Initial commit

snippets/is_number.sh

@@ -0,0 +1,57 @@
+#!/usr/bin/env bash
+
+is_number() {
+
+   return $(test ! -z "${1##*[!0-9]*}" > /dev/null 2>&1);
+
+   # - also possible
+   # -
+   #[[ ! -z "${1##*[!0-9]*}" ]] && return 0 || return 1
+   #return $([[ ! -z "${1##*[!0-9]*}" ]])
+}
+
+is_int() {
+   return $(test "$@" -eq "$@" > /dev/null 2>&1);
+}
+
+_int=-5
+_number=5
+_no_number=5a
+
+echo -e "\nTest of valid number (positiv integer)"
+if is_number $_number ; then
+   echo -e "\t$_number is a number"
+else
+   echo -e "\t$_number is NOT a number"
+fi
+if is_number $_int ; then
+   echo -e "\t$_int is a number"
+else
+   echo -e "\t$_int is NOT a number"
+fi
+if is_number $_no_number ; then
+   echo -e "\t$_no_number is a number"
+else
+   echo -e "\t$_no_number is NOT a number"
+fi
+
+
+echo -e "\nTest of valid integer"
+if is_int $_number ; then
+   echo -e "\t$_number is a valid integer"
+else
+   echo -e "\t$_number is NOT a valid integer"
+fi
+if is_int $_int ; then
+   echo -e "\t$_int is a valid integer"
+else
+   echo -e "\t$_int is NOT a valid integer"
+fi
+if is_int $_no_number ; then
+   echo -e "\t$_no_number is a valid integer"
+else
+   echo -e "\t$_no_number is NOT a valid integer"
+fi
+
+echo ""
+exit 0