i2psnark standalone: Raise open files ulimit

copied from i2prouter script

apps/i2psnark/launch-i2psnark

@@ -4,5 +4,33 @@
 # The file jetty-i2psnark.xml must be present in the current directory.
 # i2psnark will be accessed at http://127.0.0.1:8002/
 #
+
+# Raise the soft open files soft ulimit to this value, if able
+OPEN_FILES_ULIMIT=2048
+
+raiseopenfilesulimit() {
+    OPEN_FILES_SOFT=`ulimit -S -n` 2> /dev/null || return
+    if [ "$OPEN_FILES_SOFT" != "unlimited" ]
+    then
+        if [ "$OPEN_FILES_ULIMIT" -gt "$OPEN_FILES_SOFT" ]
+        then
+            OPEN_FILES_HARD=`ulimit -H -n` 2> /dev/null || return
+            if [ "$OPEN_FILES_HARD" != "unlimited" ]
+            then
+                if [ "$OPEN_FILES_ULIMIT" -gt "$OPEN_FILES_HARD" ]
+                then
+                    OPEN_FILES_ULIMIT="$OPEN_FILES_HARD"
+                fi
+            fi
+            if [ "$OPEN_FILES_ULIMIT" -gt "$OPEN_FILES_SOFT" ]
+            then
+                ulimit -S -n "$OPEN_FILES_ULIMIT" > /dev/null 2>&1
+            fi
+        fi
+    fi
+}
+
+raiseopenfilesulimit
+
 I2P="."
 java -jar "$I2P/i2psnark.jar"