Debug printf source code with gdb on ubuntu

Debugging printf source code with gdb on ubuntu by default, the library function does not contain debugging information, so gdb cannot be used to enter the printf () function. Www.2cto.com solution: 1. install libc: sudo apt-get install libc6-dbg with debugging information 2. download libc source code. select a directory to place the source code and enter, such as/home/kent/dev-OS/libc6-source B. run sudo apt-get source libc6 to download the source code to the current directory.
The last source directory is probably:/home/kent/dev-OS/libc6-source/eglibc-2.15 www.2cto.com 3. specify the libc source directory when running gdb: gdb 'Find/home/kent/dev-OS/libc6-source/eglibc-2.15-type d-printf'-d % P' my_program 4. enter the printf () function. the first line of code I see here is va_list arg;