Get listening port of process OR listening port to process.

glpp.bat

@echo off
setlocal EnableDelayedExpansion


call :InitColors

if "%~1"=="" goto usage
if /i "%~1"=="--help" goto usage
if /i "%~1"=="-h" goto usage
if /i "%~1"=="/?" goto usage

set "arg1=%~1"

rem Check if argument is a port number (digits only)
echo %arg1%| findstr /r "^[1-9][0-9]*$" >nul
if not errorlevel 1 (
    if %arg1% GTR 65535 (
        echo %RED%Error: Port number must be between 1 and 65535%RST%
        exit /b 1
    )
    call :FindProcessByPort %arg1%
    exit /b
)


call :ValidateEnvironment
if errorlevel 1 exit /b 1

rem Sanitize and normalize process name
set "procname=%arg1%"
call :SanitizeInput "!procname!" procname
call :NormalizeProcessName "!procname!" procname

echo %BLU%Searching for process: %procname%...%RST%

call :CreateTempFiles
if errorlevel 1 (
    echo %RED%Error: Cannot create temporary files%RST%
    exit /b 1
)


tasklist /fi "imagename eq %procname%" /fo csv /nh > "%tmp_pids%" 2>nul
if errorlevel 1 (
    echo %RED%Error: Failed to query process list%RST%
    call :Cleanup
    exit /b 1
)

rem Check if any processes found
>nul 2>&1 findstr /r "." "%tmp_pids%"
if errorlevel 1 (
    echo %YEL%No process found with name: %procname%%RST%
    call :Cleanup
    exit /b 0
)


rem Get network information once

echo %BLU%Gathering network information...%RST%
netstat -ano > "%tmp_netstat%" 2>nul
if errorlevel 1 (
    echo %RED%Error: Failed to get network information%RST%
    call :Cleanup
    exit /b 1
)


rem Process results
call :ProcessResults
call :Cleanup
exit /b 0


rem Initialize color codes
:InitColors
set "COLOR_ENABLED=0"
if not "%WT_SESSION%"=="" set "COLOR_ENABLED=1"
if "%TERM%"=="xterm" set "COLOR_ENABLED=1"
if "%TERM%"=="xterm-256color" set "COLOR_ENABLED=1"
if "%ConEmuANSI%"=="ON" set "COLOR_ENABLED=1"

if "%COLOR_ENABLED%"=="1" (
    for /f "delims=#" %%E in ('"prompt #$E# & for %%E in (1) do rem"') do set "ESC=%%E"
    set "RED=!ESC![1;31m"
    set "GRN=!ESC![1;32m"
    set "YEL=!ESC![1;33m"
    set "BLU=!ESC![1;34m"
    set "CYN=!ESC![1;36m"
    set "WHT=!ESC![1;37m"
    set "RST=!ESC![0m"
) else (
    set "RED=" & set "GRN=" & set "YEL=" & set "BLU=" & set "CYN=" & set "WHT=" & set "RST="
)
exit /b 0

rem Validate system environment
:ValidateEnvironment
where tasklist >nul 2>&1
if errorlevel 1 (
    echo %RED%Error: tasklist command not available%RST%
    exit /b 1
)

where netstat >nul 2>&1
if errorlevel 1 (
    echo %RED%Error: netstat command not available%RST%
    exit /b 1
)

if not exist "%TEMP%" (
    echo %RED%Error: Temporary directory not accessible%RST%
    exit /b 1
)
exit /b 0

rem Sanitize input to prevent injection
:SanitizeInput
set "input=%~1"
set "input=%input:"=%"
set "input=%input:<=_%"
set "input=%input:>=_%"
set "input=%input:|=_%"
set "input=%input:&=_%"
set "input=%input:^=_%"
set "%~2=%input%"
exit /b 0

rem Normalize process name (add .exe, convert to lowercase)
:NormalizeProcessName
set "name=%~1"
if /i not "!name:~-4!"==".exe" set "name=!name!.exe"
call :FastToLower "!name!" name
set "%~2=%name%"
exit /b 0

rem Fast lowercase conversion using substitution
:FastToLower
set "str=%~1"
set "str=%str:A=a%" & set "str=%str:B=b%" & set "str=%str:C=c%" & set "str=%str:D=d%"
set "str=%str:E=e%" & set "str=%str:F=f%" & set "str=%str:G=g%" & set "str=%str:H=h%"
set "str=%str:I=i%" & set "str=%str:J=j%" & set "str=%str:K=k%" & set "str=%str:L=l%"
set "str=%str:M=m%" & set "str=%str:N=n%" & set "str=%str:O=o%" & set "str=%str:P=p%"
set "str=%str:Q=q%" & set "str=%str:R=r%" & set "str=%str:S=s%" & set "str=%str:T=t%"
set "str=%str:U=u%" & set "str=%str:V=v%" & set "str=%str:W=w%" & set "str=%str:X=x%"
set "str=%str:Y=y%" & set "str=%str:Z=z%"
set "%~2=%str%"
exit /b 0

