2020年12月8日(火) 10:04 Testing Purposes <raspberry.teststr...@gmail.com>: > Description: > > I just built Bash 5.1 [...], I ran "gdb bash" and entered > "print /x (int) rl_readline_version". I get "0x801" as the output. > If I do the same thing with Bash 5.0, I get "0x800". > > However, readline's online documentation at > https://tiswww.case.edu/php/chet/readline/readline.html#SEC25 - and > the "rltech.texi" file in the source code - both indicate that the > version code format should be slightly different:
1) First of all, the value of `rl_readline_version' is embedded in `bash' in the binary format, so it is meaningless to discuss whether that binary data is `0xMMmm' or `0xMmm'. 2) Next, the manual talks about the literal contained in the macro `RL_READLINE_VERSION' (defined in `lib/readline/readline.h'), which is nothing to do with the binary value of `rl_readline_version'. In fact, the macro value of `RL_READLINE_VERSION' in `readline.h' is correctly in the format of 0xMMmm as described in the manual. $ grep RL_READLINE_VERSION lib/readline/readline.h #define RL_READLINE_VERSION 0x0801 /* Readline 8.0 */ Because the information on the literal format used in the source code is lost in the executable `bash', you need to explicitly specify the format `0xMMmm' (i.e. %04x) to gdb like this: (gdb) printf "%04x\n", (int) rl_readline_version 0x0801 -- Koichi
