Make main() in pt-stalk.

bin/pt-stalk

@@ -99,6 +99,9 @@ log() {
    echo "${1}" >&2
 }
 
+# The main code that runs by default.  Arguments are the command-line options.
+main() {
+
    # Make the collection location
    mkdir -p "${DEST}" || die "Can't make the destination directory"
    test -d "${DEST}"  || die "${DEST} isn't a directory"
@@ -109,8 +112,8 @@ if [ "$(id -u)" != "0" ]; then
       echo 'Not running with root privileges!';
    fi
 
-# We increment this variable every time that the check is true, and set it to 0
-# if it's false.
+   # We increment this variable every time that the check is true,
+   # and set it to 0 if it's false.
    cycles_true=0;
 
    while true; do
@@ -158,6 +161,13 @@ while true; do
          -depth -mtime +${PURGE} -exec rm -f '{}' \;
 
    done
+}
+
+# Execute the program if it was not included from another file.
+# This makes it possible to include without executing, and thus test.
+if [ "$(basename "$0")" = "pt-stalk" ] || [ "$(basename "$0")" = "bash" -a "$_" = "$0" ]; then
+   main "$@"
+fi
 
 # ############################################################################
 # Documentation