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iteration - How does "FOR" work in cmd batch file?

I've been programming in dozens of languages for 20 years but I could never understand how "FOR" work in windows cmd shell batch file, no matter how hard I tried. I read

http://www.amazon.com/Windows-Administration-Command-Line-Vista/dp/0470046163/ref=sr_1_1?ie=UTF8&s=books&qid=1241362727&sr=8-1

http://www.ss64.com/nt/for.html

and several other articles on the internet but still confuse and cannot accomplish anything.

Can anybody give me a concise explaination on how "FOR" works in general ?

For a little more specific question, how can I iterate through each path in %PATH% variable ? I've tried with

rem showpathenv.bat
for /f "delims=;" %%g in ("%PATH%") do echo %%g

That'd show only the first path, not all of them. Why ? What I do wrong ?

See Question&Answers more detail:os

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1 Answer

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by (71.8m points)

None of the answers actually work. I've managed to find the solution myself. This is a bit hackish, but it solve the problem for me:

echo off
setlocal enableextensions
setlocal enabledelayedexpansion
set MAX_TRIES=100
set P=%PATH%
for /L %%a in (1, 1, %MAX_TRIES%) do (
  for /F "delims=;" %%g in ("!P!") do (
    echo %%g
    set P=!P:%%g;=!
    if "!P!" == "%%g" goto :eof
  )
)

Oh ! I hate batch file programming !!

Updated

Mark's solution is simpler but it won't work with path containing whitespace. This is a little-modified version of Mark's solution

echo off
setlocal enabledelayedexpansion
set NonBlankPath=%PATH: =#%
set TabbedPath=%NonBlankPath:;= %
for %%g in (%TabbedPath%) do (
  set GG=%%g
  echo !GG:#= !
)

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