From 7b0514fa023c068ab89e16a82b5d772605e5129d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dag-Erling=20Sm=C3=B8rgrav?= <des@FreeBSD.org>
Date: Tue, 18 Oct 2011 08:18:26 +0000
Subject: [PATCH] Simplify df(1) by factoring out most of the common code:

 - In the argc == 0 case, just populate the mount list as before, but
   do not calculate widths, update totals or print anything.

 - In the argv > 0 case, collect information about the requested file
   systems and store it in the mount list, but do not calculate
   widths, update totals or print anything.

 - In either case, once all the information has been collected,
   iterate once through the mount list to calculate widths and totals,
   then once more to print everything.

This also fixes two bugs: firstly, column widths were not calculated
correctly if more than one file system was specified on the command
line; and secondly, file systems with MNT_IGNORE were included in the
totals even if -a was not specified.

Noticed by:	Paul Schenkeveld
MFC after:	3 weeks
---
 bin/df/df.c | 55 +++++++++++++++++++++++++++--------------------------
 1 file changed, 28 insertions(+), 27 deletions(-)

diff --git a/bin/df/df.c b/bin/df/df.c
index 73f6acd75dfb..f865b8f1eeee 100644
--- a/bin/df/df.c
+++ b/bin/df/df.c
@@ -107,7 +107,7 @@ main(int argc, char *argv[])
 	const char *fstype;
 	char *mntpath, *mntpt;
 	const char **vfslist;
-	size_t i, mntsize;
+	int i, mntsize;
 	int ch, rv;
 
 	fstype = "ufs";
@@ -187,30 +187,21 @@ main(int argc, char *argv[])
 	argc -= optind;
 	argv += optind;
 
-	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
-	bzero(&maxwidths, sizeof(maxwidths));
-	for (i = 0; i < mntsize; i++)
-		update_maxwidths(&maxwidths, &mntbuf[i]);
-
 	rv = 0;
 	if (!*argv) {
+		/* everything (modulo -t) */
+		mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
 		mntsize = regetmntinfo(&mntbuf, mntsize, vfslist);
-		bzero(&maxwidths, sizeof(maxwidths));
-		for (i = 0; i < mntsize; i++) {
-			if (cflag)
-				addstat(&totalbuf, &mntbuf[i]);
-			update_maxwidths(&maxwidths, &mntbuf[i]);
-		}
-		if (cflag)
-			update_maxwidths(&maxwidths, &totalbuf);
-		for (i = 0; i < mntsize; i++)
-			if (aflag || (mntbuf[i].f_flags & MNT_IGNORE) == 0)
-				prtstat(&mntbuf[i], &maxwidths);
-		if (cflag)
-			prtstat(&totalbuf, &maxwidths);
-		exit(rv);
+	} else {
+		/* just the filesystems specified on the command line */
+		mntbuf = malloc(argc * sizeof(*mntbuf));
+		if (mntbuf == 0)
+			err(1, "malloc()");
+		mntsize = 0;
+		/* continued in for loop below */
 	}
 
+	/* iterate through specified filesystems */
 	for (; *argv; argv++) {
 		if (stat(*argv, &stbuf) < 0) {
 			if ((mntpt = getmntpt(*argv)) == 0) {
@@ -279,14 +270,24 @@ main(int argc, char *argv[])
 			continue;
 		}
 
-		if (argc == 1) {
-			bzero(&maxwidths, sizeof(maxwidths));
-			update_maxwidths(&maxwidths, &statfsbuf);
-		}
-		prtstat(&statfsbuf, &maxwidths);
-		if (cflag)
-			addstat(&totalbuf, &statfsbuf);
+		/* the user asked for it, so ignore the ignore flag */
+		statfsbuf.f_flags &= ~MNT_IGNORE;
+
+		/* add to list */
+		mntbuf[mntsize++] = statfsbuf;
 	}
+
+	bzero(&maxwidths, sizeof(maxwidths));
+	for (i = 0; i < mntsize; i++) {
+		if (aflag || (mntbuf[i].f_flags & MNT_IGNORE) == 0) {
+			update_maxwidths(&maxwidths, &mntbuf[i]);
+			if (cflag)
+				addstat(&totalbuf, &mntbuf[i]);
+		}
+	}
+	for (i = 0; i < mntsize; i++)
+		if (aflag || (mntbuf[i].f_flags & MNT_IGNORE) == 0)
+			prtstat(&mntbuf[i], &maxwidths);
 	if (cflag)
 		prtstat(&totalbuf, &maxwidths);
 	return (rv);