Add fixwhite(1).

This small utility can be used to `sanitize' the whitespace in source
code. It does the following things:

Global:
- Remove empty lines at the beginning and the end of a file.
- Merge successive empty lines into a single empty line.

Per-line:
- Remove trailing whitespace.
- Merge spaces preceeding tabs into the tabs.

It operated on stdin/stdout. This means that if you use vi(1), you can
just run :%!fixwhite to reorganize the file.

3 files changed, 220 insertions, 0 deletions

diff --git a/tools/tools/fixwhite/Makefile b/tools/tools/fixwhite/Makefile
new file mode 100644
index 0000000..dbaabc2
--- /dev/null
+++ b/tools/tools/fixwhite/Makefile
@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+PROG=	fixwhite
+BINDIR=	/usr/bin
+WARNS=	6
+
+.include <bsd.prog.mk>
diff --git a/tools/tools/fixwhite/fixwhite.1 b/tools/tools/fixwhite/fixwhite.1
new file mode 100644
index 0000000..852a390
--- /dev/null
+++ b/tools/tools/fixwhite/fixwhite.1
@@ -0,0 +1,46 @@
+.\" Copyright (c) 2012 Ed Schouten <ed@FreeBSD.org>
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd February 6, 2012
+.Dt FIXWHITE 1
+.Os
+.Sh NAME
+.Nm fixwhite
+.Nd remove unneeded whitespace from text files
+.Sh SYNOPSIS
+.Nm
+.Sh DESCRIPTION
+The
+.Nm
+utility removes unneeded whitespace from text passed to standard input
+and prints the result to standard output.
+.Pp
+It removes leading and trailing empty lines from the input, as well as
+trailing whitespace characters from ever line of text.
+Multiple successive empty lines are merged together.
+Also, spaces preceeding tabs will be merged into the tab character.
+.Sh AUTHORS
+.An Ed Schouten Aq ed@FreeBSD.org
diff --git a/tools/tools/fixwhite/fixwhite.c b/tools/tools/fixwhite/fixwhite.c
new file mode 100644
index 0000000..276ae2e
--- /dev/null
+++ b/tools/tools/fixwhite/fixwhite.c
@@ -0,0 +1,167 @@
+/*-
+ * Copyright (c) 2012 Ed Schouten <ed@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static char *queue = NULL;
+static size_t queuelen = 0, queuesize = 0;
+static off_t column = 0;
+
+static void
+savebyte(char c)
+{
+
+	if (queuelen >= queuesize) {
+		queuesize += 128;
+		queue = realloc(queue, queuesize);
+		if (queue == NULL) {
+			perror("malloc");
+			exit(1);
+		}
+	}
+	queue[queuelen++] = c;
+
+	switch (c) {
+	case '\n':
+		column = 0;
+		break;
+	case ' ':
+		column++;
+		break;
+	case '\t':
+		column = (column / 8 + 1) * 8;
+		break;
+	}
+}
+
+static bool
+peekbyte(size_t back, char c)
+{
+
+	return (queuelen >= back && queue[queuelen - back] == c);
+}
+
+static void
+savewhite(char c, bool leading)
+{
+	off_t ncolumn;
+
+	switch (c) {
+	case '\n':
+		if (leading) {
+			/* Remove empty lines before input. */
+			queuelen = 0;
+			column = 0;
+		} else {
+			/* Remove trailing whitespace. */
+			while (peekbyte(1, ' ') || peekbyte(1, '\t'))
+				queuelen--;
+			/* Remove redundant empty lines. */
+			if (peekbyte(2, '\n') && peekbyte(1, '\n'))
+				return;
+			savebyte('\n');
+		}
+		break;
+	case ' ':
+		savebyte(' ');
+		break;
+	case '\t':
+		/* Convert preceeding spaces to tabs. */
+		ncolumn = (column / 8 + 1) * 8;
+		while (peekbyte(1, ' ')) {
+			queuelen--;
+			column--;
+		}
+		while (column < ncolumn)
+			savebyte('\t');
+		break;
+	}
+}
+
+static void
+printwhite(void)
+{
+
+	if (fwrite(queue, 1, queuelen, stdout) != queuelen) {
+		perror("write");
+		exit(1);
+	}
+	queuelen = 0;
+}
+
+static char
+readchar(void)
+{
+	int c;
+
+	c = getchar();
+	if (c == EOF && ferror(stdin)) {
+		perror("read");
+		exit(1);
+	}
+	return (c);
+}
+
+static void
+writechar(char c)
+{
+
+	if (putchar(c) == EOF) {
+		perror("write");
+		exit(1);
+	}
+	/* XXX: Multi-byte characters. */
+	column++;
+}
+
+int
+main(void)
+{
+	int c;
+	bool leading = true;
+
+	while ((c = readchar()) != EOF) {
+		if (isspace(c))
+			/* Save whitespace. */
+			savewhite(c, leading);
+		else {
+			/* Reprint whitespace and print regular character. */
+			printwhite();
+			writechar(c);
+			leading = false;
+		}
+	}
+	/* Terminate non-empty files with a newline. */
+	if (!leading)
+		writechar('\n');
+	return (0);
+}