How to reset the bash command number \#

Question

The command number in bash specifies the number of commands typed since logging in as that user to whatever terminal you have open. It can be seen in your PS1 with \#, such as in

export PS1="\! \# \\$"

I would like to reset this number at times. I can reset the history number in bash with history -c among other things but I cannot figure out how to reset the command number.

I saw someone once with a PS1 that would reset a counter to 0 whenever they typed a command with a nonzero exit status. I thought that was funny, and am trying to recreate it, as I cannot find this online. I would not like to reset the history number since this also prevents me from searching through past commands. edit: I got this functionality without resetting the command number; see here

Is there a way to display the command number in bash without PS1, or to set it somehow?

Answer 1

I'm going to say "no", or "not in bash 4.4", or "not without changing the code and re-compiling", as that value is in the variable named current_command_number, and it is only ever referenced and incremented:

$ grep -r current_command_number *.c
eval.c:extern int current_command_number, current_command_line_count, line_number;
eval.c:       current_command_number++;
shell.c:int current_command_number = 1;
shell.c:  current_command_number = 1;
y.tab.c:extern int current_command_number;
y.tab.c:              temp = itos (current_command_number);

shell.c sets it to 1 twice: during the instantiation of the variable and in the shell_reinitialize function. That function also resets the prompt, re-initializes history, and deletes all variables and functions. That function is only called once, from main().

The only external visibility to that variable is in the decode_prompt_string function, which itself is called when the prompt is supposed to be displayed or redisplayed.