[PATCH] Simplify edksetup.sh

[Rebecca Cran <rebecca@bsdio.com>]

o Use '$SCRIPTNAME' consistently instead of 'edksetup.sh'

o Use the bash environment variable $PWD instead of executing the pwd
  command.

o Add quotes around variables to ensure they're evaluated correctly.

o Simplify SetupPython3() and SetupPython() functions. On Linux,
  "whereis" matches python3, python3.7, as well as man pages, libs etc.
  While on macOS it only matches the specified name, and so misses
  python3.7. Improve this by looping over potential version numbers and
  seeing if such a binary exists and can be executed.

o Since when parsing options '*' matches anything not already matched,
  remove -?, -h and --help since they're redundant.

o When executing arithmetic commands, $ isn't needed before variables.

Signed-off-by: Rebecca Cran <rebecca@bsdio.com>
---
 edksetup.sh | 67 ++++++++++++++---------------------------------------
 1 file changed, 18 insertions(+), 49 deletions(-)

diff --git a/edksetup.sh b/edksetup.sh
index 12a3e26a67..a797ff03d2 100755
--- a/edksetup.sh
+++ b/edksetup.sh
@@ -49,11 +49,11 @@ function SetWorkspace()
     return 0
   fi
 
-  if [ ! ${BASH_SOURCE[0]} -ef ./edksetup.sh ] && [ -z "$PACKAGES_PATH" ]
+  if [ ! ${BASH_SOURCE[0]} -ef ./$SCRIPTNAME ] && [ -z "$PACKAGES_PATH" ]
   then
     echo Run this script from the base of your tree.  For example:
-    echo "  cd /Path/To/Edk/Root"
-    echo "  . edksetup.sh"
+    echo "  cd /path/to/edk2/root"
+    echo "  . $SCRIPTNAME"
     return 1
   fi
 
@@ -71,7 +71,7 @@ function SetWorkspace()
   #
   # Set $WORKSPACE
   #
-  export WORKSPACE=`pwd`
+  export WORKSPACE=$PWD
   return 0
 }
 
@@ -107,24 +107,10 @@ function SetupEnv()
 
 function SetupPython3()
 {
-  if [ $origin_version ];then
-    origin_version=
-  fi
-  for python in $(whereis python3)
-  do
-    python=$(echo $python | grep "[[:digit:]]$" || true)
-    python_version=${python##*python}
-    if [ -z "${python_version}" ] || (! command -v $python >/dev/null 2>&1);then
-      continue
-    fi
-    if [ -z $origin_version ];then
-      origin_version=$python_version
-      export PYTHON_COMMAND=$python
-      continue
-    fi
-      if [[ "$origin_version" < "$python_version" ]]; then
-      origin_version=$python_version
-      export PYTHON_COMMAND=$python
+  for python in $(seq -f "python3.%g" 15 -1 1) python3; do
+    if command -v $python >/dev/null 2>&1; then
+      export PYTHON_COMMAND=$(which $python)
+      break
     fi
   done
   return 0
@@ -132,8 +118,8 @@ function SetupPython3()
 
 function SetupPython()
 {
-  if [ $PYTHON_COMMAND ] && [ -z $PYTHON3_ENABLE ];then
-    if ( command -v $PYTHON_COMMAND >/dev/null 2>&1 );then
+  if [ -n "$PYTHON_COMMAND" ] && [ -z "$PYTHON3_ENABLE" ]; then
+    if command -v $PYTHON_COMMAND >/dev/null 2>&1; then
       return 0
     else
       echo $PYTHON_COMMAND Cannot be used to build or execute the python tools.
@@ -141,32 +127,15 @@ function SetupPython()
     fi
   fi
 
-  if [ $PYTHON3_ENABLE ] && [ $PYTHON3_ENABLE == TRUE ]
-  then
+  if [ "$PYTHON3_ENABLE" == "TRUE" ]; then
     SetupPython3
   fi
 
-  if [ $PYTHON3_ENABLE ] && [ $PYTHON3_ENABLE != TRUE ]
-  then
-    if [ $origin_version ];then
-      origin_version=
-    fi
-    for python in $(whereis python2)
-    do
-      python=$(echo $python | grep "[[:digit:]]$" || true)
-      python_version=${python##*python}
-      if [ -z "${python_version}" ] || (! command -v $python >/dev/null 2>&1);then
-        continue
-      fi
-      if [ -z $origin_version ]
-      then
-        origin_version=$python_version
-        export PYTHON_COMMAND=$python
-        continue
-      fi
-      if [[ "$origin_version" < "$python_version" ]]; then
-        origin_version=$python_version
-        export PYTHON_COMMAND=$python
+  if [ -n "$PYTHON3_ENABLE" ] && [ "$PYTHON3_ENABLE" != "TRUE" ]; then
+    for python in $(seq -f "python2.%g" 10 -1 1) python2; do
+      if command -v $python >/dev/null 2>&1; then
+        export PYTHON_COMMAND=$(which $python)
+        break
       fi
     done
     return 0
@@ -194,12 +163,12 @@ do
       RECONFIG=TRUE
       shift
     ;;
-    -?|-h|--help|*)
+    *)
       HelpMsg
       break
     ;;
   esac
-  I=$(($I - 1))
+  I=$((I - 1))
 done
 
 if [ $I -gt 0 ]
-- 
2.22.0