let xargs run only when matches were found

1 files changed, 2 insertions, 2 deletions

diff --git a/update_jdn.sh b/update_jdn.sh
index e910f5b1..8eddb24e 100755
--- a/update_jdn.sh
+++ b/update_jdn.sh
@@ -83,10 +83,10 @@ explain "Jenkins jobs updated."
 # crappy tests for checking that jenkins-job-builder works correctly
 #
 #wc -m counts one byte too many, so we substract one
-let DEFINED_MY_TRIGGERS=$(grep my_trigger: *.yaml|wc -l)+$(grep my_trigger: *.yaml|grep , |xargs echo | sed 's/[^,]//g'| wc -m)-1
+let DEFINED_MY_TRIGGERS=$(grep my_trigger: *.yaml|wc -l)+$(grep my_trigger: *.yaml|grep , |xargs -r echo | sed 's/[^,]//g'| wc -m)-1
 DEFINED_DI_TRIGGERS=$(grep "defaults: d-i-manual-html" d-i.yaml|wc -l)
 let DEFINED_TRIGGERS=DEFINED_MY_TRIGGERS+DEFINED_DI_TRIGGERS
-let CONFIGURED_TRIGGERS=$(grep \<childProjects /var/lib/jenkins/jobs/*/config.xml|wc -l)+$(grep  \<childProjects /var/lib/jenkins/jobs/*/config.xml |grep , |xargs echo | sed 's/[^,]//g'| wc -m)-1
+let CONFIGURED_TRIGGERS=$(grep \<childProjects /var/lib/jenkins/jobs/*/config.xml|wc -l)+$(grep  \<childProjects /var/lib/jenkins/jobs/*/config.xml |grep , |xargs -r echo | sed 's/[^,]//g'| wc -m)-1
 if [ "$DEFINED_TRIGGERS" != "$CONFIGURED_TRIGGERS" ] ; then
 	figlet Warning
 	explain "Number of defined triggers ($DEFINED_TRIGGERS) differs from currently configured triggers ($CONFIGURED_TRIGGERS), please investigate."