:CreateTempFiles
set "session_id=%RANDOM%_%RANDOM%"
set "tmp_pids=%TEMP%\pids_%session_id%.txt"
set "tmp_netstat=%TEMP%\netstat_%session_id%.txt"

rem Test if we can create files
echo test > "%tmp_pids%" 2>nul
if errorlevel 1 exit /b 1
del /f /q "%tmp_pids%" >nul 2>&1
exit /b 0


:ProcessResults
setlocal EnableDelayedExpansion
set "proc_count=0"
echo.

for /f "usebackq tokens=1,2,5 delims=," %%a in ("%tmp_pids%") do (
    set "pname=%%~a"
    set "pid=%%~b"
    set "memory=%%~c"
    
    set /a proc_count+=1
    
    echo %GRN%[!proc_count!] Process: !pname! ^(PID: !pid!, Memory: !memory!^)%RST%
    echo %CYN%    Listening ports:%RST%
    echo     Proto  Local Address          Foreign Address        State           PID
    echo     -----  -------------          ---------------        -----           ---
    
    set "found_ports=0"
    for /f "usebackq tokens=*" %%l in (`findstr /r /c:"LISTENING" "%tmp_netstat%" ^| findstr /r /c:" !pid!$" ^| findstr /v /c:"["`) do (
        echo     %WHT%%%l%RST%
        set "found_ports=1"
    )
    
    if "!found_ports!"=="0" (
        echo     %YEL%No listening ports found%RST%
    )
    echo.
)

if %proc_count%==0 (
    echo %RED%No running processes found matching: %procname%%RST%
    endlocal
    exit /b 1
) else (
    echo %CYN%Summary: Found %proc_count% instance^(s^) of "%procname%"%RST%
    endlocal
    exit /b 0
)


:FindProcessByPort
setlocal EnableDelayedExpansion
set "port=%~1"

echo %CYN%Searching for processes listening on port %port%...%RST%
echo.

call :CreateTempFiles
if errorlevel 1 (
    echo %RED%Error: Cannot create temporary files%RST%
    exit /b 1
)

netstat -ano > "%tmp_netstat%" 2>nul
if errorlevel 1 (
    echo %RED%Error: Failed to get network information%RST%
    call :Cleanup
    exit /b 1
)

echo Proto  Local Address          Foreign Address        State           PID    Process
echo -----  -------------          ---------------        -----           ---    -------

set "found_connections=0"
for /f "usebackq tokens=1,2,3,4,5" %%a in (`findstr /r /c:"LISTENING" "%tmp_netstat%" ^| findstr /r /c:":%port% " ^| findstr /v /c:"["`) do (
    set "proto=%%a" & set "local=%%b" & set "foreign=%%c" & set "state=%%d" & set "pid=%%e"
    
    rem Get process name for this PID
    set "process_name=Unknown"
    for /f "usebackq skip=1 tokens=1 delims=," %%p in (`tasklist /fi "PID eq !pid!" /fo csv /nh 2^>nul`) do (
        set "process_name=%%~p"
        set "found_connections=1"
    )
    
    echo !proto!      !local!     !foreign!       !state!        !pid!      !process_name!
)

call :Cleanup

if "!found_connections!"=="0" (
    echo %YEL%No processes found listening on port %port%%RST%
    endlocal
    exit /b 0
) else (
    echo.
    echo %GRN%Found processes listening on port %port%%RST%
    endlocal
    exit /b 0
)

:Cleanup
if defined tmp_pids if exist "%tmp_pids%" del /f /q "%tmp_pids%" >nul 2>&1
if defined tmp_netstat if exist "%tmp_netstat%" del /f /q "%tmp_netstat%" >nul 2>&1
exit /b 0


:usage
echo.
echo %CYN%Network Process Port Finder v2.0%RST%
echo %WHT%================================%RST%
echo.
echo %YEL%Usage:%RST%
echo.
echo   %~nx0 ^<process_name^>    - Find listening ports for a process
echo   %~nx0 ^<port_number^>     - Find processes listening on a port
echo.
echo %YEL%Examples:%RST%
echo.
echo   %~nx0 chrome            - Find ports used by Chrome
echo   %~nx0 ollama            - Find ports used by everything
echo   %~nx0 80                - Find processes on port 80
echo   %~nx0 11434             - Find processes on port 443
echo.

echo.
echo %BLU%Note: Run as Administrator for complete process information%RST%
echo.
exit /b 1