From 4542db4e40f68bafaa4586d89fce4567c2d2b71e Mon Sep 17 00:00:00 2001
From: Michael Forney <mforney@mforney.org>
Date: Sun, 1 Mar 2020 16:30:56 -0800
Subject: [PATCH] mknod: Add support for making FIFOs

---
 mknod.1 | 31 +++++++++++++++++++------------
 mknod.c | 19 ++++++++++++++++---
 2 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/mknod.1 b/mknod.1
index 180b9cd..2541107 100644
--- a/mknod.1
+++ b/mknod.1
@@ -8,25 +8,32 @@
 .Nm
 .Op Fl m Ar mode
 .Ar name
-.Ar type
+.Cm b Ns | Ns Cm c Ns | Ns Cm u
 .Ar major
 .Ar minor
+.Nm
+.Op Fl m Ar mode
+.Ar name
+.Cm p
 .Sh DESCRIPTION
 .Nm
-creates a special device file named
-.Ar name
-with major number
+creates a special file named
+.Ar name .
+.Pp
+The following special file types are supported:
+.Bl -tag -width Ds
+.It Cm b
+A block device.
+.It Cm c | u
+A character device.
+.It Cm p
+A named pipe.
+.El
+.Pp
+Block and character devices are created with major number
 .Ar major ,
 and minor number
 .Ar minor .
-.Ar type
-specifies what kind of special file will be created and must be one of:
-.Bl -tag -width Ds
-.It Ar u | c
-A character device.
-.It Ar b
-A block device.
-.El
 .Sh OPTIONS
 .Bl -tag -width Ds
 .It Fl m
diff --git a/mknod.c b/mknod.c
index b4f7e5d..a519ecb 100644
--- a/mknod.c
+++ b/mknod.c
@@ -16,7 +16,9 @@
 static void
 usage(void)
 {
-	eprintf("usage: %s [-m mode] name type major minor\n", argv0);
+	eprintf("usage: %s [-m mode] name b|c|u major minor\n"
+	        "       %s [-m mode] name p\n",
+	        argv0, argv0);
 }
 
 int
@@ -33,7 +35,7 @@ main(int argc, char *argv[])
 		usage();
 	} ARGEND;
 
-	if (argc != 4)
+	if (argc < 2)
 		usage();
 
 	if (strlen(argv[1]) != 1)
@@ -46,12 +48,23 @@ main(int argc, char *argv[])
 	case 'c':
 		mode |= S_IFCHR;
 		break;
+	case 'p':
+		mode |= S_IFIFO;
+		break;
 	default:
 	invalid:
 		eprintf("invalid type '%s'\n", argv[1]);
 	}
 
-	dev = makedev(estrtonum(argv[2], 0, LLONG_MAX), estrtonum(argv[3], 0, LLONG_MAX));
+	if (S_ISFIFO(mode)) {
+		if (argc != 2)
+			usage();
+		dev = 0;
+	} else {
+		if (argc != 4)
+			usage();
+		dev = makedev(estrtonum(argv[2], 0, LLONG_MAX), estrtonum(argv[3], 0, LLONG_MAX));
+	}
 
 	if (mknod(argv[0], mode, dev) == -1)
 		eprintf("mknod %s:", argv[0]);