Index: usr.bin/top/commands.h
===================================================================
--- usr.bin/top/commands.h
+++ usr.bin/top/commands.h
@@ -46,6 +46,7 @@
 	CMD_order,
 	CMD_pid	,
 	CMD_toggletid,
+	CMD_filter,
 };
 
 struct command {
Index: usr.bin/top/commands.c
===================================================================
--- usr.bin/top/commands.c
+++ usr.bin/top/commands.c
@@ -56,6 +56,7 @@
 	{'C', "toggle the displaying of weighted CPU percentage", false, CMD_wcputog},
 	{'d', "change number of displays to show", false, CMD_displays},
 	{'e', "list errors generated by last \"kill\" or \"renice\" command", false, CMD_errors},
+	{'/', "filter by command (enter for all)", false, CMD_filter},
 	{'H', "toggle the displaying of threads", false, CMD_thrtog},
 	{'h', "show this help text", true, CMD_help},
 	{'?', NULL, true, CMD_help},
Index: usr.bin/top/machine.c
===================================================================
--- usr.bin/top/machine.c
+++ usr.bin/top/machine.c
@@ -224,6 +224,7 @@
 static int swapmode(int *retavail, int *retfree);
 static void update_layout(void);
 static int find_uid(uid_t needle, int *haystack);
+static int cmd_match(struct kinfo_proc *pp, const char *pattern);
 
 static int
 find_uid(uid_t needle, int *haystack)
@@ -730,6 +731,32 @@
 	return (get_io_stats(pp, &dummy, &dummy, &dummy, &dummy, &dummy));
 }
 
+static int
+cmd_match(struct kinfo_proc *pp, const char *pattern)
+{
+	char **argv;
+
+	/* matched with command name */
+	if (strcasestr(pp->ki_comm, pattern) != NULL)
+		return (1);
+
+	/* when displaying command arguments, check those too */
+	if (fmt_flags & FMT_SHOWARGS) {
+		argv = kvm_getargv(kd, pp, 0);
+
+		if (argv != NULL) {
+			while (*argv != NULL) {
+				/* found a match */
+				if (strcasestr(*argv, pattern) != NULL)
+					return (1);
+				argv++;
+			}
+		}
+	}
+	/* no match */
+	return (0);
+}
+
 static struct handle handle;
 
 void *
@@ -843,6 +870,10 @@
 
 		if (!sel->kidle && pp->ki_tdflags & TDF_IDLETD && sel->pid == -1)
 			/* skip kernel idle process */
+			continue;
+
+		if (sel->command != NULL && !cmd_match(pp, sel->command))
+			/* skip processes that don't match the command name */
 			continue;
 
 		PCTCPU(pp) = proc_calc_pctcpu(pp);
Index: usr.bin/top/top.h
===================================================================
--- usr.bin/top/top.h
+++ usr.bin/top/top.h
@@ -31,6 +31,7 @@
 
 extern enum displaymodes displaymode;
 
+extern int fmt_flags;
 extern int pcpu_stats;
 extern int overstrike;
 extern pid_t mypid;
Index: usr.bin/top/top.1
===================================================================
--- usr.bin/top/top.1
+++ usr.bin/top/top.1
@@ -1,5 +1,5 @@
 .\" $FreeBSD$
-.Dd September 21, 2019
+.Dd November 4, 2020
 .Dt TOP 1
 .Os
 .Sh NAME
@@ -11,6 +11,7 @@
 .Op Fl J Ar jail
 .Op Fl U Ar uid
 .Op Fl d Ar count
+.Op Fl g Ar string
 .Op Fl m Ar cpu|io
 .Op Fl s Ar time
 .Op Fl o Ar field
@@ -144,6 +145,15 @@
 .Ar count
 = 1
 no information is available about the percentage of time spent by the CPU in every state.
+.It Fl g Ar string
+Show only those processes that contain
+.Ar string
+in their command name.
+When used with
+.Fl a ,
+processes with command arguments that contain
+.Ar string
+will also be displayed.
 .It Fl s Ar time
 Set the delay between screen updates to
 .Ar time
@@ -239,10 +249,19 @@
 .It d
 Change the number of displays to show (prompt for new number).
 Remember that the next display counts as one, so typing
-.It d1
+.Dq d1
 will make
 .Nm
 show one final display and then immediately exit.
+.It /
+Display only processes where the command name matches a simple text
+pattern (prompt for pattern).
+When
+.Dq a
+is toggled, the command arguments will also be checked.
+Pressing
+.Dq enter
+with no input will display all processes.
 .It m
 Toggle the display between 'cpu' and 'io' modes.
 .It n or #
Index: usr.bin/top/top.c
===================================================================
--- usr.bin/top/top.c
+++ usr.bin/top/top.c
@@ -52,7 +52,7 @@
 /* The buffer that stdio will use */
 static char stdoutbuf[Buffersize];
 
-static int fmt_flags = 0;
+int fmt_flags = 0;
 int pcpu_stats = false;
 
 /* signal handling routines */
@@ -99,6 +99,7 @@
     { "batch", no_argument, NULL, 'b' },
     /* c reserved */
     { "displays", required_argument, NULL, 'd' },
+    { "cmd-filter", required_argument, NULL, 'g' },
     { "interactive", no_argument, NULL, 'i' },
     { "jail-id", no_argument, NULL, 'j' },
     { "display-mode", required_argument, NULL, 'm' },
@@ -229,6 +230,7 @@
     struct statics statics;
     void * processes;
 
+    char cmd[50];
     static char tempbuf1[50];
     static char tempbuf2[50];
 	sigset_t old_sigmask, new_sigmask;
@@ -312,7 +314,7 @@
 	    optind = 1;
 	}
 
-	while ((i = getopt_long(ac, __DECONST(char * const *, av), "CSIHPabijJ:nquvzs:d:U:m:o:p:Ttw", longopts, NULL)) != EOF)
+	while ((i = getopt_long(ac, __DECONST(char * const *, av), "CSIHPabijJ:nquvzs:d:g:U:m:o:p:Ttw", longopts, NULL)) != EOF)
 	{
 	    switch(i)
 	    {
@@ -363,6 +365,10 @@
 		    displays = i;
 		}
 		break;
+	      case 'g':
+		snprintf(cmd, sizeof(cmd), "%s", optarg);
+		ps.command = cmd;
+		break;
 	      case 'p': {
 		unsigned long long num;
 		const char *errstr;
@@ -464,7 +470,7 @@
 
 	      default:
 		errx(1, 
-"[-abCHIijnPqStuvwz] [-d count] [-m io | cpu] [-o field] [-p pid]\n"
+"[-abCgHIijnPqStuvwz] [-d count] [-g string] [-m io | cpu] [-o field] [-p pid]\n"
 "       [-s time] [-J jail] [-U username] [number]");
 	    }
 	}
@@ -976,6 +982,17 @@
 			    case CMD_user:
 				if (handle_user(tempbuf2, sizeof(tempbuf2)))
 				    no_command = true;
+				break;
+
+			    case CMD_filter:
+				new_message(MT_standout,
+				    " Filter by command (enter for all): ");
+
+				if (readline(cmd, sizeof(cmd), false) > 0) {
+					ps.command = cmd;
+					putchar('\r');
+				} else
+					clear_message();
 				break;
 
 			    case CMD_thrtog: