How to set a variable inside a loop for F

Question

I made this code  dir  B  S  RepToRead   gt   FileName   for  F  tokens      a in   type  FileName    do       set z   a     echo  z      echo   a     echo   a is working fine but echo  z  returns  echo disabled    I need to set a  z  because I want to split the variable like  z  7   Any ideas

User · Answer

I struggeld for many hours on this  This is my loop to register command line vars  Example   Register bat  param1 value1  param2 value2  What is does  is loop all the commandline params  and that set the variable with the proper name to the value   After that  you can just use  set value  param1  set value2  param2   regardless the sequence the params are given   so called named parameters   Note the   lt     instead of the   lt      SETLOCAL ENABLEDELAYEDEXPANSION  FOR   P IN      DO       call  processParam   P    goto End   processParam   1 - param        echo  processparam    1      FOR  F  tokens 1 2 delims      G IN    1   DO            echo a b   G   H         set nameWithSlash   G         set name  nameWithSlash  1           echo n  name          set value   H         set  name   value            goto  eof   End

User · Answer

The following should work   setlocal EnableDelayedExpansion for  F  tokens      a in   type  FileName    do       set  z   a      echo  z      echo   a

User · Answer

set list   a1-2019 a3-2018 a4-2017 setlocal enabledelayedexpansion set backup  set bb1   for  d   d in   list   do      set td   d    set x  td     set y  td     set y  y  -4     if  y  gtr  bb1         set bb1  y       set backup  x          rem  backup will be 2019 echo  backup

User · Answer

You probably want SETLOCAL ENABLEDELAYEDEXPANSION  See https   devblogs microsoft com oldnewthing 20060823-00  p 29993 for details   Basically  Normal  variables  are expanded right aftercmd exe reads the command  In your case the  command  is the whole  for  F  tokens      a in   type  FileName    do       set z   a     echo  z      echo   a     loop  At that point z has no value yet  so echo  z  turns into echo  Then the loop is executed and z is set  but its value isn t used anymore   SETLOCAL ENABLEDELAYEDEXPANSION enables an additional syntax   variable   This also expands variables but it only does so right before each  sub- command is executed   SETLOCAL ENABLEDELAYEDEXPANSION for  F  tokens      a in   type  FileName    do       set z   a     echo  z      echo   a     This gives you the current value of z each time the echo runs

User · Answer

There are two methods to setting and using variables within for loops and parentheses scope    setlocal enabledelayedexpansion see setlocal    for help   This only works on XP 2000 or newer versions of Windows  then use  variable  instead of  variable  inside the loop    Create a batch function using batch goto labels  Label   Example   for  F  tokens      a in   type  FileName    do call  Foo   a goto End   Foo set z  1 echo  z  echo  1 goto  eof   End   Batch functions are very useful mechanism

User · Answer

I know this isn t what s asked but I benefited from this method  when trying to set a variable within a  loop   Uses an array  Alternative implementation option   SETLOCAL ENABLEDELAYEDEXPANSION       set Services 0  SERVICE1 set Services 1  SERVICE2 set Services 2  SERVICE3  set  i 0    ServicesLoop if defined Services  i         set SERVICE  Services  i         echo CurrentService   SERVICE       set  a  i  1      GOTO  ServicesLoop

User · Answer

Try this   setlocal EnableDelayedExpansion       for  F  tokens      a in   type  FileName    do       set z   a     echo  z      echo   a

User · Answer

To expand on the answer I came here to get a better understanding so I wrote this that can explain it and helped me too   It has the setlocal DisableDelayedExpansion in there so you can locally set this as you wish between the setlocal EnableDelayedExpansion and it    echo off title   nx0 for  f  tokens      A in   Some Thing   do     setlocal EnableDelayedExpansion   set z   A   echo  z         Echoing the assigned variable in setlocal scope    echo   A        Echoing the variable in local scope    setlocal DisableDelayedExpansion   echo  z          amp rem  z            Neither of these now work  which makes sense    echo  z          amp rem ECHO is off   Neither of these now work  which makes sense    echo   A        Echoing the variable in its local scope  will always work

User · Answer

Simple example of batch code using  var    var   and      In this example code  focus here is that we want to capture a start time using the built in variable TIME  using time because it always changes automatically    Code    echo off setlocal enabledelayedexpansion SET  SERVICES LIST MMS ARSM MMS2  SET START  TIME  SET  LAST SERVICE    for   A in   SERVICES LIST   do       SET START  TIME      CALL  SOME FUNCTION   A     SET  LAST SERVICE   A      ping -n 5 127 0 0 1  gt  NUL     SET OTHER  START      if  OTHER  EQU  START        echo  OTHER  is equal to  START  as expected       ELSE       echo NOTHING         ECHO Last service run was  LAST SERVICE      Function declared like this  SOME FUNCTION echo Running   1 EXIT  B 0   Comments on code    Use enabledelayedexpansion   The first three SET lines are typical uses of the SET command  use this most of the time   The next line is a for loop  must use   A for iteration  then   B if a loop inside it etc   You can not use long variable names   To access a changed variable such as the time variable  you must use    or set with     have enableddelayexpansion enabled    When looping in for loop each iteration is accessed as the   A variable  The code in the for loop is point out the various ways to set a variable  Looking at  SET OTHER  START    if you were to change to SET OTHER  START  you will see why    is needed   hint  you will see NOTHING  output  In short    is more likely needed inside of loops   var  in general     always a for loop    Further reading  Use the following links to determine why in more detail    Difference between  variable  and  variable  in batch file Variable usage in batch file

[batch-file] How to set a variable inside a loop for /F

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