diff --git a/deviate.c b/deviate.c
index c9ae3c0c..5f695729 100644
--- a/deviate.c
+++ b/deviate.c
@@ -455,6 +455,7 @@ calcdiff(struct tstat *devstat, const struct tstat *curstat,
 	devstat->cpu.cgcpuweight = curstat->cpu.cgcpuweight;
 	devstat->cpu.cgcpumax    = curstat->cpu.cgcpumax;
 	devstat->cpu.cgcpumaxr   = curstat->cpu.cgcpumaxr;
+	devstat->cpu.nropen      = curstat->cpu.nropen;
 
 	if (curstat->cpu.wchan[0])
 		strcpy(devstat->cpu.wchan, curstat->cpu.wchan);
diff --git a/json.c b/json.c
index 2d4757b4..bdc942cd 100644
--- a/json.c
+++ b/json.c
@@ -1030,6 +1030,7 @@ static void json_print_PRC(char *hp, struct sstat *ss, struct tstat *ps, int nac
 			"\"blkdelay\": %lld, "
 			"\"nvcsw\": %llu, "
 			"\"nivcsw\": %llu, "
+			"\"nropen\": %d, "
 			"\"sleepavg\": %d}",
 			ps->gen.pid,
 			ps->cpu.utime,
@@ -1043,6 +1044,7 @@ static void json_print_PRC(char *hp, struct sstat *ss, struct tstat *ps, int nac
 			ps->cpu.blkdelay*1000/hertz,
 			ps->cpu.nvcsw,
 			ps->cpu.nivcsw,
+			ps->cpu.nropen,
 			ps->cpu.sleepavg);
 	}
 
diff --git a/man/atop.1 b/man/atop.1
index c5a8ca2d..5368f852 100644
--- a/man/atop.1
+++ b/man/atop.1
@@ -1661,6 +1661,11 @@ Time that the process has been finished. If the process is still running,
 this field shows `active'.
 .PP
 .TP 9
+.B NROPEN
+Current number of opened file descriptors (fds) for each process, at least 0.
+As each thread has the same fds with its process, this filed shows `-`.
+.PP
+.TP 9
 .B ENVID
 Virtual environment identified (OpenVZ only).
 .PP
diff --git a/parseable.c b/parseable.c
index 0cbca48b..fe9adcd7 100644
--- a/parseable.c
+++ b/parseable.c
@@ -785,7 +785,7 @@ print_PRC(char *hp, struct sstat *ss, struct tstat *ps, int nact)
 	for (i=0; i < nact; i++, ps++)
 	{
 		printf("%s %d %s %c %u %lld %lld %d %d %d %d %d %d %d %c "
-		       "%llu %s %llu %d %d %llu %llu\n",
+		       "%llu %s %llu %d %d %d %llu %llu\n",
 			hp,
 			ps->gen.pid,
 			spaceformat(ps->gen.name, namout),
@@ -804,6 +804,7 @@ print_PRC(char *hp, struct sstat *ss, struct tstat *ps, int nact)
 			ps->cpu.rundelay,
 			spaceformat(ps->cpu.wchan, wchanout),
 			ps->cpu.blkdelay,
+			ps->cpu.nropen,
 			cgroupv2max(ps->gen.isproc, ps->cpu.cgcpumax),
 			cgroupv2max(ps->gen.isproc, ps->cpu.cgcpumaxr),
 			ps->cpu.nvcsw,
diff --git a/photoproc.c b/photoproc.c
index 5219f80d..c4b01a74 100644
--- a/photoproc.c
+++ b/photoproc.c
@@ -63,6 +63,7 @@ static int	proccont(struct tstat *);
 static void	proccmd(struct tstat *);
 static void	procsmaps(struct tstat *);
 static void	procwchan(struct tstat *);
+static void	procfd(struct tstat *);
 static count_t	procschedstat(struct tstat *);
 static int	proccgroupv2(struct tstat *);
 static struct cgroupv2vals *
@@ -218,6 +219,8 @@ photoproc(struct tstat *tasklist, int maxtask)
                 if (getwchan)
                 	procwchan(curtask);
 
+		procfd(curtask);
+
 		// read network stats from netatop
 		netatop_gettask(curtask->gen.tgid, 'g', curtask);
 
@@ -981,6 +984,38 @@ procschedstat(struct tstat *curtask)
 	return curtask->cpu.rundelay;
 }
 
