make cat an mksh builtin, for things like here documents

if any options are given, the external programme is invoked instead

check.t

@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.388 2010/08/24 15:47:44 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.389 2010/08/28 17:21:41 tg Exp $
 # $OpenBSD: bksl-nl.t,v 1.2 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: history.t,v 1.5 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: read.t,v 1.3 2003/03/10 03:48:16 david Exp $
@@ -25,7 +25,7 @@
 # http://www.research.att.com/~gsf/public/ifs.sh
 
 expected-stdout:
-	@(#)MIRBSD KSH R39 2010/08/24
+	@(#)MIRBSD KSH R39 2010/08/28
 description:
 	Check version of shell.
 stdin:

exec.c

@@ -22,7 +22,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.77 2010/08/28 15:48:18 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.78 2010/08/28 17:21:43 tg Exp $");
 
 #ifndef MKSH_DEFAULT_EXECSHELL
 #define MKSH_DEFAULT_EXECSHELL	"/bin/sh"
@@ -489,6 +489,21 @@ comexec(struct op *t, struct tbl *volatile tp, const char **ap,
 				subst_exstat = 0;
 				break;
 			}
+		} else if (tp->val.f == c_cat) {
+			/*
+			 * if we have any flags, do not use the builtin
+			 * in theory, we could allow -u, but that would
+			 * mean to use ksh_getopt here and possibly ad-
+			 * ded complexity and more code and isn't worth
+			 */
+			if (ap[1] && ap[1][0] == '-' && ap[1][1] != '\0' &&
+			    /* argument, begins with -, is not - or -- */
+			    (ap[1][1] != '-' || ap[1][2] != '\0'))
+				/* don't look for builtins or functions */
+				fcflags = FC_PATH;
+			else
+				/* go on, use the builtin */
+				break;
 		} else
 			break;
 		tp = findcom(ap[0], fcflags & (FC_BI|FC_FUNC));

funcs.c

@@ -25,7 +25,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.157 2010/08/24 14:42:01 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.158 2010/08/28 17:21:44 tg Exp $");
 
 #if HAVE_KILLPG
 /*
@@ -102,6 +102,7 @@ const struct builtin mkshbuiltins[] = {
 	{"+fg", c_fgbg},
 #endif
 	{"bind", c_bind},
+	{"cat", c_cat},
 #if HAVE_MKNOD
 	{"mknod", c_mknod},
 #endif
@@ -3427,3 +3428,77 @@ c_realpath(const char **wp)
 
 	return (rv);
 }
+
+int
+c_cat(const char **wp)
+{
+	int fd = STDIN_FILENO, rv = 0;
+	ssize_t n, w;
+	const char *fn = "<stdin>";
+	char *buf, *cp;
+#define MKSH_CAT_BUFSIZ 4096
+
+	/* XXX uses malloc instead of lalloc (for alignment/speed) */
+	if ((buf = malloc(MKSH_CAT_BUFSIZ)) == NULL) {
+		bi_errorf("cannot allocate %lu data bytes",
+		    (unsigned long)MKSH_CAT_BUFSIZ);
+		return (1);
+	}
+
+	++wp;		/* argv[0] */
+	if (wp[0] && wp[0][0] == '-' && wp[0][1] == '-' && wp[0][2] == '\0')
+		++wp;	/* "--" (options separator) */
+
+	do {
+		if (*wp) {
+			fn = *wp++;
+			if (fn[0] == '-' && fn[1] == '\0')
+				fd = STDIN_FILENO;
+			else if ((fd = open(fn, O_RDONLY)) < 0) {
+				rv = errno;
+				bi_errorf("%s: %s", fn, strerror(rv));
+				rv = 1;
+				continue;
+			}
+		}
+		while (1) {
+			n = blocking_read(fd, (cp = buf), MKSH_CAT_BUFSIZ);
+			if (n == -1) {
+				if (errno == EINTR)
+					/* interrupted, try again */
+					continue;
+				/* an error occured during reading */
+				rv = errno;
+				bi_errorf("%s: %s", fn, strerror(rv));
+				rv = 1;
+				break;
+			} else if (n == 0)
+				/* end of file reached */
+				break;
+			while (n) {
+				w = write(STDOUT_FILENO, cp, n);
+				if (w == -1) {
+					if (errno == EINTR)
+						/* interrupted, try again */
+						continue;
+					/* an error occured during writing */
+					rv = errno;
+					bi_errorf("%s: %s", "<stdout>",
+					    strerror(rv));
+					rv = 1;
+					if (fd != STDIN_FILENO)
+						close(fd);
+					goto out;
+				}
+				n -= w;
+				cp += w;
+			}
+		}
+		if (fd != STDIN_FILENO)
+			close(fd);
+	} while (*wp);
+
+ out:
+	free(buf);
+	return (rv);
+}

mksh.1

@@ -1,4 +1,4 @@
-.\" $MirOS: src/bin/mksh/mksh.1,v 1.235 2010/08/24 14:42:03 tg Exp $
+.\" $MirOS: src/bin/mksh/mksh.1,v 1.236 2010/08/28 17:21:44 tg Exp $
 .\" $OpenBSD: ksh.1,v 1.136 2010/07/15 20:04:35 schwarze Exp $
 .\"-
 .\" Copyright © 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
@@ -71,7 +71,7 @@
 .\" with -mandoc, it might implement .Mx itself, but we want to
 .\" use our own definition. And .Dd must come *first*, always.
 .\"
-.Dd $Mdocdate: August 24 2010 $
+.Dd $Mdocdate: August 28 2010 $
 .\"
 .\" Check which macro package we use
 .\"
@@ -2780,10 +2780,10 @@ Additional
 .Nm
 regular commands
 .Pp
-.Ic \&[ , chdir , bind , echo ,
-.Ic let , mknod , print , printf ,
-.Ic pwd , realpath , rename , test ,
-.Ic ulimit , whence
+.Ic \&[ , chdir , bind , cat ,
+.Ic echo , let , mknod , print ,
+.Ic printf , pwd , realpath , rename ,
+.Ic test , ulimit , whence
 .Pp
 In the future, the additional
 .Nm
@@ -2963,6 +2963,22 @@ Execute the built-in command
 .Ar command .
 .Pp
 .It Xo
+.Ic cat
+.Op Fl \-
+.Op Ar
+.Xc
+Read files sequentially, in command line order, and write them to
+standard output.
+If
+.Ar file
+is a single dash
+.Pq Sq -
+or absent, read from standard input.
+If any options are given, an external
+.Xr cat 1
+utility is invoked instead.
+.Pp
+.It Xo
 .Ic cd
 .Op Fl LP
 .Op Ar dir
@@ -5910,6 +5926,7 @@ Privileged shell profile.
 .El
 .Sh SEE ALSO
 .Xr awk 1 ,
+.Xr cat 1 ,
 .Xr ed 1 ,
 .Xr getopt 1 ,
 .Xr sed 1 ,

sh.h

@@ -150,9 +150,9 @@
 #endif
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.408 2010/08/28 16:47:10 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.409 2010/08/28 17:21:46 tg Exp $");
 #endif
-#define MKSH_VERSION "R39 2010/08/24"
+#define MKSH_VERSION "R39 2010/08/28"
 
 #ifndef MKSH_INCLUDES_ONLY
 
@@ -1472,6 +1472,7 @@ int c_mknod(const char **);
 #endif
 int c_realpath(const char **);
 int c_rename(const char **);
+int c_cat(const char **);
 /* histrap.c */
 void init_histvec(void);
 void hist_init(Source *);