phits-run runs both with and without GNU parallel

mctools/phits/phits-run.sh

@@ -4,8 +4,8 @@ usage()
 {
     echo "Usage: $(basename $0) file.inp [prefix] [njobs]"
     echo "       file.inp: PHITS input file. Must contain the 'rseed = RSEED' string in the [Parameters] section"
-    echo "       prefix:   temporary folder prefix"
-    echo "       njobs:    number of jobs to run. Default=number of cores (output of nproc)"
+    echo "       prefix:   temporary folder prefix. Default: 'case'"
+    echo "       njobs:    number of jobs to run. Default: number of cores (output of nproc)"
     exit 1
 }
 
@@ -31,4 +31,35 @@ else
     njobs=$(nproc)
 fi
 
-echo $inp $prefix $njobs
+rseed=$(grep rseed $inp | xargs | tr -d '[:blank:]')
+
+if echo $rseed | grep -qx "rseed=RSEED" 2>/dev/null; then
+    true
+else
+    echo "ERROR: The 'rseed = RSEED' string not found in $inp"
+    usage
+fi
+
+for ((i=1; i<=$njobs; i++)); do
+    d=$prefix$i
+    if [ -d $d ]; then
+	echo "ERROR: $d folder already exists"
+	exit 2
+    else
+	mkdir -p $d
+	cat $inp | sed "s;RSEED;$i;" > $d/phits.inp
+    fi
+done
+
+if which parallel > /dev/null; then
+    parallel "cd {} && phits.sh phits.inp" ::: $prefix*
+else
+    h=$(pwd)
+    for d in $prefix*; do
+	echo $d
+	cd $d
+	phits.sh phits.inp
+	cd $h
+    done
+    wait $(jobs -rp)
+fi