From: peter@ficc.uu.net (Peter da Silva)
Newsgroups: alt.sources
Subject: Patch for TCL for systems without dup2.
Message-ID: <O762Y24ggpc2@ficc.uu.net>
Date: 12 Mar 90 04:51:34 GMT

Archive-name: tcl/patch.1

Here's a patch for tcl for older System V systems without the dup2 system
call (or library routine). It's a bit overkillish, but makes the code a bit
nicer. Rather than emulate dup2, I switched back to the older method of
depending on fds being allocated in numerical order...

*** tclCmdAH.old
--- tclCmdAH.c
***************
*** 410,415 ****
--- 410,435 ----
   *----------------------------------------------------------------------
   */
  
+ static int setup_fds(fd0, fd1, fd2)
+ {
+ 	if(fd0 != -1) {
+ 		close(0);
+ 		if(dup(fd0) != 0)
+ 			return 0;
+ 	}
+ 	if(fd1 != -1) {
+ 		close(1);
+ 		if(dup(fd1) != 1)
+ 			return 0;
+ 	}
+ 	if(fd2 != -1) {
+ 		close(2);
+ 		if(dup(fd2) != 2)
+ 			return 0;
+ 	}
+ 	return 1;
+ }
+ 
  	/* ARGSUSED */
  int
  Tcl_ExecCmd(dummy, interp, argc, argv)
***************
*** 510,517 ****
      if (pid == 0) {
  	char errSpace[100];
  
! 	if (( (stdIn != -1) && (dup2(stdIn, 0) == -1) )
! 	   || (dup2(stdOut[1], 1) == -1) || (dup2(stdOut[1], 2) == -1)) {
  	    char *err;
  	    err = "forked process couldn't set up input/output";
  	    write(stdOut[1], err, strlen(err));
--- 530,536 ----
      if (pid == 0) {
  	char errSpace[100];
  
! 	if(!setup_fds(stdIn, stdOut[1], stdOut[1])) {
  	    char *err;
  	    err = "forked process couldn't set up input/output";
  	    write(stdOut[1], err, strlen(err));
-- 
 _--_|\  `-_-' Peter da Silva. +1 713 274 5180. <peter@ficc.uu.net>.
/      \  'U`
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