sbm

commit 62e66fce04b47d592ae7ae79b04d7deca80092dc
parent c1a0c5055310876235e7de09a120cf21db105001
Author: sin <sin@2f30.org>
Date:   Fri, 19 Feb 2016 11:35:00 +0000

Add [-c count] option to limit the number of samples

Diffstat:
M
sbm.1
 | 
9
++++++++-
M
sbm.c
 | 
19
++++++++++++++++---

2 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/sbm.1 b/sbm.1
@@ -1,4 +1,4 @@
-.Dd Feb 16, 2016
+.Dd Feb 19, 2016
 .Dt SBM 1
 .Os
 .Sh NAME
@@ -7,6 +7,7 @@
 .Sh SYNOPSIS
 .Nm sbm
 .Op Fl i Ar interface
+.Op Fl c Ar count
 .Sh DESCRIPTION
 .Nm
 is a simple bandwidth monitor.
@@ -15,6 +16,12 @@ is a simple bandwidth monitor.
 .It Fl i Ar interface
 Monitor the selected interface.  If not provided the first
 active, non-loopback interface will be used.
+.It Fl c Ar count
+Stop monitoring after
+.Ar count
+samples.  If
+.Ar count
+is 0, it will loop forever.  This is the default.
 .El
 .Sh AUTHORS
 .An Dimitris Papastamos Aq Mt sin@2f30.org
diff --git a/sbm.c b/sbm.c
@@ -27,7 +27,9 @@
 #endif
 
 #include <err.h>
+#include <errno.h>
 #include <ifaddrs.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -175,12 +177,13 @@ print(char *ifname, unsigned long long rxbits, unsigned long long txbits,
 }
 
 void
-loop(char *ifname)
+loop(char *ifname, long count)
 {
 	unsigned long long oldrxbytes, rxbytes;
 	unsigned long long oldtxbytes, txbytes;
 	unsigned long long oldrxpps, rxpps;
 	unsigned long long oldtxpps, txpps;
+	long n = 0;
 
 	sample(ifname, &oldrxbytes, &oldtxbytes, &oldrxpps, &oldtxpps);
 	for (;;) {
@@ -195,13 +198,15 @@ loop(char *ifname)
 		oldtxbytes = txbytes;
 		oldrxpps = rxpps;
 		oldtxpps = txpps;
+		if (count && ++n >= count)
+			break;
 	}
 }
 
 void
 usage(void)
 {
-	fprintf(stderr, "usage: %s [-i interface]\n", argv0);
+	fprintf(stderr, "usage: %s [-c count] [-i interface]\n", argv0);
 	exit(1);
 }
 
@@ -209,8 +214,16 @@ int
 main(int argc, char *argv[])
 {
 	char ifname[IF_NAMESIZE] = "";
+	char *end;
+	long count = 0;
 
 	ARGBEGIN {
+	case 'c':
+		errno = 0;
+		count = strtol(EARGF(usage()), &end, 10);
+		if (*end != '\0' || errno)
+			errx(1, "invalid count");
+		break;
 	case 'i':
 		strncpy(ifname, EARGF(usage()), sizeof(ifname));
 		ifname[IF_NAMESIZE - 1] = '\0';
@@ -220,6 +233,6 @@ main(int argc, char *argv[])
 	} ARGEND
 
 	scan(ifname);
-	loop(ifname);
+	loop(ifname, count);
 	return 0;
 }