---
+
+# GDB
+
+GDB, the GNU Project debugger, allows you to see what is going on `inside' another program while it executes.
+Or what another program was doing at the moment it crashed.
+
+## Useful commands
+
+### Build
+
+```bash title="Compile program with debug-symbols"
+$ g++ -g main.cpp -o bin
+```
+
+### Debug
+
+```bash title="run gnu debugger"
+$ gdb bin
+```
+
+```bash title="check information about arch and sections"
+(gdb) info file
+```
+
+```bash title="get list of functions"
+@(gdb) i func
+All defined functions:
+
+File demo-one.c:
+3:      int main();
+
+Non-debugging symbols:
+0x0000000000001000  _init
+0x0000000000001030  puts@plt
+0x0000000000001040  printf@plt
+0x0000000000001050  __isoc99_scanf@plt
+0x0000000000001060  _start
+0x00000000000011b0  _fini
+```
+
+```bash title="set breakpoint on main function"
+@(gdb) b main
+Breakpoint 1 at 0x1141: file demo-two.c, line 4.
+```
+
+```bash title="check information about breakpoints"
+@(gdb) i b
+Num     Type           Disp Enb Address            What
+2       breakpoint     keep y   0x0000000000001168 in main at demo-one.c:6
+3       breakpoint     keep y   0x0000000000001177 in main at demo-one.c:7
+```
+
+```bash title="other useful breakpoints commands"
+disable/enable breakpoint_number    // disable/enable
+delete breakpoint_number            // delete
+ignore breakpoint_number n          // stop on breakpoint after executing it n times
+```
+
+```bash title="run program"
+@(gdb) r
+Starting program: /home/dima/dev/c/gdb-demo/demo-two
+[Thread debugging using libthread_db enabled]
+Using host libthread_db library "/usr/lib/libthread_db.so.1".
+
+Breakpoint 1, main () at demo-two.c:4
+4         int value1 = 5;
+```
+
+```bash title="step into"
+@(gdb) s
+5         int value2 = 10;
+```
+
+```bash title="step over line"
+@(gdb) n
+7         int result = value1 + value2;
+```
+
+```bash title="step over instruction(assembly instruction)"
+@(gdb) ni
+```
+
+```bash title="print values"
+@(gdb) p value1
+$1 = 5
+@(gdb) p value2
+$2 = 10
+```
+
+```bash title="display value"
+@(gdb) disp value1
+1: value1 = 5
+@(gdb) disp result
+2: result = 32767
+@(gdb) s
+9         printf("Sum of %d and %d is %d\n", value1, value2, result);
+1: value1 = 5
+2: result = 15
+```
+
+```bash title="quit gdb"
+@(gdb) q
+```
+
+```bash title="set breakpoint on particular string of particular file"
+@(gdb) b demo-two.c:7
+Breakpoint 1 at 0x114f: file demo-two.c, line 7.
+@(gdb) r
+Starting program: /home/dima/dev/c/gdb-demo/demo-two
+[Thread debugging using libthread_db enabled]
+Using host libthread_db library "/usr/lib/libthread_db.so.1".
+
+Breakpoint 1, main () at demo-two.c:7
+7         int result = value1 + value2;
+```
+
+```bash title="continue programm running"
+@(gdb) c
+Continuing.
+Sum of 5 and 10 is 15
+[Inferior 1 (process 50807) exited normally]
+```
+
+```bash title="list 10 code lines of current location"
+@(gdb) l
+2
+3       int main() {
+4         int value1 = 5;
+5         int value2 = 10;
+6
+7         int result = value1 + value2;
+8
+9         printf("Sum of %d and %d is %d\n", value1, value2, result);
+10
+11        return 0;
+```
+
+```bash title="more detail views(source code, assembler, registers)"
+@(gdb) lay next
+@(gdb) lay src
+@(gdb) lay asm
+@(gdb) lay regs
+```
+
+```bash title="refresh the screen"
+@(gdb) ref
+```
+
+```bash title="print the back trace"
+@(gdb) bt
+#0  0x00007ffff7e16736 in __vfscanf_internal (s=<optimized out>, format=<optimized out>, argptr=argptr@entry=0x7fffffffd9c0, mode_flags=mode_flags@entry=2) at vfscanf-internal.c:1976
+#1  0x00007ffff7e04986 in __isoc99_scanf (format=<optimized out>) at isoc99_scanf.c:30
+#2  0x0000555555555190 in main () at demo-one.c:7
+```
+
+```bash title="examine memory"
+@(gdb) x/i $pc
+=> 0x7ffff7e16736 <__vfscanf_internal+22086>:   mov    %edx,(%rax)
+
+x/i - instruction
+x/x - hex
+x/s - string
+x/a - address
+
+x/b - 8-bit
+x/h - 16-bit
+x/w - 32-bit
+x/g - 64-bit
+```
+

diff --git a/static/img/proxy/3xui.gpg b/static/img/proxy/3xui.gpg
new file mode 100644 (file)
index 0000000..3673e12
Binary files /dev/null and b/static/img/proxy/3xui.gpg differ