2010/12/7 Eric Blake <ebl...@redhat.com>: > Guarantee that outbuf/errbuf are allocated on success, even if to the > empty string. Caller always has to free the result, and empty output > check requires checking if *outbuf=='\0'. Makes the API easier to use > safely. Failure is best effort allocation (some paths, like > out-of-memory, cannot allocate a buffer, but most do), so caller must > free buffer on failure; but this now guarantees that VIR_FREE(buf) > will be safe. > > * docs/internals/command.html.in: Update documentation. > * src/util/command.c (virCommandSetOutputBuffer) > (virCommandSetErrorBuffer, virCommandProcessIO) Guarantee empty > string on no output. > * tests/commandtest.c (test17): New test. > --- > > Everyone liked the safety of v2 over the speed of v1; and in looking > at it more, I found even more ways to make it safer. Hence this v3. > > docs/internals/command.html.in | 12 ++++++-- > src/util/command.c | 53 ++++++++++++++++++++++++++++-------- > tests/commandtest.c | 58 > ++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 108 insertions(+), 15 deletions(-)
> diff --git a/tests/commandtest.c b/tests/commandtest.c > index b7261e9..20e56bc 100644 > --- a/tests/commandtest.c > +++ b/tests/commandtest.c > @@ -595,6 +595,63 @@ cleanup: > return ret; > } > > +/* > + * Test string handling when no output is present. > + */ > +static int test17(const void *unused ATTRIBUTE_UNUSED) > +{ > + virCommandPtr cmd = virCommandNew("/bin/true"); > + int ret = -1; > + char *outbuf; > + char *errbuf; > + > + virCommandSetOutputBuffer(cmd, &outbuf); > + if (outbuf != NULL) { > + puts("buffer not sanitized at registration"); > + goto cleanup; > + } > + > + if (virCommandRun(cmd, NULL) < 0) { > + virErrorPtr err = virGetLastError(); > + printf("Cannot run child %s\n", err->message); > + goto cleanup; > + } > + > + if (!outbuf || *outbuf) { > + puts("output string not allocated"); The error message doesn't fit to the *outbuf != \0 test. > + goto cleanup; > + } > + VIR_FREE(outbuf); > + if ((outbuf = strdup("should not be leaked")) == NULL) { > + puts("test framework failure"); > + goto cleanup; > + } > + > + virCommandSetErrorBuffer(cmd, &errbuf); > + if (errbuf != NULL) { > + puts("buffer not sanitized at registration"); > + goto cleanup; > + } > + > + if (virCommandRun(cmd, NULL) < 0) { > + virErrorPtr err = virGetLastError(); > + printf("Cannot run child %s\n", err->message); > + goto cleanup; > + } > + > + if (!outbuf || *outbuf || !errbuf || *errbuf) { > + puts("output strings not allocated"); The error message doesn't fit to the *{out|err}buf != \0 test. Also what about the case when running /bin/true prints to {std|err}out for some reason? :) ACK. Matthias -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list