Is there a way to check gcodes for errors I am getting ready to do a project that will take about 12 hours
If you used a Grbl Post (popular and proven one) GCODE errors are very unlikely. In a real world scenario you'd more likely have issues with 1) EMI 2) Windows 3) Endmills breaking 4) Stocking coming out of the clamps 5) Power failures
send $C to GRBL then send the Gcode. $C puts it into check mode. give another $C to get back to normal mode. This does do a soft reset so do check your offsets before you start the job.