Add:

 1. C-x h to mark whole buffer.
 2. M-| to pipe current region to external command.
From Sunil Nimmagadda.

Feedback from deraadt@ and myself. ok for man page amendments from jmc@

6 files changed, 252 insertions, 9 deletions

diff --git a/usr.bin/mg/README b/usr.bin/mg/README
index 7ca5573ab27..6db7d63b425 100644
--- a/usr.bin/mg/README
+++ b/usr.bin/mg/README
@@ -61,7 +61,9 @@ recognized as special cases.
 On systems with 16 bit integers, the kill buffer cannot exceed 32767
 bytes.
 
-
+Unlike GNU Emacs, Mg's minibuffer isn't multi-line aware and hence
+some commands like "shell-command-on-region" always pop up a buffer to
+display output irrespective of output's size.
 
 New implementation oddities:
 
diff --git a/usr.bin/mg/def.h b/usr.bin/mg/def.h
index dab446b461a..867f3b127ca 100644
--- a/usr.bin/mg/def.h
+++ b/usr.bin/mg/def.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: def.h,v 1.118 2011/12/10 14:09:48 lum Exp $	*/
+/*	$OpenBSD: def.h,v 1.119 2012/04/11 17:51:10 lum Exp $	*/
 
 /* This file is in the public domain. */
 
@@ -567,6 +567,8 @@ int		 prefixregion(int, int);
 int		 setprefix(int, int);
 int		 region_get_data(struct region *, char *, int);
 void		 region_put_data(const char *, int);
+int		 markbuffer(int, int);
+int		 piperegion(int, int);
 
 /* search.c X */
 int		 forwsearch(int, int);
diff --git a/usr.bin/mg/funmap.c b/usr.bin/mg/funmap.c
index a1c05f77352..3a1132b0fbb 100644
--- a/usr.bin/mg/funmap.c
+++ b/usr.bin/mg/funmap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: funmap.c,v 1.36 2012/03/14 13:56:35 lum Exp $	*/
+/*	$OpenBSD: funmap.c,v 1.37 2012/04/11 17:51:10 lum Exp $	*/
 
 /* This file is in the public domain */
 
@@ -113,6 +113,7 @@ static struct funmap functnames[] = {
 	{localbind, "local-set-key",},
 	{localunbind, "local-unset-key",},
 	{makebkfile, "make-backup-files",},
+	{markbuffer, "mark-whole-buffer",},
 	{do_meta, "meta-key-mode",},	/* better name, anyone? */
 	{negative_argument, "negative-argument",},
 	{newline, "newline",},
@@ -166,6 +167,7 @@ static struct funmap functnames[] = {
 	{setfillcol, "set-fill-column",},
 	{setmark, "set-mark-command",},
 	{setprefix, "set-prefix-string",},
+	{piperegion, "shell-command-on-region",},
 	{shrinkwind, "shrink-window",},
 #ifdef NOTAB
 	{space_to_tabstop, "space-to-tabstop",},
diff --git a/usr.bin/mg/keymap.c b/usr.bin/mg/keymap.c
index 2fde87e59e6..5bd97a920b2 100644
--- a/usr.bin/mg/keymap.c
+++ b/usr.bin/mg/keymap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: keymap.c,v 1.47 2012/03/14 13:56:35 lum Exp $	*/
+/*	$OpenBSD: keymap.c,v 1.48 2012/04/11 17:51:10 lum Exp $	*/
 
 /* This file is in the public domain. */
 
@@ -135,7 +135,7 @@ static PF cXcar[] = {
 #endif /* !NO_MACRO */
 	setfillcol,		/* f */
 	gotoline,		/* g */
-	rescan,			/* h */
+	markbuffer,		/* h */
 	fileinsert,		/* i */
 	rescan,			/* j */
 	killbuffer_cmd,		/* k */
@@ -257,7 +257,7 @@ static PF metal[] = {
 	rescan,			/* y */
 	rescan,			/* z */
 	gotobop,		/* { */
-	rescan,			/* | */
+	piperegion,		/* | */
 	gotoeop			/* } */
 };
 
