From c39c4bb63becdee402771bae51046fdda674a149 Mon Sep 17 00:00:00 2001
From: CSRG <csrg@ucbvax.Berkeley.EDU>
Date: Sat, 16 Apr 1983 02:27:01 -0800
Subject: [PATCH] BSD 4_2 development Work on file
 usr/src/new/new/notes/src/pipeopen.c

Synthesized-from: CSRG/cd1/4.2
---
 usr/src/new/new/notes/src/pipeopen.c | 90 ++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 usr/src/new/new/notes/src/pipeopen.c

diff --git a/usr/src/new/new/notes/src/pipeopen.c b/usr/src/new/new/notes/src/pipeopen.c
new file mode 100644
index 0000000000..09f3b35358
--- /dev/null
+++ b/usr/src/new/new/notes/src/pipeopen.c
@@ -0,0 +1,90 @@
+/*
+ * pipeopen, pipeclose
+ * kludged from popen.c for notes
+ *
+ * Lou Salkind, NYU
+ */
+
+#include "parms.h"
+#include "structs.h"
+#include <stdio.h>
+#include <signal.h>
+#define	tst(a,b)	(*mode == 'r'? (b) : (a))
+#define	RDR	0
+#define	WTR	1
+static	int	p_pid;
+static	FILE	*fptr;
+extern	char	*myshell;
+static	int (*hstat)(), (*istat)(), (*qstat)();
+#ifdef	SIGTSTP
+static	int (*tstat)();
+#endif
+static	int brokpipe();
+
+FILE *
+pipeopen(cmd,mode)
+char	*cmd;
+char	*mode;
+{
+	int p[2];
+	register myside, hisside;
+
+	if(pipe(p) < 0)
+		return NULL;
+	myside = tst(p[WTR], p[RDR]);
+	hisside = tst(p[RDR], p[WTR]);
+	ttystop();
+	if((p_pid = fork()) == 0) {
+		close(myside);
+		dup2(hisside, tst(0, 1));
+		close(hisside);
+		setuid(globuid);
+		umask(msk);
+		uncatchem();
+		execl(myshell, "sh", "-c", cmd, 0);
+		_exit(1);
+	}
+	if(p_pid == -1) {
+		ttystrt();
+		return NULL;
+	}
+	istat = signal(SIGINT, SIG_IGN);
+	qstat = signal(SIGQUIT, SIG_IGN);
+	hstat = signal(SIGHUP, SIG_IGN);
+#ifdef	SIGTSTP
+	tstat = signal(SIGTSTP, SIG_DFL);
+#endif
+	signal(SIGPIPE, brokpipe);
+	close(hisside);
+	fptr = fdopen(myside, mode);
+	return(fptr);
+}
+
+pipeclose()
+{
+	register r;
+	int status;
+
+	fclose(fptr);
+	while((r = wait(&status)) != p_pid && r != -1)
+		;
+	if(r == -1)
+		status = -1;
+	ttystrt();
+	signal(SIGINT, istat);
+	signal(SIGQUIT, qstat);
+	signal(SIGHUP, hstat);
+#ifdef	SIGTSTP
+	signal(SIGTSTP, tstat);
+#endif
+	signal(SIGPIPE, SIG_DFL);
+	return(status);
+}
+
+static
+brokpipe()
+{
+	pipeclose();
+	wfchar();
+	longjmp(jenv, 1);
+}
-- 
2.20.1