diff-buffer-with-file

input gsoares@, Sunil Nimmagadda, jasper@
ok jasper@, benno@

4 files changed, 84 insertions, 5 deletions

diff --git a/usr.bin/mg/buffer.c b/usr.bin/mg/buffer.c
index 0b16af1f737..0b590ebbfd8 100644
--- a/usr.bin/mg/buffer.c
+++ b/usr.bin/mg/buffer.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: buffer.c,v 1.87 2012/11/06 18:04:10 florian Exp $	*/
+/*	$OpenBSD: buffer.c,v 1.88 2012/12/27 18:51:52 florian Exp $	*/
 
 /* This file is in the public domain. */
 
@@ -12,6 +12,10 @@
 #include <libgen.h>
 #include <stdarg.h>
 
+#ifndef DIFFTOOL
+#define DIFFTOOL "/usr/bin/diff"
+#endif /* !DIFFTOOL */
+
 static struct buffer  *makelist(void);
 static struct buffer *bnew(const char *);
 
@@ -920,3 +924,74 @@ dorevert(void)
 		return(setlineno(lineno));
 	return (FALSE);
 }
+
+/*
+ * Diff the current buffer to what is on disk.
+ */
+/*ARGSUSED */
+int
+diffbuffer(int f, int n)
+{
+	struct buffer	*bp;
+	struct line	*lp, *lpend;
+	size_t		 len;
+	int		 ret;
+	char		*text, *ttext;
+	char		* const argv[] =
+	    {DIFFTOOL, "-u", "-p", curbp->b_fname, "-", (char *)NULL};
+
+	len = 0;
+
+	/* C-u is not supported */
+	if (n > 1)
+		return (ABORT);
+
+	if (access(DIFFTOOL, X_OK) != 0) {
+		ewprintf("%s not found or not executable.", DIFFTOOL);
+		return (FALSE);
+	}
+
+	if (curbp->b_fname[0] == 0) {
+		ewprintf("Cannot diff buffer not associated with any files.");
+		return (FALSE);
+	}
+
+	lpend = curbp->b_headp;
+	for (lp = lforw(lpend); lp != lpend; lp = lforw(lp)) {
+		len+=llength(lp);
+		if (lforw(lp) != lpend)		/* no implied \n on last line */
+			len++;
+	}
+	if ((text = calloc(len + 1, sizeof(char))) == NULL) {
+		ewprintf("Cannot allocate memory.");
+		return (FALSE);
+	}
+	ttext = text;
+
+	for (lp = lforw(lpend); lp != lpend; lp = lforw(lp)) {
+		if (llength(lp) != 0) {
+			memcpy(ttext, ltext(lp), llength(lp));
+			ttext += llength(lp);
+		}
+		if (lforw(lp) != lpend)		/* no implied \n on last line */
+			*ttext++ = '\n';
+	}
+
+	bp = bfind("*Diff*", TRUE);
+	bp->b_flag |= BFREADONLY;
+	if (bclear(bp) != TRUE) {
+		free(text);
+		return (FALSE);
+	}
+
+	ret = pipeio(DIFFTOOL, argv, text, len, bp);
+
+	if (ret == TRUE) {
+		eerase();
+		if (lforw(bp->b_headp) == bp->b_headp)
+			addline(bp, "Diff finished (no differences).");
+	}
+
+	free(text);
+	return (ret);
+}
diff --git a/usr.bin/mg/def.h b/usr.bin/mg/def.h
index 9a6e82ce7d9..c3c8f6194bb 100644
--- a/usr.bin/mg/def.h
+++ b/usr.bin/mg/def.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: def.h,v 1.133 2012/12/27 18:49:59 florian Exp $	*/
+/*	$OpenBSD: def.h,v 1.134 2012/12/27 18:51:52 florian Exp $	*/
 
 /* This file is in the public domain. */
 
@@ -417,6 +417,7 @@ int		 getbufcwd(char *, size_t);
 int		 checkdirty(struct buffer *);
 int		 revertbuffer(int, int);
 int		 dorevert(void);
+int		 diffbuffer(int, int);
 
 /* display.c */
 int		vtresize(int, int, int);
diff --git a/usr.bin/mg/funmap.c b/usr.bin/mg/funmap.c
index 608ba5922b8..a675b6ec1fc 100644
--- a/usr.bin/mg/funmap.c
+++ b/usr.bin/mg/funmap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: funmap.c,v 1.44 2012/12/04 10:54:20 florian Exp $	*/
+/*	$OpenBSD: funmap.c,v 1.45 2012/12/27 18:51:52 florian Exp $	*/
 
 /* This file is in the public domain */
 
@@ -74,6 +74,7 @@ static struct funmap functnames[] = {
 	{delwind, "delete-window",},
 	{wallchart, "describe-bindings",},
 	{desckey, "describe-key-briefly",},
+	{diffbuffer, "diff-buffer-with-file",},
 	{digit_argument, "digit-argument",},
 	{lowerregion, "downcase-region",},
 	{lowerword, "downcase-word",},
diff --git a/usr.bin/mg/mg.1 b/usr.bin/mg/mg.1
index 618cc3936ba..fffd26ed620 100644
--- a/usr.bin/mg/mg.1
+++ b/usr.bin/mg/mg.1
@@ -1,7 +1,7 @@
-.\"	$OpenBSD: mg.1,v 1.73 2012/12/04 10:54:20 florian Exp $
+.\"	$OpenBSD: mg.1,v 1.74 2012/12/27 18:51:52 florian Exp $
 .\" This file is in the public domain.
 .\"
-.Dd $Mdocdate: December 4 2012 $
+.Dd $Mdocdate: December 27 2012 $
 .Dt MG 1
 .Os
 .Sh NAME
@@ -495,6 +495,8 @@ the *help* buffer.
 .It describe-key-briefly
 Read a key from the keyboard, and look it up in the keymap.
 Display the name of the function currently bound to the key.
+.It diff-buffer-with-file
+View the differences between buffer and its associated file.
 .It digit-argument
 Process a numerical argument for keyboard-invoked functions.
 .It downcase-region