| Message ID | Y7PIHqN4ic4UBOBb@gondor.apana.org.au (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | [v3] input: Read standard input byte-wise | expand |
On 03/01/2023 06:15, Herbert Xu wrote: > Your patch breaks history support since that relies on there > being a whole line in the input buffer. Does it? preadbuffer() knows to call history() with the H_APPEND flag to append a next chunk of input to what was already added to the buffer. Cheers, Harald van Dijk
On Tue, Jan 03, 2023 at 11:54:55AM +0000, Harald van Dijk wrote: > > Does it? preadbuffer() knows to call history() with the H_APPEND flag to > append a next chunk of input to what was already added to the buffer. It only uses H_APPEND once a newline has been detected and whichprompt switches over to PS2. Cheers,
On 04/01/2023 08:59, Herbert Xu wrote: > On Tue, Jan 03, 2023 at 11:54:55AM +0000, Harald van Dijk wrote: >> >> Does it? preadbuffer() knows to call history() with the H_APPEND flag to >> append a next chunk of input to what was already added to the buffer. > > It only uses H_APPEND once a newline has been detected and > whichprompt switches over to PS2. Oh yeah, that's something I'd changed in my version already in 2019 for other reasons. I missed that dash didn't do the same. There are a few separate but related bugs in the history handling, and until they are fixed, agreed that simply reading one bye at a time will make these more prominent. One is that because of what you say, the history recording for commands greater than BUFSIZ is already buggy, but unlikely to pose a problem in practice currently because normally, people don't write such long commands. Another is that the stripping of blank lines from history breaks when blank lines are significant, as in $ cat <<EOF > hello > > world > EOF hello world $ fc 1 26 q hello world Note how the blank line was lost. If there was already "something" (as the code puts it), then when more data is appended, blanks must be preserved. There may be more that I am not seeing right now. Cheers, Harald van Dijk
diff --git a/src/input.c b/src/input.c index ec075f5..43c9161 100644 --- a/src/input.c +++ b/src/input.c @@ -159,6 +159,17 @@ int pgetc(void) return __pgetc(); } +static int stdin_clear_nonblock(void) +{ + int flags = fcntl(0, F_GETFL, 0); + + if (flags >= 0) { + flags &=~ O_NONBLOCK; + flags = fcntl(0, F_SETFL, flags); + } + + return flags; +} static int preadfd(void) @@ -195,22 +206,38 @@ retry: } else #endif + if (parsefile->fd) nr = read(parsefile->fd, buf, IBUFSIZ - 1); + else { + unsigned len = IBUFSIZ - 1; + + nr = 0; + + do { + int err; + err = read(0, buf, 1); + if (err <= 0) { + if (nr) + break; + + nr = err; + if (errno != EWOULDBLOCK) + break; + if (stdin_clear_nonblock() < 0) + break; + + out2str("sh: turning off NDELAY mode\n"); + goto retry; + } + + nr++; + } while (!IS_DEFINED_SMALL && *buf++ != '\n' && --len); + } if (nr < 0) { if (errno == EINTR) goto retry; - if (parsefile->fd == 0 && errno == EWOULDBLOCK) { - int flags = fcntl(0, F_GETFL, 0); - if (flags >= 0 && flags & O_NONBLOCK) { - flags &=~ O_NONBLOCK; - if (fcntl(0, F_SETFL, flags) >= 0) { - out2str("sh: turning off NDELAY mode\n"); - goto retry; - } - } - } } return nr; } diff --git a/src/input.h b/src/input.h index 8c39f33..8830b66 100644 --- a/src/input.h +++ b/src/input.h @@ -34,6 +34,12 @@ * @(#)input.h 8.2 (Berkeley) 5/4/95 */ +#ifdef SMALL +#define IS_DEFINED_SMALL 1 +#else +#define IS_DEFINED_SMALL 0 +#endif + /* PEOF (the end of file marker) is defined in syntax.h */ enum {