STYLE: more consistent shell style in tutorial run/clean scripts

tutorials/multiphase/interFoam/ras/Allrun

@@ -1,14 +1,17 @@
 #!/bin/sh
+cd ${0%/*} || exit 1    # run from this directory
+
 # Source tutorial run functions
 . $WM_PROJECT_DIR/bin/tools/RunFunctions
 
 # Set application name
 application="interFoam"
 
-setDamBreakFine ()
+setDamBreakFine()
 {
     blockMeshDict="constant/polyMesh/blockMeshDict"
     controlDict="system/controlDict"
+
     sed \
     -e s/"23 8"/"46 10"/g \
     -e s/"19 8"/"40 10"/g \
@@ -17,6 +20,7 @@ setDamBreakFine ()
     -e s/"19 42\(.*\) 1 1)"/"40 76\1 2 1)"/g \
     $blockMeshDict > temp.$$
     mv temp.$$ $blockMeshDict
+
     sed \
     -e s/"\(deltaT[ \t]*\) 0.001;"/"\1 5e-04;"/g \
     -e s/"\(endTime[ \t]*\) 1;"/"\1 0.4;"/g \
@@ -25,19 +29,24 @@ setDamBreakFine ()
 }
 
 # Do damBreak
-(cd damBreak && foamRunTutorials)
+( cd damBreak && foamRunTutorials )
 
 # Clone case
 cloneCase damBreak damBreakFine
 
-cd damBreakFine
+(
+    cd damBreakFine || exit
+
     # Modify case
     setDamBreakFine
     cp ../damBreak/0/alpha1.org 0/alpha1
+
     # And execute
     runApplication blockMesh
     runApplication setFields
     runApplication decomposePar
     runParallel $application 4
     runApplication reconstructPar
-cd ..
+)
+
+# ----------------------------------------------------------------- end-of-file