Documentation!

pwd.c

@@ -5,7 +5,15 @@
 #include <stdlib.h>
 
 int main(int argc, char * argv[]) {
-  int mode = 01; /* 01: print PWD -L, 02: print physical path -P */
+  /* 
+    The -L option prints the logical path, corresponding to the PWD envar.
+    -P prints the physical path. The logical path includes any symbolic
+    links followed to get there, where as the physical path doesn't. So,
+    for example, if /lib links to /usr/lib, then if we cd /lib, pwd -L will
+    print /lib, whereas pwd -P will print /usr/lib, even though cd .. will
+    take us back to /
+  */
+  int mode = 01; /* 01: -L, 02: -P */
   char c;
 
   while((c = getopt(argc, argv, "LP")) != -1) {