How do you loop through each line in a text file using a windows batch file

Question

I would like to know how to loop through each line in a text file using a Windows batch file and process each line of text in succession

User · Answer

In a Batch File you MUST use    instead of      Type help for   for  F  tokens 1 2 3    i in  myfile txt  do call  process   i   j   k goto thenextstep  process set VAR1  1 set VAR2  2 set VAR3  3 COMMANDS TO PROCESS INFORMATION goto  EOF   What this does  The  do call  process   i   j   k  at the end of the for command passes the information acquired in the for command from myfile txt to the  process   subroutine    When you re using the for command in a batch program  you need to use double   signs for the variables   The following lines pass those variables from the for command to the process  sub routine  and allow you to process this information   set VAR1  1  set VAR2  2  set VAR3  3   I have some pretty advanced uses of this exact setup that I would be willing to share if further examples are needed   Add in your EOL or Delims as needed of course

User · Answer

From the Windows command line reference   To parse a file  ignoring commented lines  type   for  F  eol   tokens 2 3  delims     i in  myfile txt  do  echo  i  j  k   This command parses each line in Myfile txt  ignoring lines that begin with a semicolon and passing the second and third token from each line to the FOR body  tokens are delimited by commas or spaces   The body of the FOR statement references  i to get the second token   j to get the third token  and  k to get all of the remaining tokens    If the file names that you supply contain spaces  use quotation marks around the text  for example   File Name    To use quotation marks  you must use usebackq  Otherwise  the quotation marks are interpreted as defining a literal string to parse   By the way  you can find the command-line help file on most Windows systems at     C  WINDOWS Help ntcmds chm

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The accepted anwser using cmd exe and   for  F  tokens     F in  file txt  do whatever   F        works only for  normal  files  It fails miserably with huge files   For big files  you may need to use Powershell and something like this    IO File   ReadLines  file txt     ForEach-Object   whatever          or if you have enough memory   foreach  line in  System IO File   ReadLines  file txt      whatever   line       This worked for me with a 250 MB file containing over 2 million lines  where the for  F     command got stuck after a few thousand lines   For the differences between foreach and ForEach-Object  see Getting to Know ForEach and ForEach-Object    credits  Read file line by line in PowerShell

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Modded examples here to list our Rails apps on Heroku - thanks   cmd  C  heroku list  gt  heroku apps txt  find  v     heroku apps txt   find  v   TXT    findstr  r  v  c       gt  heroku apps list txt for  F  tokens 1    i in  heroku apps list txt  do heroku run bundle show rails --app   i   Full code here

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If you have an NT-family Windows  one with cmd exe as the shell   try the FOR  F command

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I needed to process the entire line as a whole   Here is what I found to work  for  F  quot tokens   quot    A in  myfile txt  do  process    A  The tokens keyword with an asterisk     will pull all text for the entire line   If you don t put in the asterisk it will only pull the first word on the line   I assume it has to do with spaces  For Command on TechNet  If there are spaces in your file path  you need to use usebackq  For example  for  F  quot usebackq tokens   quot    A in   quot my file txt quot   do  process    A

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Or  you may exclude the options in quotes   FOR  F   i IN  myfile txt  DO ECHO   i

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Here s a bat file I wrote to execute all SQL scripts in a folder   REM                                                                    REM Runs all   sql scripts sorted by filename in the current folder  REM To use integrated auth change -U  lt user gt  -P  lt password gt  to -E REM                                                                     dir  B  O n   sql  gt  RunSqlScripts tmp for  F   A in  RunSqlScripts tmp  do osql -S  local  -d DEFAULT DATABASE NAME -U USERNAME GOES HERE -P PASSWORD GOES HERE -i   A del RunSqlScripts tmp

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To print all lines in text file from command line  with delayedExpansion   set input  quot path to file txt quot   for  f  quot tokens   delims   quot   i in   type  quot  input  quot     find  v  n  quot  quot    do   set a  i set a  a       echo  a  1    Works with leading whitespace  blank lines  whitespace lines  Tested on Win 10 CMD

User · Answer

MrKraus s answer is instructive  Further  let me add that if you want to load a file located in the same directory as the batch file  prefix the file name with   dp0  Here is an example   cd  d   dp0 for  F  tokens      A in  myfile txt  do  process    A   NB   If your file name or directory  e g  myfile txt in the above example  has a space  e g   my file txt  or  c  Program Files    use   for  F  tokens      A in   type  my file txt    do  process    A     with the type keyword calling the type program  which displays the contents of a text file  If you don t want to suffer the overhead of calling the type command you should change the directory to the text file s directory  Note that type is still required for file names with spaces   I hope this helps someone

User · Answer

Improving the first  FOR  F    answer  What I had to do was to call execute every script listed in MyList txt  so it worked for me   for  F  tokens     A in   MyList txt  do CALL  A ARG1   --OR  if you wish to do it over the multiple line    for  F  tokens     A in   MuList txt  do   ECHO Processing  A     CALL  A ARG1     Edit  The example given above is for executing FOR loop from command-prompt  from a batch-script  an extra   needs to be added  as shown below   ---START of MyScript bat---  echo off for  F  tokens      A in    MyList TXT  do       ECHO Processing   A         CALL   A ARG1     echo on  ---END of MyScript bat---

User · Answer

The accepted answer is good  but has two limitations  It drops empty lines and lines beginning with    To read lines of any content  you need the delayed expansion toggling technic      echo off SETLOCAL DisableDelayedExpansion FOR  F  usebackq delims     a in    findstr  n    text txt    do       set  var   a      SETLOCAL EnableDelayedExpansion     set  var  var           echo  var      ENDLOCAL     Findstr is used to prefix each line with the line number and a colon  so empty lines aren t empty anymore     DelayedExpansion needs to be disabled  when accessing the   a parameter  else exclamation marks   and carets   will be lost  as they have special meanings in that mode     But to remove the line number from the line  the delayed expansion needs to be enabled  set  var  var       removes all up to the first colon  using delims   would remove also all colons at the beginning of a line  not only the one from findstr   The endlocal disables the delayed expansion again for the next line   The only limitation is now the line length limit of  8191  but there seems no way to overcome this

[windows] How do you loop through each line in a text file using a windows batch file?

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