Substring length in text file using Batch - batch-file

Question

In input, I have a text file which contains numbers separated with a comma.
list.txt
111221,345,332133,66,5555, and so
I want to check the length of each string between the "," delimiter, in order to successively display the length of each word.
For example:
111221 is 6 characters long
345 is 3 characters long
332133 is 6 characters long
66 is 2 characters long
...
For this, I've written this code but it displays only the first word and the length is always "0". Without the for loop, it works fine for a single chain. Has anyone an idea to fix this?
Thank you.
#echo off
setlocal enabledelayedexpansion enableextensions
for /f "delims=," %%a in ('type list.txt') do (
set string=%%a
set temp_str=%string%
set str_len=0
:loop
if defined temp_str (
set temp_str=%temp_str:~1%
set /a str_len+=1
goto:loop )
echo !string! is !str_len! characters long
)
pause
endlocal

Answer 1

#echo off
setlocal enabledelayedexpansion enableextensions
for /f "delims=" %%f in ('type q35202446.txt') do (
for %%a in (%%f) do (
set "string=%%a"
set "temp_str=!string!"
set str_len=0
CALL :loop
echo !string! is !str_len! characters long
)
)
GOTO :eof
:loop
if defined temp_str (
set temp_str=%temp_str:~1%
set /a str_len+=1
GOTO loop )
GOTO :eof
I used a file named q35202446.txt containing your data for my testing.
Your problems are :
for /f ... reads a line at a time, so delims=, would provide you with just the first token in the line. Next iteration would read the next line (if it existed)
Putting the entire line ("delims=") into %%f allows you to use the default function of , (along with space, semicolon and tab) - a separator. The for ... %%a... sees a simple list of elements separated by commas.
You must use !string! to access the run-time value of string (with delayedexpansion invoked.) %string% will deliver the parse-time value of string which will be empty, hence reporting length 0.
Note the use of quotes in the string-assignment. That syntax ensures trailing spaces are not included in the string assigned.
A label terminates a "block" (parenthesised series of statements) so I've moved the length-calculator to a subroutine.
Your echo was correctly using !var! to access the run-time value of the variables.

Answer 2

You should use for /f to read line-by-line, then an inner for to tokenize each line on the commas. Something like this:
#echo off
setlocal
for /f "usebackq delims=" %%a in ("list.txt") do (
for %%t in (%%a) do (
call :length len %%t
setlocal enabledelayedexpansion
echo %%t is !len! characters long.
endlocal
)
)
goto :EOF
:length <return_var> <string>
setlocal enabledelayedexpansion
if "%~2"=="" (set ret=0) else set ret=1
set "tmpstr=%~2"
for %%I in (4096 2048 1024 512 256 128 64 32 16 8 4 2 1) do (
if not "!tmpstr:~%%I,1!"=="" (
set /a ret += %%I
set "tmpstr=!tmpstr:~%%I!"
)
)
endlocal & set "%~1=%ret%"
goto :EOF
Credit: the :length function is based on jeb's answer here. It's much more efficient than a goto loop.