Loop through ASCII codes in batch file

Loop through ASCII codes in batch file

Any batch solution to do what you want would be much more complex than what you already have.

Consider using PowerShell instead:

for($i=65;$i -le 90; $i++){[char]$i}

Example output:

PS F:\test> for($i=65;$i -le 90; $i++){[char]$i}
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z

Surprisingly, there is a solution that makes use of an undocumented built-in environment variable named =ExitCodeAscii, which holds the ASCII character of the current exit code¹ (ErrorLevel):

@echo off
for /L %%A in (65,1,90) do (
    cmd /C exit %%A
    call echo %%^=ExitCodeAscii%%
)

The for /L loop walks through the (decimal) character codes of A to Z. cmd /C exit %%A sets the return code (ErrorLevel) to the currently iterated code, which is echo-ed as a character afterwards. call, together with the double-%-signs introduce a second parsing phase for the command line in order to get the current value of =ExitCodeAscii rather than the one present before the entire for /L loop is executed (this would happen with a simple command line like echo %=ExitCodeAscii%). Alternatively, delayed expansion could be used also.

The basic idea is credited to rojo and applied in this post: How do i get a random letter output in batch.

_{1) The exit code (or return code) is not necessarily the same thing as the ErrorLevel value. However, the command line cmd /C exit 1 sets both values to 1. To ensure that the exit code equals ErrorLevel, use something like cmd /C exit %ErrorLevel%.}