1 files changed, 91 insertions, 0 deletions
diff --git a/lib/libss/pager.c b/lib/libss/pager.c
new file mode 100644
index 0000000..b419725
--- /dev/null
+++ b/lib/libss/pager.c
@@ -0,0 +1,91 @@
+/*
+ * Pager: Routines to create a "more" running out of a particular file
+ * descriptor.
+ *
+ * Copyright 1987, 1988 by MIT Student Information Processing Board
+ *
+ * For copyright information, see copyright.h.
+ */
+
+#include "ss_internal.h"
+#include "copyright.h"
+#include <stdio.h>
+#include <sys/file.h>
+#include <signal.h>
+#include <unistd.h>
+
+static char MORE[] = "more";
+extern char *_ss_pager_name;
+extern char *getenv();
+extern int errno;
+
+/*
+ * this needs a *lot* of work....
+ *
+ * run in same process
+ * handle SIGINT sensibly
+ * allow finer control -- put-page-break-here
+ */
+void ss_page_stdin();
+
+#ifndef NO_FORK
+int ss_pager_create()
+{
+	int filedes[2];
+
+	if (pipe(filedes) != 0)
+		return(-1);
+
+	switch(fork()) {
+	case -1:
+		return(-1);
+	case 0:
+		/*
+		 * Child; dup read half to 0, close all but 0, 1, and 2
+		 */
+		if (dup2(filedes[0], 0) == -1)
+			exit(1);
+		ss_page_stdin();
+	default:
+		/*
+		 * Parent:  close "read" side of pipe, return
+		 * "write" side.
+		 */
+		(void) close(filedes[0]);
+		return(filedes[1]);
+	}
+}
+#else /* don't fork */
+int ss_pager_create()
+{
+    int fd;
+    fd = open("/dev/tty", O_WRONLY, 0);
+    return fd;
+}
+#endif
+
+void ss_page_stdin()
+{
+	int i;
+	for (i = 3; i < 32; i++)
+		(void) close(i);
+	(void) signal(SIGINT, SIG_DFL);
+	{
+		register int mask = sigblock(0);
+		mask &= ~sigmask(SIGINT);
+		sigsetmask(mask);
+	}
+	if (_ss_pager_name == (char *)NULL) {
+		if ((_ss_pager_name = getenv("PAGER")) == (char *)NULL)
+			_ss_pager_name = MORE;
+	}
+	(void) execlp(_ss_pager_name, _ss_pager_name, (char *) NULL);
+	{
+		/* minimal recovery if pager program isn't found */
+		char buf[80];
+		register int n;
+		while ((n = read(0, buf, 80)) > 0)
+			write(1, buf, n);
+	}
+	exit(errno);
+}