[Libguestfs] [PATCH] Add echo_daemon command

[Matthew Booth]

On 11/09/09 15:51, Richard W.M. Jones wrote:
> On Fri, Sep 11, 2009 at 02:39:24PM +0100, Matthew Booth wrote:
>> +    /* Make the output buffer big enough for the string and its terminator */
>> +    out = realloc (out, out_len + 1);
>
> In the daemon we have to check the return value from malloc/realloc
> very carefully.  The reason is that the daemon runs in limited space.

Good catch.

>> +    /* Prepend a space if required */
>> +    if (add_space) {
>> +      out[out_end++] = ' ';
>> +    }
>> +
>> +    /* Copy the argument to the output */
>> +    memcpy(&out[out_end], *argv, arg_len);
>> +
>> +    argv++;
>> +  }
>> +
>> +  /* NULL terminate the output */
>> +  out[out_len] = '\0';
>> +
>> +  return out;
>> +}
>> diff --git a/po/POTFILES.in b/po/POTFILES.in
>> index 1b2f82a..44e472b 100644
>> --- a/po/POTFILES.in
>> +++ b/po/POTFILES.in
>> @@ -12,6 +12,7 @@ daemon/dir.c
>>   daemon/dmesg.c
>>   daemon/dropcaches.c
>>   daemon/du.c
>> +daemon/echo_daemon.c
>>   daemon/ext2.c
>>   daemon/fallocate.c
>>   daemon/file.c
>> diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
>> index 205a12b..6bb2f98 100644
>> --- a/src/MAX_PROC_NR
>> +++ b/src/MAX_PROC_NR
>> @@ -1 +1 @@
>> -194
>> +195
>> diff --git a/src/generator.ml b/src/generator.ml
>> index 439c9c4..f820e1f 100755
>> --- a/src/generator.ml
>> +++ b/src/generator.ml
>> @@ -3595,6 +3595,13 @@ This loads a kernel module in the appliance.
>>   The kernel module must have been whitelisted when libguestfs
>>   was built (see C<appliance/kmod.whitelist.in>  in the source).");
>>
>> +  ("echo_daemon", (RString "output", [StringList "words"]), 195, [],
>> +   [InitNone, Always, TestRun [["echo_daemon"; "\"This is a test\""]]],
>
> This should test the return value using TestOutput.  Also note that
> this is passing a list of length four.  (Handling of lists in the test
> code is very hairy).

Ok.

>> +   "echo arguments back to the client",
>> +   "\
>> +This commands works much like the unix echo command. It returns its arguments as
>> +a string.");
>
> A better description:
>
>    This command concatenates the list of C<words>  passed with
>    single spaces between them and returns the resulting string.
>
>    You can use this to test the connection through to the daemon.
>
>    See also C<guestfs_ping_daemon>.

Ok. Updated patch to follow.

Matt
-- 
Matthew Booth, RHCA, RHCSS
Red Hat Engineering, Virtualisation Team

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