Add a -t switch for masking output that's above or below certain thresholds.

This switch makes it a lot easier to locate problem areas when a process
is threatening to consume all of your disk space.

PR:		144192
Submitted by:	gk
MFC after:	3 weeks

2 files changed, 28 insertions, 3 deletions

diff --git a/usr.bin/du/du.1 b/usr.bin/du/du.1
index af2ff84..8aacd81 100644
--- a/usr.bin/du/du.1
+++ b/usr.bin/du/du.1
@@ -42,7 +42,7 @@
 .Nm
 .Op Fl A
 .Op Fl H | L | P
-.Op Fl a | s | d Ar depth
+.Op Fl a | s | d Ar depth | Fl t Ar threshold
 .Op Fl c
 .Op Fl l
 .Op Fl h | k | m | B Ar blocksize
@@ -107,6 +107,14 @@ This option exists solely for conformance with
 Display an entry for each specified file.
 (Equivalent to
 .Fl d Li 0 )
+.It Fl t Ar threshold
+Display only entries for which size exceeds
+.Ar threshold .
+If
+.Ar threshold
+is negative, display only entries for which size is less than the absolute
+value of
+.Ar threshold .
 .It Fl d Ar depth
 Display an entry for all files and directories
 .Ar depth
diff --git a/usr.bin/du/du.c b/usr.bin/du/du.c
index 63677f5..761a1ab 100644
--- a/usr.bin/du/du.c
+++ b/usr.bin/du/du.c
@@ -90,6 +90,7 @@ main(int argc, char *argv[])
 	FTS		*fts;
 	FTSENT		*p;
 	off_t		savednumber, curblocks;
+	off_t		threshold, threshold_sign;
 	int		ftsoptions;
 	int		listall;
 	int		depth;
@@ -106,12 +107,14 @@ main(int argc, char *argv[])
 	save = argv;
 	ftsoptions = 0;
 	savednumber = 0;
+	threshold = 0;
+	threshold_sign = 1;
 	cblocksize = DEV_BSIZE;
 	blocksize = 0;
 	depth = INT_MAX;
 	SLIST_INIT(&ignores);
 
-	while ((ch = getopt(argc, argv, "AB:HI:LPasd:chklmnrx")) != -1)
+	while ((ch = getopt(argc, argv, "AB:HI:LPasd:chklmnrt:x")) != -1)
 		switch (ch) {
 		case 'A':
 			Aflag = 1;
@@ -179,6 +182,14 @@ main(int argc, char *argv[])
 			break;
 		case 'r':		 /* Compatibility. */
 			break;
+		case 't' :
+			if (expand_number(optarg, &threshold) != 0 ||
+			    threshold == 0) {
+				warnx("invalid threshold: %s", optarg);
+				usage();
+			} else if (threshold < 0)
+				threshold_sign = -1;
+			break;
 		case 'x':
 			ftsoptions |= FTS_XDEV;
 			break;
@@ -248,6 +259,10 @@ main(int argc, char *argv[])
 		blocksize /= DEV_BSIZE;
 	}
 
+	if (threshold != 0)
+		threshold = howmany(threshold / DEV_BSIZE * cblocksize,
+		    blocksize);
+
 	rval = 0;
 
 	(void)signal(SIGINFO, siginfo);
@@ -271,7 +286,9 @@ main(int argc, char *argv[])
 			p->fts_parent->fts_bignum += p->fts_bignum +=
 			    curblocks;
 
-			if (p->fts_level <= depth) {
+			if (p->fts_level <= depth && threshold <=
+			    threshold_sign * howmany(p->fts_bignum *
+			    cblocksize, blocksize)) {
 				if (hflag) {
 					prthumanval(p->fts_bignum);
 					(void)printf("\t%s\n", p->fts_path);