diff --git a/usr.bin/mg/mg.1 b/usr.bin/mg/mg.1
index b1428a7e310..a2133b77445 100644
--- a/usr.bin/mg/mg.1
+++ b/usr.bin/mg/mg.1
@@ -1,7 +1,7 @@
-.\"	$OpenBSD: mg.1,v 1.58 2012/02/09 09:00:14 lum Exp $
+.\"	$OpenBSD: mg.1,v 1.59 2012/04/11 17:51:10 lum Exp $
 .\" This file is in the public domain.
 .\"
-.Dd $Mdocdate: February 9 2012 $
+.Dd $Mdocdate: April 11 2012 $
 .Dt MG 1
 .Os
 .Sh NAME
@@ -196,6 +196,8 @@ call-last-kbd-macro
 set-fill-column
 .It C-x g
 goto-line
+.It C-x h
+mark-whole-buffer
 .It C-x i
 insert-file
 .It C-x k
@@ -260,6 +262,8 @@ copy-region-as-kill
 execute-extended-command
 .It M-{
 backward-paragraph
+.It M-|
+shell-command-on-region
 .It M-}
 forward-paragraph
 .It M-~
@@ -572,6 +576,9 @@ Bind a key mapping in the local (topmost) mode.
 Unbind a key mapping in the local (topmost) mode.
 .It make-backup-files
 Toggle generation of backup files.
+.It mark-whole-buffer
+Marks whole buffer as a region by putting dot at the beginning and mark
+at the end of buffer.
 .It meta-key-mode
 When disabled, the meta key can be used to insert extended-ascii (8-bit)
 characters.
@@ -734,6 +741,8 @@ Used by auto-fill-mode.
 Sets the mark in the current window to the current dot location.
 .It set-prefix-string
 Sets the prefix string to be used by the 'prefix-region' command.
+.It shell-command-on-region
+Provide the text in region to the shell command as input.
 .It shrink-window
 Shrink current window by one line.
 The window immediately below is expanded to pick up the slack.
diff --git a/usr.bin/mg/region.c b/usr.bin/mg/region.c
index eba11a25486..baca932ca1f 100644
--- a/usr.bin/mg/region.c
+++ b/usr.bin/mg/region.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: region.c,v 1.29 2009/06/05 18:02:06 kjell Exp $	*/
+/*	$OpenBSD: region.c,v 1.30 2012/04/11 17:51:10 lum Exp $	*/
 
 /* This file is in the public domain. */
 
@@ -9,9 +9,25 @@
  * internal use.
  */
 
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <fcntl.h>
+#include <poll.h>
+#include <string.h>
+#include <unistd.h>
+
 #include "def.h"
 
+#define TIMEOUT 10000
+
+static char leftover[BUFSIZ];
+
 static	int	getregion(struct region *);
+static	int	iomux(int);
+static	int	pipeio(const char *);
+static	int	preadin(int, struct buffer *);
+static	void	pwriteout(int, char **, int *);
 static	int	setsize(struct region *, RSIZE);
 
