35} How can I substitute the second field on each line of my file?
Below is a simple demonstration substituting the second field with
"ab" on all the lines. Note the formulation of the for tokens, so
that all the fields will be covered.
@echo off
echo "123","45","678","901","234"> myfile.txt
echo "234","56","789","012","345">>myfile.txt
@echo off & setlocal enableextensions
for /f "tokens=
1,3,* delims=," %%q in ('type myfile.txt') do (
echo %%q,"ab",%%r,%%s>>outfile.txt)
type outfile.txt
endlocal & goto :EOF
The output will be
F:\CMD>d:cmdfaq
"123","ab","678","901","234"
"234","ab","789","012","345"
Note that the method will work even if the format of the lines were
"123" , "45" , "678" , "901" , "234"
For removing the quotes (if need be) and extracting separately the
contents of each field, see
the
previous item.
With
GnuWin32 gawk (let's call it unxgawk)
unxgawk -F, "{printf \"%%s,
\042ab
\042,%%s,%%s,%%s\n\",$1,$3,$4,$5}" "myfile.txt"
The output will again be
F:\CMD>d:cmdfaq
"123","ab","678","901","234"
"234","ab","789","012","345"
The solution assumes that all the lines contain the same number of
fields. - The
\042 is octal for the "
quote character.
The original task can also be solved with a Visual Basic Script (VBScript)
aided command line script. It is much more complicated and thus perhaps
not practical. However, the code is instructive and allows for flexibility.
@echo off & setlocal enableextensions
::
:: Build a test file
set testfile_=C:\_M\testfile.txt
> "%testfile_%" echo "123","45","678","901","234"
>>"%testfile_%" echo "999"
>>"%testfile_%" echo "888","777"
>>"%testfile_%" echo.
>>"%testfile_%" echo "234","56","789","012","345"
::
:: Build a Visual Basic Script
set skip=
set vbs_=%temp%\tmp$$$.vbs
>"%vbs_%" findstr "'%skip%VBS" "%~f0"
::
:: Run it with Microsoft Windows Script Host Version 5.6
<"%testfile_%" cscript //nologo "%vbs_%"
::
:: Clean up
for %%f in ("%vbs_%" "%testfile_%") do if exist %%f del %%f
endlocal & goto :EOF
'
'............................................
' The Visual Basic Script
'
TargetCol = 2 'VBS
TargetCol = TargetCol - 1 'VBS
Do While Not WScript.StdIn.AtEndOfStream 'VBS
LineStr = WScript.StdIn.ReadLine 'VBS
LineArray = Split(LineStr, ",", -1, vbTextCompare) 'VBS
LastI = UBound(LineArray) 'VBS
For i = 0 to LastI-1 'VBS
If i = TargetCol Then 'VBS
WScript.StdOut.Write Chr(34) + "ab" + Chr(34) 'VBS
If LastI > TargetCol Then WScript.StdOut.Write "," 'VBS
Else 'VBS
WScript.StdOut.Write LineArray(i) + "," 'VBS
End If 'VBS
Next 'VBS
If LastI > -1 Then 'VBS
If LastI = TargetCol Then 'VBS
WScript.StdOut.WriteLine Chr(34) + "ab" + Chr(34) 'VBS
Else 'VBS
WScript.StdOut.WriteLine LineArray(LastI) 'VBS
End If 'VBS
Else 'VBS
WScript.StdOut.WriteLine 'VBS
End If 'VBS
Loop 'VBS
The output will be
F:\CMD>d:cmdfaq
"123","ab","678","901","234"
"999"
"888","ab"
"234","ab","789","012","345"
Assorted NT/2000/XP/.. CMD.EXE Script Tricks
