Is there an equivalent to 'cut -c' in Windows cmd.exe? - windows

Question

I have some files of fixed line size, fixed field size that I need to extract information from. Nornmally, I'd use Cygwin (cut et al), but that's not an option in this case due to (boneheaded) management policies I can't change. It has to be done using standard XP toolset included with Windows.
I need to extract the 10 characters at offset 7 and 4 characters at offset 22 (zero-based), and output them to a file but with a slight twist:
The first field may have a negative, positive, or no sign (at the start or end). The sign should be moved to the front, or removed totally if it's positive.
The second field should have leading and trailing spaces removed.
For example:
1 2 3 <- ignore (these lines not in file,)
0123456789012345678901234567890123456789 <- ignore ( here only for info.)
xxxxxxx 15.22-yyyyyABCDzzzzzzzzzzz...
xxxxxxx 122.00+yyyyy XX zzzzzzzzzzz...
xxxxxxx 9yyyyyYYY zzzzzzzzzzz...
should produce (< indicates end of line):
-15.22,ABCD<
122.00,XX<
9,YYY<

Answer 1

If you working with modern windows, you are not restricted to cmd.exe commands natively, you can use vbscript. If your policy is not to use vbscript either, then I guess you should sack your management :)
Set objFS=CreateObject("Scripting.FileSystemObject")
strFile = "c:\test\file"
Set objFile = objFS.OpenTextFile(strFile)
strFirstLine = objFile.ReadLine
Do Until objFile.AtEndOfStream
strLine= objFile.ReadLine
var1 = Mid(strLine,10) ' do substring from position 10 onwards
' var2 = Mid (strLine,<pos>,<length>) ' get next offset and save to var2
WScript.Echo var1 & var2 ' print them out.
Loop
Basically, to "cut" characters of a string, you use Mid() function. please look at the vbscript documentation to find out more.
Save the above as test.vbs and, on the command line, do
c:\test> cscript /nologo test.vbs > newfile
Of course, "substring" can also be done with pure cmd.exe but I will leave it to some others to guide you.
Update by Pax: Based on this answer, I came up with the following which will be a good start:
option explicit
dim objFs, objFile, strLine, value1, value2
if wscript.arguments.count < 1 then
wscript.echo "Usage: process <input-file>"
wscript.quit
end if
set objFs=createObject("Scripting.FileSystemObject")
set objFile = objFs.openTextFile(wscript.arguments.item(0))
do until objFile.atEndOfStream
strLine= objFile.readLine
value1 = trim(mid(strLine, 8, 10))
value2 = trim(mid(strLine, 23, 4))
if right(value1,1) = "-" then value1 = "-" & left(value1,len(value1)-1)
if right(value1,1) = "+" then value1 = left(value1,len(value1)-1)
if left(value1,1) = "+" then value1 = mid(value1,2)
wscript.echo value1 & "," & value2
loop
This matches all the requirements we had. We can make the offsets and lengths into command-line arguments later.
End update.

Answer 2

This site has some pointers on how to extract substrings in cmd.exe: http://www.dostips.com/DtTipsStringManipulation.php
That site suggests that you can use
%varname:~2,3%
to subscript a variable. This seems to fill your needs, except you now have to get each line into a variable.
Next you want to look at the ghastly for loop syntax and if and branching (you can goto :labels in batch).
This stuff is all rather ugly, but if you really have to go there...
Here is a page in SO on looping through files and doing stuff to them: How do you loop through each line in a text file using a windows batch file?

Answer 3

Here's a small script (needs to be in a BAT/CMD file) expanding on what Daren Thomas suggested:
#echo off
setlocal
set key=HKCU\Software\Microsoft\Windows\CurrentVersion\Ext\Stats\{D27CDB6E-AE6D-11CF-96B8-444553540000}\iexplore\AllowedDomains
echo.
echo Liste der fuer Flash im IE zugelassenen Domaenen:
echo =================================================
for /f "usebackq tokens=11 delims=\" %%l in (`call reg query "%key%" /s`) do echo. %%l
echo.
endlocal
The FOR loop is the central part. Note the use of command modifiers in double quotes. I specify tokens=11 because I'm only interested in the subkeys of AllowedDomains, which is at position 10.
Be sure to read the help in for /?. Daren is right when he says this stuff is all rather ugly. And it easily breaks down on modification. There's a lot of non-intuitive subtleties with cmd.exe script syntax.
By the way, the GUID is the COM class ID for the Shockwave Flash Add-on. It's been around since at least 2001 so might well continue to be relevant for the foreseeable future. The purpose of the script is to list the domains where Flash, which I prefer to block by default, has been allowed.