How to find the path for a given file

The $PATH is searched from beginning to end, with the first matching executable being run. So directories at the beginning of $PATH take precedence over those that come later. Executables in the current directory (.) are only executed if . is in $PATH (which it usually isn't). There is no implicit inclusion of the current directory in the search path.

Here is a windows batch file that will search your path for a file. I have tested it on XP and Win7.

Please understand that a batch/command file is NOT a good solution to this problem because string manipulation is painfully slow - but in lieu of a compiled tool, this will do what you desire.

Hopefully it is commented well enough, but feel free to ask questions if anything needs clarification.

@echo off

SETLOCAL ENABLEDELAYEDEXPANSION

rem -- SRC = Search value. Eg. notepad  or  notepad.exe
rem -- PAT = A copy of the path
rem -- SEP = PATH seperator
rem -- EXE = Executable file extensions
SET TMP_SRC=%1
SET TMP_PAT=%PATH%
SET TMP_SEP=;
SET TMP_EXE=exe com bat cmd

rem -- This is a batch file ...they are s-l-o-w
rem -- "<nul set /p=" does "echo" without a newline
<nul set /p =Searching...

:strLoop
    rem -- SUB = The first entry in the current PATH
    for /f "delims=%TMP_SEP%" %%s in ("!TMP_PAT!") do set TMP_SUB=%%s

    rem -- Progress update
    <nul set /p =.

    rem -- Check for the file exactly as specified on the command line
    if exist "!TMP_SUB!\%TMP_SRC%" (
        echo.
        echo Found "!TMP_SUB!\%TMP_SRC%"
        goto strDone
    )

    rem -- Check for the file with each of the selected executable extensions
    for %%x in (%TMP_EXE%) do (
        if exist "!TMP_SUB!\%TMP_SRC%.%%x" (
            echo.
            echo Found "!TMP_SUB!\%TMP_SRC%.%%x"
            goto strDone
        )
    )

    rem -- This loop chops off the first entry of the PATH
:subLoop
    rem -- CHR = First character of current PATH
    rem -- PAT -> All but the first character of the current PATH
    set TMP_CHR=!TMP_PAT:~0,1!
    set TMP_PAT=!TMP_PAT:~1!

    rem -- Have we exhausted the PATH?
    if "!TMP_PAT!" EQU "" goto strDone

    rem -- Have we just removed a PATH seperator?
    if "!TMP_CHR!" EQU "%TMP_SEP%" goto strLoop

    rem -- Keep stripping characters
    goto subLoop
:strDone

rem -- Cleanup
SET TMP_SRC=
SET TMP_PAT=
SET TMP_SEP=
SET TMP_SUB=
SET TMP_CHR=
SET TMP_EXE=

ENDLOCAL