diff --git a/tutorials/combustion/chemFoam/gri/validation/createGraph b/tutorials/combustion/chemFoam/gri/validation/createGraph
index d0fb9cc013..1ef428f28d 100755
--- a/tutorials/combustion/chemFoam/gri/validation/createGraph
+++ b/tutorials/combustion/chemFoam/gri/validation/createGraph
@@ -1,10 +1,9 @@
 #!/bin/sh
 
-if ! which gnuplot > /dev/null 2>&1
-then
-    echo "gnuplot not found - skipping graph creation" >&2
+command -v gnuplot >/dev/null 2>&1 || {
+    echo "gnuplot not found - skipping graph creation" 1>&2
     exit 1
-fi
+}
 
 gnuplot<<EOF
     set terminal postscript eps color enhanced "Helveicta,20"
diff --git a/tutorials/combustion/chemFoam/h2/validation/createGraph b/tutorials/combustion/chemFoam/h2/validation/createGraph
index bbb36218fa..29c39828f3 100755
--- a/tutorials/combustion/chemFoam/h2/validation/createGraph
+++ b/tutorials/combustion/chemFoam/h2/validation/createGraph
@@ -1,10 +1,10 @@
 #!/bin/sh
 
-if ! which gnuplot > /dev/null 2>&1
-then
-    echo "gnuplot not found - skipping graph creation" >&2
+# Test if gnuplot exists on the system
+command -v gnuplot >/dev/null 2>&1 || {
+    echo "gnuplot not found - skipping graph creation" 1>&2
     exit 1
-fi
+}
 
 gnuplot<<EOF
     set terminal postscript eps color enhanced "Helvetica,20"
diff --git a/tutorials/combustion/chemFoam/ic8h18/validation/createGraph b/tutorials/combustion/chemFoam/ic8h18/validation/createGraph
index 4606eac7d3..0c6d9b3d3d 100755
--- a/tutorials/combustion/chemFoam/ic8h18/validation/createGraph
+++ b/tutorials/combustion/chemFoam/ic8h18/validation/createGraph
@@ -1,10 +1,10 @@
 #!/bin/sh
 
-if ! which gnuplot > /dev/null 2>&1
-then
-    echo "gnuplot not found - skipping graph creation" >&2
+# Test if gnuplot exists on the system
+command -v gnuplot >/dev/null 2>&1 || {
+    echo "gnuplot not found - skipping graph creation" 1>&2
     exit 1
-fi
+}
 
 gnuplot<<EOF
     set terminal postscript eps color enhanced "Helvetica,20"
diff --git a/tutorials/combustion/chemFoam/ic8h18_TDAC/validation/createGraph b/tutorials/combustion/chemFoam/ic8h18_TDAC/validation/createGraph
index d406960eff..43e3c36e10 100755
--- a/tutorials/combustion/chemFoam/ic8h18_TDAC/validation/createGraph
+++ b/tutorials/combustion/chemFoam/ic8h18_TDAC/validation/createGraph
@@ -1,10 +1,10 @@
 #!/bin/sh
 
-if ! which gnuplot > /dev/null 2>&1
-then
-    echo "gnuplot not found - skipping graph creation" >&2
+# Test if gnuplot exists on the system
+command -v gnuplot >/dev/null 2>&1 || {
+    echo "gnuplot not found - skipping graph creation" 1>&2
     exit 1
-fi
+}
 
 gnuplot<<EOF
     set terminal postscript eps color enhanced "Helvetica,20"
diff --git a/tutorials/combustion/chemFoam/nc7h16/validation/createGraph b/tutorials/combustion/chemFoam/nc7h16/validation/createGraph
index b2f8a4d945..5564fffd7b 100755
--- a/tutorials/combustion/chemFoam/nc7h16/validation/createGraph
+++ b/tutorials/combustion/chemFoam/nc7h16/validation/createGraph
@@ -1,10 +1,10 @@
 #!/bin/sh
 
-if ! which gnuplot > /dev/null 2>&1
-then
-    echo "gnuplot not found - skipping graph creation" >&2
+# Test if gnuplot exists on the system
+command -v gnuplot >/dev/null 2>&1 || {
+    echo "gnuplot not found - skipping graph creation" 1>&2
     exit 1
-fi
+}
 
 gnuplot<<EOF
     set terminal postscript eps color enhanced "Helvetica,20"
diff --git a/tutorials/combustion/fireFoam/LES/compartmentFire/validation/createGraphs b/tutorials/combustion/fireFoam/LES/compartmentFire/validation/createGraphs
index cbae27d840..c1f1b64998 100755
--- a/tutorials/combustion/fireFoam/LES/compartmentFire/validation/createGraphs
+++ b/tutorials/combustion/fireFoam/LES/compartmentFire/validation/createGraphs
@@ -53,12 +53,11 @@ EOF
 }
 
 
-# test if gnuplot exists on the system
-if ! which gnuplot > /dev/null 2>&1
-then
-    echo "gnuplot not found - skipping graph creation" >&2
+# Test if gnuplot exists on the system
+command -v gnuplot >/dev/null 2>&1 || {
+    echo "gnuplot not found - skipping graph creation" 1>&2
     exit 1
-fi
+}
 
 SETSDIRT="../postProcessing/thermoCouple"
 
diff --git a/tutorials/heatTransfer/buoyantSimpleFoam/buoyantCavity/validation/createGraphs b/tutorials/heatTransfer/buoyantSimpleFoam/buoyantCavity/validation/createGraphs
index 693c8dbfdf..7016a3610a 100755
--- a/tutorials/heatTransfer/buoyantSimpleFoam/buoyantCavity/validation/createGraphs
+++ b/tutorials/heatTransfer/buoyantSimpleFoam/buoyantCavity/validation/createGraphs
@@ -85,20 +85,18 @@ EOF
 
 echo "createGraphs:"
 
