util name check

ch6/stackcount_eg.sh

@@ -1,12 +1,24 @@
 #!/bin/bash
 # Linux Kernel Programming, 2E
 # Simple wrapper script to try out stackcount[-bpfcc].
+# Lightly tested ONLY for Ubuntu x86_64...
+# TODO:
+# [ ] work properly on Fedora distro..
+#
 # For details, refer to the book, Ch 6.
 # (c) Kaiwan NB, MIT
+name=$(basename $0)
 set -euo pipefail
 SEP="--------------------------------------------------------------------------------"
 # Ubuntu specific name for BCC tool(s), adjust as required for other distros
-PRG=stackcount-bpfcc
+PRG=stackcount
+which ${PRG} >/dev/null 2>&1 || {
+	which ${PRG}-bpfcc >/dev/null 2>&1 && PRG=stackcount-bpfcc || {
+		echo "FATAL: requires stackcount[-bpfcc] to be installed."
+		exit 1
+	}
+}
+
 which ${PRG} >/dev/null
 [ $? -ne 0 ] && {
   echo "${name}: oops, ${PRG} not installed? aborting..."
@@ -22,8 +34,13 @@ ${SEP}"
 eval ${1}
 }
 
+HDR="${name}: NOTE: Lightly tested ONLY for Ubuntu x86_64
+(Patience please, it can take a while...)
+"
+echo "${HDR}"
+
 echo "Running ping in the background..."
-ping altavista.com >/dev/null 2>&1 &
+ping yahoo.com >/dev/null 2>&1 &
 
 cmd="sudo ${PRG} --regex 'net_[rt]x_action' --duration 3 --perpid --delimited 2>/dev/null"
 desc="Show net_rx_action() and net_tx_action() (the NET_RX_SOFTIRQ and NET_TX_SOFTIRQ softirq's) call stacks:"