foamMonitor: Added -ascii and -size options

These options add the ability to show the plot in the terminal, and at
any size. This is intended to facilitate monitoring on remote machines
where launching an X11 application may not be convenient or possible.

Resolves feature request https://bugs.openfoam.org/view.php?id=3080

bin/foamMonitor

@@ -28,7 +28,7 @@
 # Description
 #     Monitor data with Gnuplot from time-value(s) graphs written by OpenFOAM
 #     e.g. by functionObjects
-#     - requires gnuplot, gnuplot_x11
+#     - requires gnuplot
 #
 #------------------------------------------------------------------------------
 usage() {
@@ -41,11 +41,13 @@ options:
   -title    | -t <title> set the graph title (default "Data Monitoring")
   -logscale | -l         plots data (y-axis) on log scale, e.g. for residuals
   -refresh  | -r <time>  refreshes display every <time> sec (default 10s)
-  -yrange   | -y <range> sets data (y-axis) <range>, format "[0:1]"
+  -yrange   | -y <range> sets data (y-axis) range, format "[0:1]"
+  -size     | -s <size>  set the size of the output plot, format "640,480"
+  -ascii    | -a         show the graph by printing ascii in the terminal
 
 Monitor data with Gnuplot from time-value(s) graphs written by OpenFOAM
 e.g. by functionObjects
-- requires gnuplot, gnuplot_x11
+- requires gnuplot
 
 Example:
   foamMonitor -l postProcessing/residuals/0/residuals.dat
@@ -62,7 +64,7 @@ error() {
 
 plotFileHeader() {
     cat<<EOF
-set term x11 1 font "helvetica,17" linewidth 1.5 persist noraise
+set term $gpterminal $size
 $logscale
 $yrange
 set title "$title"
@@ -91,6 +93,9 @@ refresh=10
 logscale=""
 yrange=""
 title="Data Monitoring"
+size=""
+gpterminal='x11 1 font "helvetica,17" linewidth 1.5 persist noraise'
+
 command -v gnuplot >/dev/null 2>&1 || error "Gnuplot not installed"
 
 # parse options
@@ -124,6 +129,15 @@ do
         yrange="set yrange $2"
         shift 2
         ;;
+    -s | -size)
+        [ "$#" -ge 2 ] || error "'$1' option requires an argument"
+        size="size $2"
+        shift 2
+        ;;
+    -a | -ascii)
+        gpterminal="dumb"
+        shift 1
+        ;;
     -*)
         error "unknown option: '$*'"
         ;;