From 0eda390d68c456975289471e68b615ae096ab33b Mon Sep 17 00:00:00 2001
From: Ron Yorston <rmy@pobox.com>
Date: Fri, 8 Feb 2019 09:54:21 +0000
Subject: ash: improve handling of 'read -t 0'
Instead of always returning that no input is available:
- for a disk file return 'available';
- for the console return 'not available';
- for anything else (e.g. pipe) return whatever poll says.
This fixes the test ash-read/read_t0.tests.
---
shell/shell_common.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
(limited to 'shell')
diff --git a/shell/shell_common.c b/shell/shell_common.c
index e7c07e6a9..70ecf2095 100644
--- a/shell/shell_common.c
+++ b/shell/shell_common.c
@@ -136,20 +136,28 @@ shell_builtin_read(struct builtin_read_params *params)
}
if (params->opt_t && end_ms == 0) {
-#if !ENABLE_PLATFORM_MINGW32
/* "If timeout is 0, read returns immediately, without trying
* to read any data. The exit status is 0 if input is available
* on the specified file descriptor, non-zero otherwise."
* bash seems to ignore -p PROMPT for this use case.
*/
int r;
+#if ENABLE_PLATFORM_MINGW32
+ HANDLE handle = (HANDLE)_get_osfhandle(fd);
+ DWORD filetype = FILE_TYPE_UNKNOWN;
+
+ if (handle != INVALID_HANDLE_VALUE)
+ filetype = GetFileType(handle);
+ /* poll uses WaitForSingleObject which can't handle disk files */
+ if (filetype == FILE_TYPE_DISK || filetype == FILE_TYPE_UNKNOWN)
+ return (const char *)(uintptr_t)(0);
+ if (isatty(fd))
+ return (const char *)(uintptr_t)(1);
+#endif
pfd[0].events = POLLIN;
r = poll(pfd, 1, /*timeout:*/ 0);
/* Return 0 only if poll returns 1 ("one fd ready"), else return 1: */
return (const char *)(uintptr_t)(r <= 0);
-#else
- return (const char *)(uintptr_t)(1);
-#endif
}
if (params->opt_p && isatty(fd)) {
--
cgit v1.2.3-55-g6feb