tools/read-dependencies, read-version: cleanups, and use sed not grep

There are just some cleanups here, and use of simply 'sed' rather than
grep and cut.  The motivation is to support running with non gnu 
'grep' that doesn't have -P.

1 files changed, 8 insertions, 8 deletions

diff --git a/tools/read-version b/tools/read-version
index c76b24a9..c37228f8 100755
--- a/tools/read-version
+++ b/tools/read-version
@@ -12,20 +12,20 @@ find_root() {
    [ $? -eq 0 -a -f "${topd}/setup.py" ] || return
    ROOT_DIR="$topd"
 }
+fail() { echo "$0:" "$@" 1>&2; exit 1; }
 
 if ! find_root; then
-    echo "Unable to locate 'setup.py' file that should" \
-          "exist in the cloud-init root directory." 1>&2
-    exit 1;
+    fail "Unable to locate 'setup.py' file that should " \
+         "exist in the cloud-init root directory."
 fi
 
 CHNG_LOG="$ROOT_DIR/ChangeLog"
 
-if [ ! -e "$CHNG_LOG" ]
-then
-    echo "Unable to find 'ChangeLog' file located at $CHNG_LOG"
-    exit 1
+if [ ! -e "$CHNG_LOG" ]; then
+    fail "Unable to find 'ChangeLog' file located at '$CHNG_LOG'"
 fi
 
-VERSION=$(grep -P "\d+.\d+.\d+:" "$CHNG_LOG"  | cut -f1 -d ":" | head -n 1)
+VERSION=$(sed -n '/^[0-9]\+[.][0-9]\+[.][0-9]\+:/ {s/://; p; :a;n; ba}' \
+          "$CHNG_LOG") ||
+   fail "failed to get version from '$CHNG_LOG'"
 echo "$VERSION"