1 files changed, 54 insertions, 0 deletions
diff --git a/src/examples/sumargv.c b/src/examples/sumargv.c
new file mode 100644
index 0000000..1bd6d14
--- /dev/null
+++ b/src/examples/sumargv.c
@@ -0,0 +1,54 @@
+/* klaar@ida
+    
+   A test program for the stack setup that do not rely on any (they
+   are not yet implemented!) system calls.
+ 
+   The intended pintos command line running from userprog is:
+   
+   pintos -v -k --fs-disk=2 -p ../examples/sumargv -a sumargv -- -f -q run 'sumargv'
+   
+   This invocation shall return 0. To return any other number, invoke
+   with numbers that sum to that number. 'sumargv 1000 200 4 30 will
+   result in 1234.
+   
+   Note -v (no vga) and -q (poweroff when done) may cause trouble. If
+   you have problems exiting pintos, pres C-a and then x. If the
+   program does not seem to work it may be due to -q do poweroff too
+   fast (process_wait is incorrect).
+ */
+#include <stdlib.h>
+
+int
+main (int argc, char **argv)
+{
+  int i;
+  int sum = 0;
+  char* argv_me = "sumargv";
+  char* p;
+
+  /* If we do not have a valid `argv', exit with error code 111. */
+  if (argv == 0)
+    return 111;
+  
+  /* Weighted sum of characters in "sumargv". */
+  for (p = argv_me, i = 0; *p; ++p, ++i)
+    sum += (*p - 'a') * i;
+  
+  /* Weighted sum of characters in `argv[0]'. */
+  for (p = argv[0], i = 0; *p; ++p, ++i)
+    sum -= (*p - 'a') * i;
+  
+  /* The `sum' should now be zero if the program name `argv[0]' is
+   * correctly set up. */
+  
+  /* Interpret all remaining command line words as numbers and sum them. */
+  for (i = 1; i < argc; i++)
+    sum += atoi(argv[i]);
+  
+  /* If `argv' ends correctly with a null pointer this has no effect. */
+  sum += (int)argv[argc];
+
+  /* The final return value should now be the sum of the numbers
+   * specified after sumargv on the command line. */
+  return sum;
+}