 /*
@@ -367,3 +383,215 @@ region_put_data(const char *buf, int len)
 			linsert(1, buf[i]);
 	}
 }
+
+/*
+ * Mark whole buffer by first traversing to end-of-buffer
+ * and then to beginning-of-buffer. Mark, dot are implicitly
+ * set to eob, bob respectively during traversal.
+ */
+int
+markbuffer(int f, int n)
+{
+	if (gotoeob(f,n) == FALSE)
+		return (FALSE);
+	if (gotobob(f,n) == FALSE)
+		return (FALSE);
+	return (TRUE);
+}
+
+/*
+ * Pipe text from current region to external command.
+ */
+/*ARGSUSED */
+int
+piperegion(int f, int n)
+{
+	char *cmd, cmdbuf[NFILEN];
+
+	/* C-u M-| is not supported yet */
+	if (n > 1)
+		return (ABORT);
+
+	if (curwp->w_markp == NULL) {
+		ewprintf("The mark is not set now, so there is no region");
+		return (FALSE);
+	}
+	if ((cmd = eread("Shell command on region: ", cmdbuf, sizeof(cmdbuf),
+	    EFNEW | EFCR)) == NULL || (cmd[0] == '\0'))
+		return (ABORT);
+
+	return (pipeio(cmdbuf));
+}
+
+/*
+ * Create a socketpair, fork and execl cmd passed. STDIN, STDOUT
+ * and STDERR of child process are redirected to socket.
+ */
+int
+pipeio(const char* const cmd)
+{
+	int s[2];
+	char *shellp;
+
+	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, s) == -1) {
+		ewprintf("socketpair error");
+		return (FALSE);
+	}
+	switch(fork()) {
+	case -1:
+		ewprintf("Can't fork");
+		return (FALSE);
+	case 0:
+		/* Child process */
+		close(s[0]);
+		if (dup2(s[1], STDIN_FILENO) == -1)
+			_exit(1);
+		if (dup2(s[1], STDOUT_FILENO) == -1)
+			_exit(1);
+		if (dup2(s[1], STDERR_FILENO) == -1)
+			_exit(1);
+		if ((shellp = getenv("SHELL")) == NULL)
+			_exit(1);
+		execl(shellp, "sh", "-c", cmd, (char *)NULL);
+		_exit(1);
+	default:
+		/* Parent process */
+		close(s[1]);
+		return iomux(s[0]);
+	}
+	return (FALSE);
+}
+
+/*
+ * Multiplex read, write on socket fd passed. First get the region,
+ * find/create *Shell Command Output* buffer and clear it's contents.
+ * Poll on the fd for both read and write readiness.
+ */
+int
+iomux(int fd)
+{
+	struct region region;
+	struct buffer *bp;
+	struct pollfd pfd[1];
+	int nfds;
+	char *text, *textcopy;
+	
+	if (getregion(&region) != TRUE)
+		return (FALSE);
+	
+	if ((text = malloc(region.r_size + 1)) == NULL)
+		return (ABORT);
+	
+	region_get_data(&region, text, region.r_size);
+	textcopy = text;
+	fcntl(fd, F_SETFL, O_NONBLOCK);
+	
+	/* There is nothing to write if r_size is zero
+	 * but the cmd's output should be read so shutdown 
+	 * the socket for writing only.
+	 */
+	if (region.r_size == 0)
+		shutdown(fd, SHUT_WR);
+	
+	bp = bfind("*Shell Command Output*", TRUE);
+	bp->b_flag |= BFREADONLY;
+	if (bclear(bp) != TRUE)
+		return (FALSE);
+
+	pfd[0].fd = fd;
+	pfd[0].events = POLLIN | POLLOUT;
+	while ((nfds = poll(pfd, 1, TIMEOUT)) != -1 ||
+	    (pfd[0].revents & (POLLERR | POLLHUP | POLLNVAL))) {
+		if (pfd[0].revents & POLLOUT && region.r_size > 0)
+			pwriteout(fd, &textcopy, &region.r_size);	
+		else if (pfd[0].revents & POLLIN)
+			if (preadin(fd, bp) == FALSE)
+				break;
+	}
+	close(fd);
+	free(text);
+	/* In case if last line doesn't have a '\n' add the leftover 
+	 * characters to buffer.
+	 */
+	if (leftover[0] != '\0') {
+		addline(bp, leftover);
+		leftover[0] = '\0';
+	}
+	if (nfds == 0) {
+		ewprintf("poll timed out");
+		return (FALSE);
+	} else if (nfds == -1) {
+		ewprintf("poll error");
+		return (FALSE);
+	}
+	return (popbuftop(bp, WNONE));
+}
+
+/*
+ * Write some text from region to fd. Once done shutdown the 
+ * write end.
+ */
+void
+pwriteout(int fd, char **text, int *len)
+{
+	int w;
+
+	if (((w = send(fd, *text, *len, MSG_NOSIGNAL)) == -1)) {
+		switch(errno) {
+		case EPIPE:
+			*len = -1;
+			break;
+		case EAGAIN:
+			return;
+		}
+	} else
+		*len -= w;
+
+	*text += w;
+	if (*len <= 0)
+		shutdown(fd, SHUT_WR);		
+}
+
+/*
+ * Read some data from socket fd, break on '\n' and add
+ * to buffer. If couldn't break on newline hold leftover
+ * characters and append in next iteration.
+ */
+int
+preadin(int fd, struct buffer *bp)
+{
+	int len;
+	static int nooutput;
+	char buf[BUFSIZ], *p, *q;
+
+	if ((len = read(fd, buf, BUFSIZ - 1)) == 0) {
+		if (nooutput == 0)
+			addline(bp, "(Shell command succeeded with no output)");
+		nooutput = 0;
+		return (FALSE);
+	}
+	nooutput = 1;
+	buf[len] = '\0';
+	p = q = buf;
+	if (leftover[0] != '\0' && ((q = strchr(p, '\n')) != NULL)) {
+		*q++ = '\0';
+		if (strlcat(leftover, p, sizeof(leftover)) >=
+		    sizeof(leftover)) {
+			ewprintf("line too long");
+			return (FALSE);
+		}
+		addline(bp, leftover);
+		leftover[0] = '\0';
+		p = q;
+	}
+	while ((q = strchr(p, '\n')) != NULL) {
+		*q++ = '\0';
+		addline(bp, p);
+		p = q;
+	}
+	if (strlcpy(leftover, p, sizeof(leftover)) >= sizeof(leftover)) {
+		ewprintf("line too long");
+		return (FALSE);
+	}
+	return (TRUE);
+}