From 3f6e372a29709225f53f4d326170af1aeecb2cf5 Mon Sep 17 00:00:00 2001
From: Frans Kaashoek <kaashoek@mit.edu>
Date: Thu, 19 Sep 2019 15:14:52 -0400
Subject: [PATCH] make exec test self contained

---
 user/usertests.c | 73 ++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 62 insertions(+), 11 deletions(-)

diff --git a/user/usertests.c b/user/usertests.c
index d965077..6fd8c29 100644
--- a/user/usertests.c
+++ b/user/usertests.c
@@ -21,7 +21,6 @@
 
 char buf[BUFSZ];
 char name[3];
-char *echoargv[] = { "echo", "ALL", "TESTS", "PASSED", 0 };
 
 // does chdir() call iput(p->cwd) in a transaction?
 void
@@ -283,10 +282,56 @@ void dirtest(char *s)
 void
 exectest(char *s)
 {
-  if(exec("echo", echoargv) < 0){
-    printf("%s: exec echo failed\n", s);
+  int fd, xstatus, pid;
+  char *echoargv[] = { "echo", "OK", 0 };
+  char buf[3];
+
+  unlink("echo-ok");
+  pid = fork();
+  if(pid < 0) {
+     printf("%s: fork failed\n", s);
+     exit(1);
+  }
+  if(pid == 0) {
+    close(1);
+    fd = open("echo-ok", O_CREATE|O_WRONLY);
+    if(fd < 0) {
+      printf("%s: create failed\n", s);
+      exit(1);
+    }
+    if(fd != 1) {
+      printf("%s: wrong fd\n", s);
+      exit(1);
+    }
+    if(exec("echo", echoargv) < 0){
+      printf("%s: exec echo failed\n", s);
+      exit(1);
+    }
+    // won't get to here
+  }
+  if (wait(&xstatus) != pid) {
+    printf("%s: wait failed!\n", s);
+  }
+  if(xstatus != 0)
+    exit(xstatus);
+
+  fd = open("echo-ok", O_RDONLY);
+  if(fd < 0) {
+    printf("%s: open failed\n", s);
     exit(1);
   }
+  if (read(fd, buf, 2) != 2) {
+    printf("%s: read failed\n", s);
+    exit(1);
+  }
+  unlink("echo-ok");
+  if(buf[0] == 'O' && buf[1] == 'K')
+    exit(0);
+  else {
+    printf("%s: wrong output\n", s);
+    exit(1);
+  }
+
 }
 
 // simple fork and pipe read/write
@@ -1862,7 +1907,8 @@ stacktest(char *s)
     exit(xstatus);
 }
 
-void
+// 1 if successful
+int
 run(void f(char *), char *s) {
   int pid;
   int xstatus;
@@ -1876,12 +1922,12 @@ run(void f(char *), char *s) {
     exit(0);
   } else {
     wait(&xstatus);
-    if(xstatus != 0)
+    if(xstatus != 0) 
       printf("test %s FAILED\n", s);
     else
       printf("test %s OK\n", s);
+    return xstatus == 0;
   }
-  
 }
 
 int
@@ -1909,6 +1955,7 @@ main(int argc, char *argv[])
     {subdir, "subdir"},
     {fourfiles, "fourfiles"},
     {sharedfd, "sharedfd"},
+    {exectest, "exectest"},
     {bigargtest, "bigargtest"},
     {bigwrite, "bigwrite"},
     {bsstest, "bsstest"},
@@ -1933,23 +1980,27 @@ main(int argc, char *argv[])
     {iref, "iref"},
     {forktest, "forktest"},
     {bigdir, "bigdir"}, // slow
-    {exectest, "exectest"},  // must be last
     { 0, 0},
   };
     
   printf("usertests starting\n");
 
   if(open("usertests.ran", 0) >= 0){
-    printf("already ran user tests -- rebuild fs.img\n");
+    printf("already ran user tests -- rebuild fs.img (make fs.img)\n");
     exit(1);
   }
   close(open("usertests.ran", O_CREATE));
 
+  int fail = 0;
   for (struct test *t = tests; t->s != 0; t++) {
     if((n == 0) || strcmp(t->s, n) == 0) {
-      run(t->f, t->s);
+      if(!run(t->f, t->s))
+        fail = 1;
     }
   }
-
-  exit(0);
+  if(!fail)
+    printf("ALL TESTS PASSED\n");
+  else
+    printf("SOME TESTS FAILED\n");
+  exit(1);   // not reached.
 }