As @drruruu asked in this question :
> Is this possible **without** a temp file?
Yes, it's possible without a temp file. By sending ERRORLEVEL to STDOUT in the IN clause and parse it in the LOOP clause. **And it could be done with delayed expansion too**.
For convenience, here is an example. It's somewhat a FINDSTR wrapper that search for a string in the batch itself. It covers all the common cases where you need to know what was going wrong, where and why :
- Error in the DO () clause (aka the loop) and get the corresponding exit code
- Error in the IN () clause and get the corresponding exit code
- Error directly at the FOR clause (wrong syntax, bad delimiters, etc.)
The following script simulates theses situations with FINDSTR and flags as parameters :
- The first parameter is the string to search.
- The second parameter is a 0/1 flag to simulate an error not related to FINDSTR in the loop.
- The third parameter is a way to simulate an error on the FOR clause itself (not on IN nor LOOP)
- The fourth parameter is a way to test a FINDSTR which exit 255 when the file to search does not exist. Sadly, FINDSTR exit with 1 when it can't find a string in the file/files, but also exit with 1 when it can't find any files.. With the fourth parameter, we simulate a situation where FINDSTR exit with 255 when it can't find the file.
``` lang-batch
@echo off
SETLOCAL ENABLEEXTENSIONS
IF ERRORLEVEL 1 (
ECHO Can't use extensions
EXIT /B 1
)
SETLOCAL ENABLEDELAYEDEXPANSION
IF ERRORLEVEL 1 (
ECHO Can't use delayed expansion
EXIT /B 1
)
REM The string to search
SET "LOCALV_STRING=%1"
REM The file to search. Myself.
SET "LOCALV_THIS=%0"
REM Store the exit code for the LOOP
SET "LOCALV_ERR="
REM Store the exit code for the IN
SET "LOCALV_RET="
REM Flag to stop parsing output for error simulation
SET "LOCALV_END="
REM To get the exit code of the IN clause, we get it through expansion with a second FOR loop using the well known CALL expansion and send it on STDOUT in the form "__<code>"
FOR /F "%~3tokens=*" %%M IN ('FINDSTR "!LOCALV_STRING!" "!LOCALV_THIS%~4!" ^
^& FOR /F %%A IN ^("ERRORLEVEL"^) DO @CALL ECHO __%%%%A%%') DO (
SET "LOCALV_TMP=%%~M"
REM Simulate that something goes wrong with FINDSTR I/O
IF NOT EXIST "!LOCALV_THIS!%~4" (
SET "LOCALV_RET=255"
SET LOCALV_END=1
)
IF "!LOCALV_END!" == "" (
REM SImulate a problem in the loop
IF "%2" == "1" (
(CMD /C EXIT /B 127)
SET LOCALV_END=1
) ELSE (
IF NOT "!LOCALV_TMP:~0,2!" == "__" ECHO Found: !LOCALV_TMP!
)
)
IF "!LOCALV_TMP:~0,2!!LOCALV_RET!" == "__" SET "LOCALV_RET=!LOCALV_TMP:__=!"
)
SET "LOCALV_ERR=!ERRORLEVEL!"
REM LOCALV_ERR get the exit code from the last iteration of the for loop
REM LOCALV_RET get the exit code from the IN command of the for loop
REM Sadly, FINDSTR exit with 1 if it did not find the string, but also with 1 if it could not found the file. To simulate a proper handling of exit code for
REM abnormal hardware/software situation, %2 is used to force a 255 exit code
REM If LOCALV_RET is not defined, this means the FOR...ECHO__.. wasn't executed, therefore there is a pb with the FOR LOOP
IF "!LOCALV_RET!" == "" (
ECHO Something went wrong with FOR...
EXIT /B 1
)
REM If LOCALV_RET is defined, this means the FOR...ECHO__.. was executed and the last loop operation has parsed the FINDSTR exit code, LOCALV_RET get its exit code
REM If LOCALV_RET is defined but LOCALV_ERR is not "0", something went wrong in the loop (I/O error, out of memory, wathever you could think), the problem is not FINDSTR
IF NOT "!LOCALV_ERR!" == "0" (
ECHO Error in the loop while searching "!LOCALV_STRING!" in "!LOCALV_THIS!", exit code !LOCALV_RET!. Loop exit code : !LOCALV_ERR!.
EXIT /B 4
)
REM If LOCALV_RET is "0", FINDSTR got matching strings in the file, if "1", FINDSTR don't find any matching string, if anything else, FINDSTR got a problem like failed I/O.
REM If LOCALV_RET is "0" and LOCALV_ERR is "0", everything is ok.
IF "!LOCALV_RET!" == "0" (
ECHO Success.
EXIT /B 0
)
REM If LOCALV_RET is "1" and LOCALV_ERR is "0", FINDSTR failed to find the string in the file "or" failed to find file, for the latter we simulate that FINDSTR exit with 255 .
IF "!LOCALV_RET!" == "1" (
ECHO FINDSTR failed to find "!LOCALV_STRING!" in "!LOCALV_THIS!", exit code !LOCALV_RET!. Loop exit code : !LOCALV_ERR!.
EXIT /B 2
)
REM If LOCALV_RET isn't "0" nor "1" and LOCALV_ERR is "0", FINDSTR failed to do the job and LOCALV_RET got the exit code.
ECHO FINDSTR: Houst^W OP, we've got a problem here while searching "!LOCALV_STRING!" in "!LOCALV_THIS!", exit code !LOCALV_RET!. Loop exit code : !LOCALV_ERR!.
EXIT /B 3
```
Script output :
1) Normal operation, no error simulation.
```
PROMPT>.\for.bat FOR 0 "" ""
Found: FOR /F "%~3tokens=*" %%M IN ('FINDSTR "FOR" ""
Found: ^& FOR /F %%A IN ^("ERRORLEVEL"^) DO @CALL ECHO __%%%%A%%') DO (
Found: REM If LOCALV_RET is not defined, this means the FOR...ECHO__.. wasn't executed, therefore there is a pb with the FOR LOOP
Found: ECHO Something went wrong with FOR...
Found: REM If LOCALV_RET is defined, this means the FOR...ECHO__.. was executed and the last loop operation has parsed the FINDSTR exit code, LOCALV_RET get its exit code
Success.
```
2) Normal operation, no error simulation, with a string that FINDSTR can't find in the file.
```
PROMPT>.\for.bat ZZZ 0 "" ""
FINDSTR failed to find "ZZZ" in ".\for.bat", exit code 1. Loop exit code : 0.
```
3) Simulate an error in the LOOP clause, not related to FINDSTR.
```
PROMPT>.\for.bat FOR 1 "" ""
Error in the loop while searching "FOR" in ".\for.bat", exit code 0. Loop exit code : 127.
```
4) Simulate an error in the FOR clause at start with an unknow "delimstoken" option.
```
PROMPT>.\for.bat FOR 0 "delims" ""
delimstokens=*" was unexpected.
Something went wrong with FOR...
```
5) Simulate FINDSTR exiting 255 if it can't find the file.
```
PROMPT>.\for.bat FOR 1 "" "ERR"
FINDSTR : Can't open
FINDSTR: HoustW OP, we've got a problem here while searching "FOR" in ".\for.bat", exit code 255. Loop exit code : 0.
```
]
