Does sprintf truncate extra charecters if the destination buffer overflow?

float initial_temp_setpoint = 60;

sprintf(
bc_buffer, "\n\rVTM: NOT bc_vap_state_off: bc_cf_auto_vap_standby_enable: NOT bc_vap_standby_warmup_completed: warmup time=INC: setpoint<ALI3_STARTUP_COOL: initial_temp_setpoint from bc_vap_standby_temp=AT_ALI3_STARTUP_COOL_DEF_TEMP=%f",initial_temp_setpoint);

Quote:

VTM: NOT bc_vap_state_off: bc_cf_auto_vap_standby_enable: NOT bc_vap_standby_warmup_completed: warmup time=INC: setpoint<ali3_startup_cool: initial_temp_setpoint="" from=""
bc_vap_standby_temp="AT_ALI3_STARTUP_COOL_DEF_TEMP=60.000000</blockquote">

I was expecting a crash. I was thinking to fix this by using snprintf, so that memory overflow could be avoided.

But that would result in a truncated log. So, i was thinking to increase the size of bc_buffer including a NULL charecter. But as it is a global variable, i am a little apprehensive as i do not want to play with a global data and it could also affect the memory map.

Could this behaivour be compiler related?

I would request for suggestions.

Thanks,
Rahul VB

What I have tried:

I tried out the above code in eclipse and Visual studio, but it prints the entire string and not truncated.

I also set a break point to view the data of bc_buffer as below:

(x)=bc_buffer[197] char 83 'S'
(x)=bc_buffer[198] char 84 'T'
(x)=bc_buffer[199] char 65 'A'

As you can see above the last charecter is 'A' and no NULL charecter, still it does print the entire string of 223 bytes.