Libguestfs - May 2014 - Re: [PATCH] test-charset-fidelity: allow to skip testing specific FSes

Allow to skip testing the filesystem "foo" if the environment variable
SKIP_TEST_CHARSET_FIDELITY_foo=1 is set. This way it possible to not
test one or more filesystems without disabling the test altogether.
---
 tests/charsets/test-charset-fidelity.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/tests/charsets/test-charset-fidelity.c
b/tests/charsets/test-charset-fidelity.c
index c669b9d..654ea0f 100644
--- a/tests/charsets/test-charset-fidelity.c
+++ b/tests/charsets/test-charset-fidelity.c
@@ -33,6 +33,8 @@
 #include "guestfs.h"
 #include "guestfs-internal-frontend.h"
 
+static const char ourenvvar[] = "SKIP_TEST_CHARSET_FIDELITY";
+
 struct filesystem {
   const char *fs_name;          /* Name of filesystem. */
   int fs_case_insensitive;      /* True if filesystem is case insensitive. */
@@ -78,7 +80,7 @@ main (int argc, char *argv[])
   struct filesystem *fs;
 
   /* Allow this test to be skipped. */
-  str = getenv ("SKIP_TEST_CHARSET_FIDELITY");
+  str = getenv (ourenvvar);
   if (str && STREQ (str, "1")) {
     printf ("%s: test skipped because environment variable is
set.\n",
             program_name);
@@ -113,6 +115,8 @@ static void
 test_filesystem (guestfs_h *g, const struct filesystem *fs)
 {
   const char *feature[] = { fs->fs_feature, NULL };
+  char envvar[sizeof (ourenvvar) + 20];
+  char *str;
 
   if (fs->fs_feature && !guestfs_feature_available (g, (char **)
feature)) {
     printf ("skipped test of %s because %s feature not available\n",
@@ -120,6 +124,14 @@ test_filesystem (guestfs_h *g, const struct filesystem *fs)
     return;
   }
 
+  snprintf (envvar, sizeof (envvar) - 1, "%s_%s", ourenvvar,
fs->fs_name);
+  str = getenv (envvar);
+  if (str && STREQ (str, "1")) {
+    printf ("skipped test of %s because environment variable is
set\n",
+            fs->fs_name);
+    return;
+  }
+
   printf ("testing charset fidelity on %s\n", fs->fs_name);
 
   make_filesystem (g, fs);
-- 
1.9.0

On Mon, May 05, 2014 at 05:05:29PM +0200, Pino Toscano
wrote:
> +  snprintf (envvar, sizeof (envvar) - 1, "%s_%s", ourenvvar,
fs->fs_name);
Is this right?

I'm tempted to say it should be `sizeof envvar'.  However my knowledge
of C is not clear enough to say whether that would evaluate to the
size of the array or the size of a pointer (8 bytes).

So perhaps it's safer to use something like:

  const size_t len = /* computed size */;
  const char envvar[len];
  /*  ... */
  snprintf (envvar, len, ...);

Rich.

-- 
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On Wednesday 07 May 2014 10:05:56 Richard W.M. Jones
wrote:
> On Mon, May 05, 2014 at 05:05:29PM +0200, Pino Toscano wrote:
> > +  snprintf (envvar, sizeof (envvar) - 1, "%s_%s",
ourenvvar,
> > fs->fs_name);
> Is this right?
> 
> I'm tempted to say it should be `sizeof envvar'.  However my
knowledge
> of C is not clear enough to say whether that would evaluate to the
> size of the array or the size of a pointer (8 bytes).
Yes, this works because envvar is a char array. (Theoretically it should 
be sizeof(buf)/sizeof(buf[0]), but since sizeof(char) == 1 usually then 
could be omitted.)

The "- 1" bit is because I always forget whether the size argument in 
the {,v}snprint functions include the \0 at the end. There is enough 
space in this case anyway, so it shouldn't matter that much.

-- 
Pino Toscano