Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!newstop!texsun!letni!ataritx!atari!apratt
From: apratt@atari.UUCP (Allan Pratt)
Newsgroups: comp.sys.atari.st
Subject: Re: saving GCC errors (includes source!)
Keywords: question, save GCC compile errors
Message-ID: <2784@atari.UUCP>
Date: 17 Dec 90 22:46:47 GMT
References: <18949@netcom.UUCP>
Organization: Atari Corp., Sunnyvale CA
Lines: 113

rcb@netcom.UUCP (Roy Bixler) writes:
>I am using GNU C inside of Gulam 1.04.05 ...
>re-direct the standard error output to a file..

Here's a program that does what you're after.  It compiles under MWC, GCC,
and Alcyon C.  It works best under Gulam because Gulam implements shell_p,
a way for a child of Gulam to say "here, Gulam, please execute this
command line for me."  It may not be the best 'c' you've seen, but it
works.

(Interesting note: the MWC executable is 3622+690+188=4500 bytes
text+data+BSS (almost all text; real small), the Alcyon C executable is
6834+1434+9124=17392 bytes (half is GEM binding BSS), and the GCC
executable is 19592+904+3812=24308 bytes (just big).  The GCC "system"
call from Bammi's library is by far the most complex; I don't know what
else makes it so much larger. I tried to use "minimal.h" for the GCC
version but it didn't work: system() must use something from main.c.)

============================== rd2.c ==============================
/*
 * perform a system() call, but first, redirect handle 2 to a file.
 * See the umsg string for usage.
 * Written by Allan Pratt of Atari Corp., Dec. 17, 1990 and placed 
 * in the public domain without any warranty, expressed or implied.
 * Your mileage may vary.
 */

#include <osbind.h>

void usage();

int
main(argc,argv)
int argc;
char *argv[];
{
	int oh2;
	int nh2;
	long err, akp_system();
	int i;
	char buf[1024];

	if (argc < 3) usage();

	oh2 = Fdup(2);
	nh2 = Fcreate(argv[1],0);
	Fforce(2,nh2);

	strcpy(buf,argv[2]);

	for (i=3; i<argc; i++) {
		strcat(buf," '");
		strcat(buf,argv[i]);
		strcat(buf,"'");
	}

	err = akp_system(buf);

	Fclose(nh2);
	Fforce(2,oh2);
	Pterm(err);
}

/*
 * system() call used below.  It checks for SHELL_P in the environment.
 * If it's there, the pointer at 0x4f6 is assumed to point to a routine
 * which will execute a command string.  If it's not, the library system()
 * is called.  AKP.
 */

long
akp_system(s)
char *s;
{
	char *ptr, *getenv();

	if (getenv("SHELL_P") != 0) {
		long oldssp = Super(0L);
		long (*shell_p)() = *(long (**)())0x4f6;
		Super(oldssp);

		return (*shell_p)(s);
	}
	else return system(s);
}

char *umsg[] = {
  "Usage: rd2 stderr_file cmd args ...",
  "",
  "Where: stderr_file is the file that stderr (handle 2) gets redirected to,",
  "cmd is the command you want to execute, and args are the arguments to that",
  "command.  You can redirect stdout from your shell, and the child's stdout",
  "will go there; don't use the same file as stderr_file, though.",
  "",
  "(This program will use shell_p a la Gulam if you setenv SHELL_P to",
  "anything, otherwise it relies on the \"system()\" call from the library",
  "you compiled with.)",
  (char *)0
};

void
usage()
{
	char **p = umsg;

	while (*p) {
		Fwrite(1,(long)strlen(*p),*p);
		Fwrite(1,2L,"\r\n");
		p++;
	}
	Pterm(-1);
}
========================= end of rd2.c =========================