progname: also set global program_invocation_name, when possible.

[gnulib.git] / tests / test-pipe.c

diff --git a/tests/test-pipe.c b/tests/test-pipe.c
index c542509..404534d 100644 (file)
--- a/tests/test-pipe.c
+++ b/tests/test-pipe.c
@@ -21,22 +21,27 @@
 #include "wait-process.h"
 
 #include <errno.h>
-#include <fcntl.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
 /* Depending on arguments, this test intentionally closes stderr or
-   starts life with stderr closed.  So, the error messages might not
-   always print, but at least the exit status will be reliable.  */
+   starts life with stderr closed.  So, we arrange to have fd 10
+   (outside the range of interesting fd's during the test) set up to
+   duplicate the original stderr.  */
+
+#define BACKUP_STDERR_FILENO 10
+static FILE *myerr;
+
 #define ASSERT(expr) \
   do                                                                         \
     {                                                                        \
       if (!(expr))                                                           \
         {                                                                    \
-          fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
-          fflush (stderr);                                                   \
+          fprintf (myerr, "%s:%d: assertion failed\n", __FILE__, __LINE__);  \
+          fflush (myerr);                                                    \
           abort ();                                                          \
         }                                                                    \
     }                                                                        \
@@ -46,9 +51,9 @@
 static int
 child_main (int argc, char *argv[])
 {
-  char buffer[1];
-  int i;
+  char buffer[2] = { 's', 't' };
   int fd;
+  int ret;
 
   ASSERT (argc == 3);
 
@@ -56,29 +61,22 @@ child_main (int argc, char *argv[])
      fd 2 should be closed iff the argument is 1.  Check that no other file
      descriptors leaked.  */
 
-  ASSERT (read (STDIN_FILENO, buffer, 1) == 1);
+  ASSERT (read (STDIN_FILENO, buffer, 2) == 1);
 
   buffer[0]++;
   ASSERT (write (STDOUT_FILENO, buffer, 1) == 1);
 
   errno = 0;
-#ifdef F_GETFL
-  /* Try to keep stderr open for better diagnostics.  */
-  i = fcntl (STDERR_FILENO, F_GETFL);
-#else
-  /* But allow compilation on mingw.  You might need to disable this code for
-     debugging failures.  */
-  i = close (STDERR_FILENO);
-#endif
+  ret = dup2 (STDERR_FILENO, STDERR_FILENO);
   switch (atoi (argv[2]))
     {
     case 0:
-      /* Expect fd 2 was open.  */
-      ASSERT (i >= 0);
+      /* Expect fd 2 is open.  */
+      ASSERT (ret == STDERR_FILENO);
       break;
     case 1:
-      /* Expect fd 2 was closed.  */
-      ASSERT (i < 0);
+      /* Expect fd 2 is closed.  */
+      ASSERT (ret == -1);
       ASSERT (errno == EBADF);
       break;
     default:
@@ -119,6 +117,7 @@ test_pipe (const char *argv0, bool stderr_closed)
 
   /* Push child's input.  */
   ASSERT (write (fd[1], buffer, 1) == 1);
+  ASSERT (close (fd[1]) == 0);
 
   /* Get child's output.  */
   ASSERT (read (fd[0], buffer, 2) == 1);
@@ -126,7 +125,6 @@ test_pipe (const char *argv0, bool stderr_closed)
   /* Wait for child.  */
   ASSERT (wait_subprocess (pid, argv0, true, false, true, true, NULL) == 0);
   ASSERT (close (fd[0]) == 0);
-  ASSERT (close (fd[1]) == 0);
 
   /* Check the result.  */
   ASSERT (buffer[0] == 'b');
@@ -193,9 +191,23 @@ parent_main (int argc, char *argv[])
 int
 main (int argc, char *argv[])
 {
-  ASSERT (argc >= 2);
+  if (argc < 2)
+    {
+      fprintf (stderr, "%s: need arguments\n", argv[0]);
+      return 2;
+    }
   if (strcmp (argv[1], "child") == 0)
-    return child_main (argc, argv);
-  else
-    return parent_main (argc, argv);
+    {
+      /* fd 2 might be closed, but fd BACKUP_STDERR_FILENO is the original
+        stderr.  */
+      myerr = fdopen (BACKUP_STDERR_FILENO, "w");
+      if (!myerr)
+       return 2;
+      return child_main (argc, argv);
+    }
+  /* We might close fd 2 later, so save it in fd 10.  */
+  if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
+      || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
+    return 2;
+  return parent_main (argc, argv);
 }