added built-in and expr functions to do math

3 files changed, 57 insertions, 1 deletions

diff --git a/source/1.0/doc/CHANGES-1.0.txt b/source/1.0/doc/CHANGES-1.0.txt
index a259c2c..5a125e6 100644
--- a/source/1.0/doc/CHANGES-1.0.txt
+++ b/source/1.0/doc/CHANGES-1.0.txt
@@ -44,6 +44,8 @@ Issue #22. Fixed broken testGetFlagInfo() test.
 Created alternate validFloat() and validInt() functions that use shell built-ins
 where possible to increase performance and reduce the usage of the expr command.
 
+Added separate built-in and expr functions for doing math.
+
 
 Changes with 1.0.3
 ------------------
diff --git a/source/1.0/src/shflags b/source/1.0/src/shflags
index 1955839..814f450 100644
--- a/source/1.0/src/shflags
+++ b/source/1.0/src/shflags
@@ -118,9 +118,11 @@ fi
 # can we use built-ins?
 ( echo "${FLAGS_TRUE#0}"; ) >/dev/null 2>&1
 if [ $? -eq ${FLAGS_TRUE} ]; then
+  __FLAGS_FX_MATH='_flags_mathBuiltin'
   __FLAGS_FX_VALID_FLOAT='_flags_validFloatBuiltin'
   __FLAGS_FX_VALID_INT='_flags_validIntBuiltin'
 else
+  __FLAGS_FX_MATH='_flags_mathExpr'
   __FLAGS_FX_VALID_FLOAT='_flags_validFloatExpr'
   __FLAGS_FX_VALID_INT='_flags_validIntExpr'
 fi
@@ -756,7 +758,7 @@ _flags_parseGetopt()
   # properly give user access to non-flag arguments mixed in between flag
   # arguments. Its usage was replaced by FLAGS_ARGV, and it is being kept only
   # for backwards compatibility reasons.
-  FLAGS_ARGC=`${FLAGS_EXPR_CMD} $# - 1 - ${_flags_argc_}`
+  FLAGS_ARGC=`${__FLAGS_FX_MATH} $# - 1 - ${_flags_argc_}`
 
   # handle options. note options with values must do an additional shift
   while true; do
@@ -883,6 +885,31 @@ _flags_parseGetopt()
   return ${flags_return}
 }
 
+# Perform some path using built-ins.
+#
+# Args:
+#   $@: string: math expression to evaluate
+# Returns:
+#   string: the result
+_flags_mathBuiltin()
+{
+  # Variable assignment is needed as workaround for Solaris Bourne shell, which
+  # cannot parse a bare $((expression)).
+  _flags_expr_='$(($@))'
+  eval echo ${_flags_expr_}
+}
+
+# Perform some path using expr.
+#
+# Args:
+#   $@: string: math expression to evaluate
+# Returns:
+#   string: the result
+_flags_mathExpr()
+{
+  eval ${FLAGS_EXPR_CMD} $@
+}
+
 #------------------------------------------------------------------------------
 # public functions
 #
diff --git a/source/1.0/src/shflags_test_private.sh b/source/1.0/src/shflags_test_private.sh
index f353bb3..7065940 100755
--- a/source/1.0/src/shflags_test_private.sh
+++ b/source/1.0/src/shflags_test_private.sh
@@ -179,6 +179,33 @@ testValidIntExpr()
   _testValidInt _flags_validIntExpr
 }
 
+_testMath()
+{
+  fx=$1
+
+  assertEquals 2 `${fx} 1 + 1`
+  assertEquals 2 `${fx} '1 + 1'`
+
+  assertNotEquals 3 `${fx} 1 + 1`
+  assertNotEquals 3 `${fx} '1 + 1'`
+}
+
+testMathBuiltin()
+{
+  # Are we running a shell that can handle a built-in version? The Solaris
+  # Bourne shell for one does not support what we need.
+  if [ "${__FLAGS_FX_VALID_INT}" != '_flags_validIntBuiltin' ]; then
+    echo 'SKIPPED: this shell does not support the necessary builtins'
+    return
+  fi
+  _testMath _flags_mathBuiltin
+}
+
+testMathExpr()
+{
+  _testMath _flags_mathExpr
+}
+
 #------------------------------------------------------------------------------
 # suite functions
 #