diff --git a/TODO b/TODO
new file mode 100644
index 0000000..79305b8
--- /dev/null
+++ b/TODO
@@ -0,0 +1,31 @@
+cksum [file...]
+
+cmp [-ls] file1 file2
+
+comm [-123] file1 file2
+
+cp [-r] file [name]
+cp [-r] [file...] [directory]
+
+cut [-bcfs] [-d delim] list [file...]
+
+diff [-ru] file1 file2
+
+fold [-bs] [-w width] [file...]
+
+id [-gnru] [user]
+
+kill [-s signal] [pid...]
+
+mv file [name]
+mv [file...] directory
+
+nohup command [argument...]
+
+paste [-s] [-d list] [file...]
+
+printf format [argument...]
+
+test [expression...]
+
+tr string1 [string2]
diff --git a/config.mk b/config.mk
index 56778fa..21080f7 100644
--- a/config.mk
+++ b/config.mk
@@ -3,7 +3,7 @@ VERSION = 0.0
 
 # paths
 PREFIX = /usr/local
-MANPREFIX = ${PREFIX}/share/man
+MANPREFIX = $(PREFIX)/share/man
 
 #CC = gcc
 #CC = musl-gcc