-# test if gnuplot exists on the system
-if ! which gnuplot > /dev/null 2>&1
-then
-    echo "FOAM FATAL ERROR: gnuplot not found - skipping graph creation" >&2
+# Test if gnuplot exists on the system
+command -v gnuplot >/dev/null 2>&1 || {
+    echo "FOAM FATAL ERROR: gnuplot not found - skipping graph creation" 1>&2
     exit 1
-fi
+}
 
 SETSDIR="../postProcessing/sample"
 
-if [ ! -d $SETSDIR ]
-then
-    echo "FOAM FATAL ERROR: result sets not available in directory $SETSDIR" >&2
+[ -d "$SETSDIR" ] || {
+    echo "FOAM FATAL ERROR: result sets not available in directory $SETSDIR" 1>&2
     exit 1
-fi
+}
 
 # paths to data
 LATESTTIME=$(ls $SETSDIR)
diff --git a/tutorials/heatTransfer/chtMultiRegionSimpleFoam/jouleHeatingSolid/createGraphs b/tutorials/heatTransfer/chtMultiRegionSimpleFoam/jouleHeatingSolid/createGraphs
index 04bbc57ea0..1c39ff49a9 100755
--- a/tutorials/heatTransfer/chtMultiRegionSimpleFoam/jouleHeatingSolid/createGraphs
+++ b/tutorials/heatTransfer/chtMultiRegionSimpleFoam/jouleHeatingSolid/createGraphs
@@ -30,28 +30,25 @@
 #     Joule heating case
 #
 #------------------------------------------------------------------------------
-
 cd ${0%/*} || exit 1    # Run from this directory
 
 # Stop on first error
 set -e
 
-# test if gnuplot exists on the system
-if ! which gnuplot > /dev/null 2>&1
-then
-    echo "FOAM FATAL ERROR: gnuplot not found - skipping graph creation" >&2
+# Test if gnuplot exists on the system
+command -v gnuplot >/dev/null 2>&1 || {
+    echo "FOAM FATAL ERROR: gnuplot not found - skipping graph creation" 1>&2
     exit 1
-fi
+}
 
 
 echo "Creating graph"
 OFDATA='postProcessing/sample1/solid/20000/centreLine_T_jouleHeatingSource:V_jouleHeatingSource:sigma.xy'
 
-if [ ! -f "$OFDATA" ]
-then
-    echo "FOAM FATAL ERROR: OpenFOAM results not available in $OFDATA" >&2
+[ -f "$OFDATA" ] || {
+    echo "FOAM FATAL ERROR: OpenFOAM results not available in $OFDATA" 1>&2
     exit 1
-fi
+}
 
 gnuplot<<EOF
 set terminal postscript eps color enhanced
diff --git a/tutorials/incompressible/boundaryFoam/boundaryWallFunctionsProfile/Allrun b/tutorials/incompressible/boundaryFoam/boundaryWallFunctionsProfile/Allrun
index ae838574d9..7f68f70913 100755
--- a/tutorials/incompressible/boundaryFoam/boundaryWallFunctionsProfile/Allrun
+++ b/tutorials/incompressible/boundaryFoam/boundaryWallFunctionsProfile/Allrun
@@ -36,12 +36,11 @@ done
 
 
 # create validation plot
-# test if gnuplot exists on the system
-if ! which gnuplot > /dev/null 2>&1
-then
-    echo "gnuplot not found - skipping graph creation" >&2
+# Test if gnuplot exists on the system
+command -v gnuplot >/dev/null 2>&1 || {
+    echo "gnuplot not found - skipping graph creation" 1>&2
     exit 1
-fi
+}
 
 graphName="OF_vs_ANALYTICAL.eps"
 
diff --git a/tutorials/incompressible/pimpleFoam/laminar/planarPoiseuille/validation/createGraph b/tutorials/incompressible/pimpleFoam/laminar/planarPoiseuille/validation/createGraph
index a30402600e..d6402c1b4d 100755
--- a/tutorials/incompressible/pimpleFoam/laminar/planarPoiseuille/validation/createGraph
+++ b/tutorials/incompressible/pimpleFoam/laminar/planarPoiseuille/validation/createGraph
@@ -3,11 +3,11 @@
 tail -n +4 ../postProcessing/probes/0/U  | \
     tr -s " " | tr -d '(' | cut -d " " -f2-3 > ../Numerical.dat
 
-if ! which gnuplot > /dev/null 2>&1
-then
-    echo "gnuplot not found - skipping graph creation" >&2
+# Test if gnuplot exists on the system
+command -v gnuplot >/dev/null 2>&1 || {
+    echo "gnuplot not found - skipping graph creation" 1>&2
     exit 1
-fi
+}
 
 gnuplot<<EOF
     set terminal postscript eps color enhanced "Helvetica,20"
diff --git a/tutorials/incompressible/simpleFoam/T3A/validation/createGraphs b/tutorials/incompressible/simpleFoam/T3A/validation/createGraphs
index 20e1699f3d..40bb778403 100755
--- a/tutorials/incompressible/simpleFoam/T3A/validation/createGraphs
+++ b/tutorials/incompressible/simpleFoam/T3A/validation/createGraphs
@@ -1,10 +1,10 @@
 #!/bin/sh
 
-if ! which gnuplot > /dev/null 2>&1
-then
-    echo "gnuplot not found - skipping graph creation" >&2
+# Test if gnuplot exists on the system
+command -v gnuplot >/dev/null 2>&1 || {
+    echo "gnuplot not found - skipping graph creation" 1>&2
     exit 1
-fi
+}
 
 gnuplot<<EOF
     set term post enhanced color solid linewidth 2.0 20