Introduced README.md

Author: cppcoffee

README.md

@@ -0,0 +1,79 @@
+# Introduce
+
+The libstacktrace is a c library that provides a simple API to output the crash call stack to **STDERR** when process crash.
+
+
+## Build
+
+```shell
+$ make
+```
+
+
+## Usage
+
+Include **stacktrace.h** to project, and call **init_stacktrace()** API to initialize library.
+
+```c
+#include "stacktrace.h"
+
+int main(int argc, char *argv[]) {
+{
+    // initialize library.
+    init_stacktrace();
+
+    // do some thing.
+}
+```
+
+
+## Example
+
+Examples of use are provided in **example.c** of the repository, which make a null pointer access and the process crashes with the following output:
+
+```shell
+[root@localhost libstacktrace]# ./example
+/home/sharp/libstacktrace/example - STACK TRACE:
+/lib64/libc.so.6(+0x36450) [0x7fca8db52450]
+./example() [0x4036f0] example.c bar()
+./example() [0x403703] example.c foo()
+./example() [0x40371d] ?? main()
+/lib64/libc.so.6(__libc_start_main+0xf5) [0x7fca8db3e555]
+./example() [0x402c9a] ?? _start()
+Segmentation fault
+```
+
+If **CCFLAGS** is add **-g** flag, more detail information will be output:
+
+```shell
+[root@localhost libstacktrace]# ./example
+/home/sharp/libstacktrace/example - STACK TRACE:
+/lib64/libc.so.6(+0x36450) [0x7fa21a2e0450]
+./example() [0x4036f0] /home/sharp/libstacktrace/example.c bar():8
+./example() [0x403703] /home/sharp/libstacktrace/example.c foo():15
+./example() [0x40371d] /home/sharp/libstacktrace/example.c main():24
+/lib64/libc.so.6(__libc_start_main+0xf5) [0x7fa21a2cc555]
+./example() [0x402c9a] ?? _start()
+Segmentation fault
+```
+
+
+## Dependence
+
+The libstacktrace dependence on **libbfd** (Binary File Descriptor library). 
+
+bfd build elf sections data, find the file name, function name and source line where the stack pointer is located based on the elf sections data.
+
+bfd is provided by the **binutils** package, which can be installed in CentOS distributions with the following command:
+
+```shell
+yum install binutils-devel -y
+```
+
+
+## Reference
+
+[https://man7.org/linux/man-pages/man1/addr2line.1.html](https://man7.org/linux/man-pages/man1/addr2line.1.html)
+
+[https://sourceware.org/binutils/docs/bfd/](https://sourceware.org/binutils/docs/bfd/)
+