On 11/23/2010 04:49 PM, Eric Blake wrote:
From: Daniel P. Berrange <berrange@redhat.com>
This introduces a new set of APIs in src/util/command.h to use for invoking commands. This is intended to replace all current usage of virRun and virExec variants, with a more flexible and less error prone API.
+/* + * Call after adding all arguments and environment settings, but before + * Run/RunAsync, to immediately output the environment and arguments of + * cmd to logfd. If virCommandRun cannot succeed (because of an + * out-of-memory condition while building cmd), nothing will be logged. + */ +void virCommandWriteArgLog(virCommandPtr cmd, + int logfd); + +/* + * Call after adding all arguments and environment settings, but before + * Run/RunAsync, to return a string representation of the environment and + * arguments of cmd. If virCommandRun cannot succeed (because of an + * out-of-memory condition while building cmd), NULL will be returned. + * Caller is responsible for freeing the resulting string. + */ +char *virCommandToString(virCommandPtr cmd) ATTRIBUTE_RETURN_CHECK;
Bummer. Just realized that these functions should probably be modified to take another parameter that controls whether the output should be quoted for shell use. Basically, I just tested the recent addition of <smbios mode='host'/>, and found out that it has a bug: it takes the host string (which may have spaces), and passes it to the qemu command line as: -smbios 'type=0,version="6FET82WW (3.12 )"' which means that the guest gets literal "" in the SMBIOS string, whereas the host did not have them, such that it is not a true host mirroring as intended. But in the /var/log/libvirt/qemu/...log, the argument only shows up as: -smbios type=0,version="6FET82WW (3.12 )" which, when pasted literally into a shell, does the right thing. Therefore, adding the ability to shell-quote the log will make it easier to log complex shell commands, where we really did intend to pass shell metacharacters via a single argument. I'll have to fold that in to my next revision. -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org