Rework alias command to not to use external tools

bin/alias.bat

@@ -1,6 +1,12 @@
 @echo off
+
+set ALIASES=%CMDER_ROOT%\config\aliases
+
+if ["%*"] == [""] echo Use /? for help & echo. & goto :p_show
 if ["%1"] == ["/?"] goto:p_help
 if ["%1"] == ["/reload"] goto:p_reload
+:: /d flag for delete existing alias
+if ["%1"] == ["/d"] goto:p_del %*
 if ["%2"] == [""] echo Insufficient parameters. & goto:p_help
 ::validate alias
 setlocal
@@ -14,21 +20,36 @@ if not ["%_temp%"] == ["%_temp2%"] (
 	goto:eof
 )
 
-echo %* >> "%CMDER_ROOT%\config\aliases"
-doskey /macrofile="%CMDER_ROOT%\config\aliases"
-perl "%CMDER_ROOT%\scripts\clean_aliases.pl"
-echo Alias created
+:: replace already defined alias
+findstr /b /v /i "%_temp%=" "%ALIASES%" >> "%ALIASES%.tmp"
+echo %* >> "%ALIASES%.tmp" && type "%ALIASES%.tmp" > "%ALIASES%" & @del /f /q "%ALIASES%.tmp"
+doskey /macrofile="%ALIASES%"
 endlocal
 goto:eof
 
+:p_del
+findstr /b /v /i "%2=" "%ALIASES%" >> "%ALIASES%.tmp"
+type "%ALIASES%".tmp > "%ALIASES%" & @del /f /q "%ALIASES%.tmp"
+doskey /macrofile=%ALIASES%
+goto:eof
+
 :p_reload
-doskey /macrofile="%CMDER_ROOT%\config\aliases"
+doskey /macrofile="%ALIASES%"
 echo Aliases reloaded
 goto:eof
 
+:p_show
+type "%ALIASES%" || echo No aliases found at "%ALIASES%"
+goto :eof
+
 :p_help
 echo.Usage:
-echo.	alias name=full command
+echo.	alias [/reload] [/d] [name=full command]
+echo.     /reload  Reload the aliases file
+echo.     /d       Delete an alias (must be followed by the alias name)
+echo.
+echo.	If alias is called with any parameters, it will display the list of existing aliases.
+echo.	In the command, you can use the following notations:
 echo.	$* allows the alias to assume all the parameters of the supplied command.
 echo.	$1-$9 Allows you to seperate parameter by number, much like %%1 in batch.
 echo.	$T is the command seperator, allowing you to string several commands together into one alias.

config/aliases

@@ -4,3 +4,4 @@ ls=ls --color $*
 pwd=cd
 clear=cls
 history=cat %CMDER_ROOT%\config\.history
+unalias=alias /d $1