On Mon, Jan 23, 2017 at 04:29:00PM -0600, Eric Sandeen wrote:
> On 1/20/17 2:25 PM, Darrick J. Wong wrote:
> > The 'source' command is supposed to read commands out of a file and
> > execute them. This works great when done from an interactive command
> > line, but it doesn't work at all when invoked from the command line
> > because we never actually do anything with the opened file.
> >
> > So don't load stdin into the input stack when we're only executing
> > command line options, and use that to decide if source_f is executing
> > from the command line so that we can actually run the input loop. We'll
> > use this for the per-field fuzzing xfstests.
> >
> > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> > ---
> > db/init.c | 2 +-
> > db/input.c | 29 +++++++++++++++++++++++++++--
> > 2 files changed, 28 insertions(+), 3 deletions(-)
> >
> >
> > diff --git a/db/init.c b/db/init.c
> > index e60ac66..46af024 100644
> > --- a/db/init.c
> > +++ b/db/init.c
> > @@ -254,7 +254,6 @@ main(
> > char **v;
> > int start_iocur_sp;
> >
> > - pushfile(stdin);
> > init(argc, argv);
> > start_iocur_sp = iocur_sp;
> >
> > @@ -269,6 +268,7 @@ main(
> > goto close_devices;
> > }
>
> Ok, so anything above this is commandline invocations.
>
> Everything below is interactive...
>
> > + pushfile(stdin);
> > while (!done) {
> > if ((input = fetchline()) == NULL)
> > break;
> > diff --git a/db/input.c b/db/input.c
> > index 8f65190..7b12c97 100644
> > --- a/db/input.c
> > +++ b/db/input.c
> > @@ -145,6 +145,12 @@ get_prompt(void)
> > return prompt;
> > }
> >
> > +static bool
> > +interactive_input(void)
> > +{
> > + return inputstacksize == 1 && inputstack[0] == stdin;
> > +}
>
> how about just:
>
> return curinput == stdin?
Sure.
> > +
> > static char *
> > fetchline_internal(void)
> > {
> > @@ -156,7 +162,9 @@ fetchline_internal(void)
> >
> > rval = NULL;
> > for (rlen = iscont = 0; ; ) {
> > - if (inputstacksize == 1) {
> > + if (curinput == NULL)
> > + return NULL;
> > + if (interactive_input()) {
> > if (iscont)
> > dbprintf("... ");
> > else
> > @@ -183,7 +191,8 @@ fetchline_internal(void)
> > (len = strlen(buf)) == 0) {
> > popfile();
> > if (curinput == NULL) {
> > - dbprintf("\n");
> > + if (interactive_input())
> > + dbprintf("\n");
>
> I give up. I see from testing that it is, but why is \n special here?
When we have an interactive session, no libreadline, and the user hits
^D, this makes it so that we print a newline before the prompt returns
so that we don't end up with:
xfs_db> bash-2.05$
However, now that we've moved pushfile(stdin), it's possible that a
non-interactive session (which is what you get with "-c 'source moo'")
will pop all the fds off the stack, causing the newline to print.
A better fix for all this is to:
if (curinput == stdin)
dbprintf("\n");
popfile();
iscont = 0...
Another odd quirk I noticed is that when an invocation of
fetchline_internal reaches feof/ferror on a file descriptor, it'll pop
the input stack and try to continue with the next lower level. Since
each source_f starts its own interpreter loop we could just jump out
when we run out of input data and let the /caller/ continue with the fd
that it pushed onto the stack.
>
> > return NULL;
> > }
> > iscont = 0;
> > @@ -314,12 +323,28 @@ source_f(
> > char **argv)
> > {
> > FILE *f;
> > + int c, done = 0;
> > + char *input;
> > + char **v;
> >
> > f = fopen(argv[1], "r");
> > if (f == NULL)
> > dbprintf(_("can't open %s\n"), argv[0]);
> > else
> > pushfile(f);
> > +
> > + /* If this isn't an interactive shell, run the commands now. */
> > + if (inputstacksize == 0 || inputstack[0] == stdin)
>
> This confuses me a bit, partly from the comment. We could be in
> an interactive shell, but we've just issued a source command ...
>
> If inputstacksize == 0, that means fopen failed and we didn't
> do a pushfile, right? Maybe best to just return in the failure
> case above, and skip that test here?
>
> And how can we ever be here w/ inputstack[0] == stdin?
>
> I'm wondering if this isn't cleaner and still correct:
>
> f = fopen(argv[1], "r");
> if (f == NULL) {
> dbprintf(_("can't open %s\n"), argv[0]);
> return 0;
> }
>
> /* Run the sourced commands now */
> pushfile(f);
> while (!done) {
> if ((input = fetchline_internal()) == NULL)
Yes, that does seem cleaner.
--D
>
> > + return 0;
> > + while (!done) {
> > + if ((input = fetchline_internal()) == NULL)
> > + break;
> > + v = breakline(input, &c);
> > + if (c)
> > + done = command(c, v);
> > + doneline(input, v);
> > + }
> > +
> > return 0;
> > }
> >
> >
> > --
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