From: Ilya Zakharevich <ilya@math.berkeley.edu>
Date: Thu, 10 Jun 1999 04:05:22 +0000 (-0400)
Subject: Optimize 2>&1 in commands
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=603a98b057dc0594e88193eb408d3eea3f3e4908;p=p5sagit%2Fp5-mst-13.2.git

Optimize 2>&1 in commands

	Message-Id: <199906100805.EAA18216@monk.mps.ohio-state.edu>

p4raw-id: //depot/perl@3621
---

diff --git a/doio.c b/doio.c
index 39e2e9f..7c093ae 100644
--- a/doio.c
+++ b/doio.c
@@ -1126,6 +1126,20 @@ Perl_do_exec3(pTHX_ char *cmd, int fd, int do_report)
 		*s = '\0';
 		break;
 	    }
+	    /* handle the 2>&1 construct at the end */
+	    if (*s == '>' && s[1] == '&' && s[2] == '1'
+		&& s > cmd + 1 && s[-1] == '2' && isSPACE(s[-2])
+		&& (!s[3] || isSPACE(s[3])))
+	    {
+		char *t = s + 3;
+
+		while (*t && isSPACE(*t))
+		    ++t;
+		if (!*t && (dup2(1,2) != -1)) {
+		    s[-2] = '\0';
+		    break;
+		}
+	    }
 	  doshell:
 	    PerlProc_execl(PL_sh_path, "sh", "-c", cmd, (char*)0);
 	    return FALSE;