> > If you try to execute a process that is non-executable (like for > > example a word doc), then on Windows an exception is raised and > > GetLastOSError returns 193. > > > > If you try this on (my) linux, no exception is raised and a > > non-functional childprocess is forked (you can see it with ps ax). > > > This is because it is not waited for.
Yeah, found that out myself after fiddling around just a little more. > > Shouldn't trying to execute a non-executable file raise some kind > > of exception (like it does in Windows)? > > You cannot do this reliably. Starting a new process in linux is a 2-step > algorithm: > 1 Fork a clone of the current process. > 2 Execute the program that you want executed. > If step 2 fails, then there is no way to return an error message to > the parent process except a run-error code (127, I believe). OK, I come from DOS, so my knowledge of "inside-linux" is alomost zero at this point, so I did not know this. This makes me wonder, howevr, how bash can tell me that I tried to execute a non-executable file? > > If you try to execute a non-executable file from the console and query > > for the exitcode that bash returns, it will return an exitcode of 126, > > meaning: "Command invoked cannot execute" (Permission problem or > > command is not an executable) > > (This errorcode is not known to the syserrormessage function b.t.w.) > > > No, because this is bash-specific. Well, learned 2 new things in 1 email ;-) > > > > 2. > > Why does the GTK 1 app crash? This might be a GTK bug and not fpc related. > > > I don't think it is fpc related. That would suck then, since I guess GTK1 is "dead" (in the sence that it is not maintained)? > > ... is > > there a reliable way of cheking that a file can be executed in the > > first place? I know I can check for the execute permission of the file > > in question, but that is not enough (on my system any file copied from > > my windows partition to linux will have the x permission set). > You can use the fpaccess() call with X_OK for this; But it is not a > bullet-proof guarantee. You must know for sure which file exactly > will be executed. In my case I do know what file is executed (at leat I think I do know, I supply the absolute path to the program), but checking for X_OK is not a foolproof guarantee (see my remarks above). > Well, you can try using fpaccess. I borrowed this from somewhere in the code for the IDE (I believe): function FileIsExecutable(const AFilename: string): boolean; begin Result:= BaseUnix.FpAccess(AFilename,BaseUnix.X_OK)=0; end; Thanks, for your input. Bart _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
