//KM 2018 03 23: getting lots of form spam; screen out dates before 2000 (book publication date) Reminder about PATH length | Byte Craft Limited

Reminder about PATH length

We often hear the following from frustrated customers:

"The compiler worked fine yesterday but now when I try to compile something, it tells me that there are 'undefined variables'. I haven't changed anything, so I don't know why this is happening."

Upon installing a Byte Craft compiler, the program directory of the compiler is added to your AUTOEXEC.BAT file. Other programs will often add their directories to the path as well. DOS limits the length of the system variable PATH to 256 characters, but some newer operating systems like Windows 2000 and Windows XP allow for longer ones. When a program that modifies the AUTOEXEC.BAT file from within any of these newer operating systems adds its own directory to the start of the PATH definition, the latter part, that points to the directory of the Byte Craft Limited compiler, can be truncated because it is past this 256 character limit.

To solve this problem, modify the AUTOEXEC.BAT file so that the path to the Byte Craft Limited compiler is at the start of the SET PATH= ... statement.

Other problems related to COMSPEC

If, during boot, you see DOS returning explicit errors when the AUTOEXEC.BAT is trying to set environment variables, your system may not be reserving enough memory for environment variables. Check your CONFIG.SYS for a COMSPEC line.

The COMSPEC setting in CONFIG.SYS explicitly sets the command processor (DOS shell and command prompt), and some parameters that it uses. Invoke

command.com /?

from the DOS prompt to see the switches available.

To maximize the size of the environment, input, and internal buffers reserved by command.com, change your COMSPEC line to use switches like these:

COMSPEC=c:\windows\command.com /E:32768 /L:1024 /U:255 /p