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10.9 Pretty Printing

gdb provides a mechanism to allow pretty-printing of values using Python code. It greatly simplifies the display of complex objects. This mechanism works for both MI and the CLI.

For example, here is how a C++ std::string looks without a pretty-printer:

     (gdb) print s
     $1 = {
       static npos = 4294967295,
       _M_dataplus = {
         <std::allocator<char>> = {
           <__gnu_cxx::new_allocator<char>> = {
             <No data fields>}, <No data fields>
         members of std::basic_string<char, std::char_traits<char>,
           std::allocator<char> >::_Alloc_hider:
         _M_p = 0x804a014 "abcd"

With a pretty-printer for std::string only the contents are printed:

     (gdb) print s
     $2 = "abcd"

For implementing pretty printers for new types you should read the Python API details (see Pretty Printing API).