fix: printHash.sh; replace echo -n, check if $1 is set.

printHash.sh

@@ -1,12 +1,14 @@
-#!/usr/bin/env bash
-
-> $1
-
-echo -n "#define GIT_SHA1 \"" > $1
-
-if (command -v "git" >/dev/null) then
-git rev-parse --short HEAD | tr -d '\n' >> $1
+#!/usr/bin/env sh
+if [ -z "${1}" ]
+ then
+  printf "%s\n" "Input the path to the file for writing the commit hash to."
+ else
+  printf "%s" "#define GIT_SHA1 \"" > $1
+
+  if (command -v "git" >/dev/null) then
+   git rev-parse --short HEAD | tr -d '\n' >> $1
+  fi
+
+  printf "%s\n" "\"" >> $1
+  printf "%s\n" "const char* g_GIT_SHA1 = GIT_SHA1;" >> $1
 fi
-
-echo "\"" >> $1
-echo "const char* g_GIT_SHA1 = GIT_SHA1;" >> $1