Re: [Libguestfs] [PATCH] Add echo_daemon command

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.

> + /* 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).

> + "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>.