How to get records right arranged in windows batch? - batch-file

Question

I have file s_result.txt as:
AAA,BBB,CCC
DDD,EEE
FFF,GGG
HHH,III,JJJ
...
And I try to get the sf_result.txt like this:
AAA,BBB
AAA,CCC
DDD,EEE
FFF,GGG
HHH,III
HHH,JJJ
...
I used script as below:
REM Transfer s_result.txt to sf_result.txt
DEL sf_result.txt
Echo. 2>sf_result.txt
for /F "tokens=1,2,3 delims=," %%a in (s_result.txt) do (
If %%c EQU [] (
ECHO %%a,%%b>>sf_result.txt
) else (
ECHO %%a,%%b>>sf_result.txt
ECHO %%a,%%c>>sf_result.txt
)
)
I got this result.txt instead:
AAA,BBB
AAA,CCC
DDD,EEE
DDD,
FFF,GGG
FFF,
HHH,III
HHH,JJJ
...
How can I get the right result?
Thanks,

Answer 1

If you want to parse line-by-line, use for /F. If you want to tokenize word-by-word on a single line, use for without the /F. Also, in a basic for loop, Windows already tokenizes on unquoted commas with no need to specify a delimiter. (It also tokenizes on spaces, tabs, and semicolons.) With this in mind, the solution is actually pretty simple.
#echo off & setlocal
for /f "usebackq tokens=1* delims=," %%I in ("test.txt") do (
for %%x in (%%J) do (
echo(%%I,%%x
)
)
Output:
AAA,BBB
AAA,CCC
DDD,EEE
FFF,GGG
HHH,III
HHH,JJJ

Answer 2

There have already been great answers provided with some smart approaches.
However, I want to stick to the code you posted here.
The main problem is the line if %%c EQU [], because it compares the third token with the literal string []; the third token can be CCC, JJJ, or an empty string, according to your example, so the condition is never going to be fulfilled.
To correct that, you should write if "%%c"=="" instead.
You could further improve your script by doing a single redirection > to the output file rather than creating it in advance and appending multiple times; just put the entire for /F loop in between parentheses and redirect the whole block.
So here is the corrected and improved code:
rem Transfer s_result.txt to sf_result.txt
> "sf_result.txt" (
for /F "usebackq tokens=1-3 delims=," %%a in ("s_result.txt") do #(
if "%%c"=="" (
echo %%a,%%b
) else (
echo %%a,%%b
echo %%a,%%c
)
)
)
The # symbol prevents command echoes of the loop body to be written to the output file as well. If there is #echo off placed at the beginning of your script you do no longer need that symbol.
Of course this code cannot handle lines with more than three tokens correctly.

Answer 3

I do like rojos clever approach (+1).
To overcome the implications he mentions I think of a recursive approach.
:: Q:\Test\2018\06\28\SO_51073893.cmd
#echo off & setlocal
for /f "usebackq tokens=1-2* delims=," %%A in ("test.txt") do Call :Sub "%%A" "%%B" "%%C"
Goto :Eof
:Sub
Echo %~1,%~2
if "%~3" neq "" for /f "tokens=1* delims=," %%D in (%3) do Call :Sub %1 "%%D" "%%E"
With a slightly changed file test.txt I get this output:
> SO_51073893.cmd
AAA,B=B
AAA,C;C
DDD,EEE
FFF,GGG
HHH,I I
HHH,JJJ