Detect Stderr from FBC compiling

[lassar]

I am working on a program to automate compiling in Freebasic dos.

I need to detect when there is a error in fbc and abort the rest of the program.

Here is what I have so far.

Code: Select all

#lang "FBLITE"

Cmd$ = COMMAND$
SHELL "FBC " + Cmd$

PeriodPos% = Instr(Cmd$,".")
FileName$ = LEFT$(Cmd$,PeriodPos%-1)
ExeName$ = FileName$ + ".exe"


SHELL "exe2coff " + ExeName$
SHELL "copy C:\bin\pmodstub.exe .\"
SHELL "copy /b pmodstub.exe+" + FileName$ + " " + ExeName$

How do I detect when FBC has error?

[dkl]

Hi,

like many programs, fbc returns a non-zero exit code in case of an error. You can check the result of the shell() function to detect this.

Code: Select all

var result = shell("fbc -version")
select case result
case 0
	print "ok, it worked"
case -1
	print "command not found (or other shell() failure)"
case else
	print "command aborted with exit code " & result
end select

By the way, fbc prints error messages to stdout, not stderr (yea, that's rather non-standard).

If you want to capture the error messages, check out Open Pipe.

[MrSwiss]

Just a remark on "shelling" from a compiled program:

I've learned "the hard way" that it is usually the better approach, to call a shell script (depending on OS).
The main REASONS are:
- flexibility: can be changed any Time "without touching source code of APPLICATION", recompiling etc.
- script can return Standard Error Codes, or "defined by you" Codes (on exit of script).

Ex. WIN: called "errorlevel" in *.cmd/*.bat (*.cmd = recommended, 32bit Console!)
Ex. DOS: called "errorlevel" in *.bat (16bit Console)

[marcov]

Just a remark on "shelling" from a compiled program:

I've learned "the hard way" that it is usually the better approach, to call a shell script (depending on OS).
The main REASONS are:
- flexibility: can be changed any Time "without touching source code of APPLICATION", recompiling etc.
- script can return Standard Error Codes, or "defined by you" Codes (on exit of script).

Ex. WIN: called "errorlevel" in *.cmd/*.bat (*.cmd = recommended, 32bit Console!)
Ex. DOS: called "errorlevel" in *.bat (16bit Console)

OTOH, if you use something CreateProcessW based it will actually be unicode. Running over a shell (cmd.exe) is always in the ansi encoding, and it is hard if not impossible to get accents right that are not in your default encoding.

[MrSwiss]

OTOH, if you use something CreateProcessW based it will actually be unicode. Running over a shell (cmd.exe) is always in the ansi encoding, and it is hard if not impossible to get accents right that are not in your default encoding.

Don't understand what you're about ...
This Thread reads DOS = ASCII, not any accenting ("plain old English", *.bat, command.com).

[marcov]

OTOH, if you use something CreateProcessW based it will actually be unicode. Running over a shell (cmd.exe) is always in the ansi encoding, and it is hard if not impossible to get accents right that are not in your default encoding.

Don't understand what you're about ...
This Thread reads DOS = ASCII, not any accenting ("plain old English", *.bat, command.com).

Then I wonder why the .cmd extension was mentioned. That got me off in the wrong direction. To my best knowledge command.com doesn't do .cmd.

[MrSwiss]

Then I wonder why the .cmd extension was mentioned.

A) Clearly marked as Example, by Ex:
B) To show that it's still "the same" (errorlevel) in later OS's
C) Advice for using the "more Modern" Command Processor, if NOT on DOS ...

Maybe a good Example, to illustrate a "quick Shot", that went off, into the wrong Direction ...
BTW: I don't like the "quick Shot" Approach, many here seem to favour (check the Outcome).