+/*
+** get current number of opened file descriptors for process
+** to monitor if fd leaks.
+** Considering users may set the max number of open files to
+** a very large number, we regard MAX_OPEN to be 10000.
+*/
+#define MAX_OPEN 10000
+
+static void
+procfd(struct tstat *curtask)
+{
+	DIR *dirp;
+	struct dirent *dentry;
+	int fd_num = 0;
+
+	if ( (dirp = opendir("fd")) )
+	{
+		while ( (dentry = readdir(dirp)) )
+		{
+			if ( isdigit(dentry->d_name[0]) )
+				fd_num++;
+
+			if ( fd_num >= MAX_OPEN )
+				break;
+		}
+
+		curtask->cpu.nropen = fd_num;
+
+		closedir(dirp);
+	}
+}
+
 /*
 ** CGROUP V2 specific items
 */
diff --git a/photoproc.h b/photoproc.h
index b20e2654..2815dedd 100644
--- a/photoproc.h
+++ b/photoproc.h
@@ -82,7 +82,8 @@ struct tstat {
 		int	cgcpuweight;	/* cgroup cpu.weight            */
 		int	cgcpumax;	/* cgroup cpu.max percentage    */
 		int	cgcpumaxr;	/* restrictive percentage       */
-		int	ifuture[3];	/* reserved for future use	*/
+		int	nropen;		/* number of opened files       */
+		int	ifuture[2];	/* reserved for future use	*/
 		char	wchan[16];	/* wait channel string    	*/
 		count_t	rundelay;	/* schedstat rundelay (nanosec)	*/
 		count_t	blkdelay;	/* blkio delay (ticks)		*/
diff --git a/showlinux.c b/showlinux.c
index 3d0b0947..185b19c6 100644
--- a/showlinux.c
+++ b/showlinux.c
@@ -423,6 +423,7 @@ proc_printdef *allprocpdefs[]=
 	&procprt_STTIME,
 	&procprt_ENDATE,
 	&procprt_ENTIME,
+	&procprt_NROPEN,
 	&procprt_THR,
 	&procprt_TRUN,
 	&procprt_TSLPI,
@@ -1300,7 +1301,7 @@ priphead(int curlist, int totlist, char *showtype, char *showorder,
 			"RUID:8 RGID:8 EUID:5 EGID:4 "
      			"SUID:3 SGID:2 FSUID:3 FSGID:2 "
                         "STDATE:7 STTIME:7 ENDATE:5 ENTIME:5 "
-			"ST:6 EXC:6 S:6 SORTITEM:10 CMD:10", 
+			"NROPEN:5 ST:6 EXC:6 S:6 SORTITEM:10 CMD:10",
                         "built-in varprocs");
 
                 make_proc_prints(cmdprocs, MAXITEMS,
diff --git a/showlinux.h b/showlinux.h
index f275a82a..87294548 100644
--- a/showlinux.h
+++ b/showlinux.h
@@ -418,6 +418,7 @@ extern proc_printdef procprt_STDATE;
 extern proc_printdef procprt_STTIME;
 extern proc_printdef procprt_ENDATE;
 extern proc_printdef procprt_ENTIME;
+extern proc_printdef procprt_NROPEN;
 extern proc_printdef procprt_THR;
 extern proc_printdef procprt_TRUN;
 extern proc_printdef procprt_TSLPI;
diff --git a/showprocs.c b/showprocs.c
index da88d171..72bbe804 100644
--- a/showprocs.c
+++ b/showprocs.c
@@ -115,6 +115,8 @@ char *procprt_ENDATE_a(struct tstat *, int, int);
 char *procprt_ENDATE_e(struct tstat *, int, int);
 char *procprt_ENTIME_a(struct tstat *, int, int);
 char *procprt_ENTIME_e(struct tstat *, int, int);
+char *procprt_NROPEN_a(struct tstat *, int, int);
+char *procprt_NROPEN_e(struct tstat *, int, int);
 char *procprt_THR_a(struct tstat *, int, int);
 char *procprt_THR_e(struct tstat *, int, int);
 char *procprt_TRUN_a(struct tstat *, int, int);
@@ -1235,6 +1237,32 @@ proc_printdef procprt_ENTIME =
    { " ENTIME ", "ENTIME", procprt_ENTIME_a, procprt_ENTIME_e, 8 };
 /***************************************************************/
 char *
+procprt_NROPEN_a(struct tstat *curstat, int avgval, int nsecs)
+{
+	static char buf[64];
+
+	if (curstat->gen.isproc)
+		sprintf(buf, "%*d", procprt_NROPEN.width, curstat->cpu.nropen);
+	else
+		sprintf(buf, "%*s", procprt_NROPEN.width, "-");
+
+	return buf;
+}
+
+char *
+procprt_NROPEN_e(struct tstat *curstat, int avgval, int nsecs)
+{
+	static char buf[64];
+
+	sprintf(buf, "%*s", procprt_NROPEN.width, "-");
+
+	return buf;
+}
+
+proc_printdef procprt_NROPEN =
+   { " NROPEN", "NROPEN", procprt_NROPEN_a, procprt_NROPEN_e, 7 };
+/***************************************************************/
+char *
 procprt_THR_a(struct tstat *curstat, int avgval, int nsecs)
 {
         static char buf[15];