Debug directly in vim

TL;DL you can use gdb directly from vim without installing any

extensions. Just compile your program with debug options and do:

:packadd termdebug

:TermdebugCommand path-to-my-program

Now the actual notes:

If you actually listened to the show, I am sorry for how long it took

me to realize that I was compiling without debug flags.

This is not a good overview of gdb, I don't think, for

that I would recommend episode

415 on Klaatu's Gnu World Order podcast.

The program that we build up to is this:

// file: main.c

#include <stdio.h>

#include <string.h>

void greet(char* greeting)

{

- int end = strlen(greeting);

+ int end = strlen(greeting) - 1;

if (greeting[end] == '

')

printf("%s", greeting);

else

printf("%s

", greeting);

}

int main ()

{

greet( "Hello world!

");

return 0;

}

Where we use gdb to find out that we are checking one character past

the end in the if-condition rather than the last character, this then

results in a double new-line.

Once the debugger is launched within vim, termdebug offers a few ways

to control the debugging, namely:

:Source - focus on source window. :Gdb -

focus on debugger window. :Program - focus on program

output window :Break - introduce a break point in line

under the cursor (in the source window) :Clear - clear the

break point in the line under the cursor. :Evaluate - show

the value of the expression under the cursor.

... And a good deal more, if you're interested just have a gander at

:help termdebug.

I hope this helps someone make their debugging experience slightly

less painful, as it has helped me recently :)