diff options
| author | Denys Vlasenko <vda.linux@googlemail.com> | 2012-01-15 22:58:06 +0100 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2012-01-15 22:58:06 +0100 |
| commit | 7ce209b9d4f6053b7e6d07dec66e382bc3614c35 (patch) | |
| tree | 5e4aaaf494f771b61707bc12df849c01ad9e37c0 | |
| parent | d29ae7e071a11c51436922654c2de73a8ac36333 (diff) | |
| download | busybox-7ce209b9d4f6053b7e6d07dec66e382bc3614c35.tar.gz | |
shell_builtin_read: set cc[VMIN] to 1; lineedit: don't clear c_cc[VINTR]
First change fixes "read -n NUM". Apparently poll() won't report
data availability if cc[VMIN] > 1 until there are at least cc[VMIN] bytes.
function old new delta
read_line_input 3885 3877 -8
shell_builtin_read 1097 1087 -10
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-18) Total: -18 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | libbb/lineedit.c | 15 | ||||
| -rw-r--r-- | shell/shell_common.c | 8 |
2 files changed, 16 insertions, 7 deletions
diff --git a/libbb/lineedit.c b/libbb/lineedit.c index 1390ed62d..460e27fed 100644 --- a/libbb/lineedit.c +++ b/libbb/lineedit.c @@ -2206,14 +2206,17 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman #define command command_must_not_be_used new_settings = initial_settings; - new_settings.c_lflag &= ~ICANON; /* unbuffered input */ - /* Turn off echoing and CTRL-C, so we can trap it */ - new_settings.c_lflag &= ~(ECHO | ECHONL | ISIG); - /* Hmm, in linux c_cc[] is not parsed if ICANON is off */ + /* ~ICANON: unbuffered input (most c_cc[] are disabled, VMIN/VTIME are enabled) */ + /* ~ECHO, ~ECHONL: turn off echoing, including newline echoing */ + /* ~ISIG: turn off INTR (ctrl-C), QUIT, SUSP */ + new_settings.c_lflag &= ~(ICANON | ECHO | ECHONL | ISIG); + /* reads would block only if < 1 char is available */ new_settings.c_cc[VMIN] = 1; + /* no timeout (reads block forever) */ new_settings.c_cc[VTIME] = 0; - /* Turn off CTRL-C, so we can trap it */ - new_settings.c_cc[VINTR] = _POSIX_VDISABLE; + /* Should be not needed if ISIG is off: */ + /* Turn off CTRL-C */ + /* new_settings.c_cc[VINTR] = _POSIX_VDISABLE; */ tcsetattr_stdin_TCSANOW(&new_settings); #if ENABLE_USERNAME_OR_HOMEDIR diff --git a/shell/shell_common.c b/shell/shell_common.c index bbc22ed34..51c92d60e 100644 --- a/shell/shell_common.c +++ b/shell/shell_common.c @@ -138,7 +138,13 @@ shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val), old_tty = tty; if (nchars) { tty.c_lflag &= ~ICANON; - tty.c_cc[VMIN] = nchars < 256 ? nchars : 255; + // Setting it to more than 1 breaks poll(): + // it blocks even if there's data. !?? + //tty.c_cc[VMIN] = nchars < 256 ? nchars : 255; + /* reads would block only if < 1 char is available */ + tty.c_cc[VMIN] = 1; + /* no timeout (reads block forever) */ + tty.c_cc[VTIME] = 0; } if (read_flags & BUILTIN_READ_SILENT) { tty.c_lflag &= ~(ECHO | ECHOK | ECHONL); |