Added check for (La)TeX installation.

install

@@ -81,6 +81,34 @@ check_isabelle_version() {
     fi
 }
 
+check_pdftex() {
+    echo "* Checking (La)TeX installation:"
+    OLDDIR=`pwd`
+    DIR=`mktemp -d`
+    cd $DIR; 
+    pdftex -interaction=nonstopmode \\expanded{Success}\\end > /dev/null
+    if [ $? -eq 0 ]; then
+        echo "  Success: pdftex supports \\expanded{} primitive."
+    else 
+        cd $OLDDIR
+        echo "  WARNING:"
+        echo "    The version of pdf(La)TeX you are using is outdated (and does"
+        echo "    not support the \\expanded primitive). It is not supported by the"
+        echo "    current version of Isabelle/DOF. Please install a supported TeX"
+        echo "    distribution (e.g., TeXLive 2019 or later)."
+        echo 
+        read -p "    Still continue (y/N)? " -n 1 -r
+        echo 
+        if [[ $REPLY =~ ^[Yy]$ ]];
+        then 
+            echo "    Continuing installation on your OWN risk."
+        else
+            exit_error
+        fi
+    fi
+    cd $OLDDIR
+}
+
 check_afp_entries() {
     echo "* Checking availability of AFP entries:"
     missing=""
@@ -239,8 +267,9 @@ echo ""
 echo "Isabelle/DOF Installer"
 echo "======================"
 check_isabelle_version
+check_pdftex
 if [ "$SKIP" = "true" ]; then
-  echo "  Warning: skipping installation of Isabelle patch and AFP entries."
+  echo "* Warning: skipping installation of Isabelle patch and AFP entries."
 else
   check_isa_dof_patch
   check_afp_entries