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Posted to commits@nuttx.apache.org by xi...@apache.org on 2020/10/13 08:05:08 UTC
[incubator-nuttx-apps] 01/01: Remove all fclose with stdin,
stdout and stderr
This is an automated email from the ASF dual-hosted git repository.
xiaoxiang pushed a commit to branch fclose
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx-apps.git
commit 772f68a16bb8f93dfc2ace380bb5c36c12dda3f9
Author: Xiang Xiao <xi...@xiaomi.com>
AuthorDate: Tue Oct 13 15:53:19 2020 +0800
Remove all fclose with stdin, stdout and stderr
since it is wrong to close the builtin stream and specially note
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fclose.html:
Since after the call to fclose() any use of stream results in
undefined behavior, fclose() should not be used on stdin, stdout,
or stderr except immediately before process termination (see XBD
Process Termination), so as to avoid triggering undefined behavior
in other standard interfaces that rely on these streams. If there
are any atexit() handlers registered by the application, such a
call to fclose() should not occur until the last handler is
finishing. Once fclose() has been used to close stdin, stdout, or
stderr, there is no standard way to reopen any of these streams.
and it is also unnecessary because the stream always get flushed.
Signed-off-by: Xiang Xiao <xi...@xiaomi.com>
---
examples/nxterm/nxterm_main.c | 3 ---
graphics/nxwm/src/cnxterm.cxx | 15 +++------------
graphics/twm4nx/apps/cnxterm.cxx | 15 +++------------
nshlib/nsh_altconsole.c | 15 ++++++---------
nshlib/nsh_usbconsole.c | 22 ++++------------------
5 files changed, 16 insertions(+), 54 deletions(-)
diff --git a/examples/nxterm/nxterm_main.c b/examples/nxterm/nxterm_main.c
index 491ee94..8c96787 100644
--- a/examples/nxterm/nxterm_main.c
+++ b/examples/nxterm/nxterm_main.c
@@ -391,9 +391,6 @@ int main(int argc, FAR char *argv[])
fflush(stdout);
fflush(stderr);
- fclose(stdout);
- fclose(stderr);
-
dup2(fd, 1);
dup2(fd, 2);
diff --git a/graphics/nxwm/src/cnxterm.cxx b/graphics/nxwm/src/cnxterm.cxx
index 8273b69..2b7716d 100644
--- a/graphics/nxwm/src/cnxterm.cxx
+++ b/graphics/nxwm/src/cnxterm.cxx
@@ -500,14 +500,11 @@ int CNxTerm::nxterm(int argc, char *argv[])
// console). (2) Don't bother trying to put debug instrumentation in the
// following because it will end up in the NxTerm window.
- std::fflush(stdout);
- std::fflush(stderr);
-
#ifdef CONFIG_NXTERM_NXKBDIN
- std::fclose(stdin);
+ std::fflush(stdin);
#endif
- std::fclose(stdout);
- std::fclose(stderr);
+ std::fflush(stdout);
+ std::fflush(stderr);
#ifdef CONFIG_NXTERM_NXKBDIN
std::dup2(fd, 0);
@@ -515,12 +512,6 @@ int CNxTerm::nxterm(int argc, char *argv[])
std::dup2(fd, 1);
std::dup2(fd, 2);
-#ifdef CONFIG_NXTERM_NXKBDIN
- std::fdopen(0, "r");
-#endif
- std::fdopen(1, "w");
- std::fdopen(2, "w");
-
// And we can close our original driver file descriptor
if (fd > 2)
diff --git a/graphics/twm4nx/apps/cnxterm.cxx b/graphics/twm4nx/apps/cnxterm.cxx
index d895c81..83795ed 100644
--- a/graphics/twm4nx/apps/cnxterm.cxx
+++ b/graphics/twm4nx/apps/cnxterm.cxx
@@ -414,14 +414,11 @@ int CNxTerm::nxterm(int argc, char *argv[])
// console). (2) Don't bother trying to put debug instrumentation in the
// following because it will end up in the NxTerm window.
- std::fflush(stdout);
- std::fflush(stderr);
-
#ifdef CONFIG_NXTERM_NXKBDIN
- std::fclose(stdin);
+ std::fflush(stdin);
#endif
- std::fclose(stdout);
- std::fclose(stderr);
+ std::fflush(stdout);
+ std::fflush(stderr);
#ifdef CONFIG_NXTERM_NXKBDIN
std::dup2(fd, 0);
@@ -429,12 +426,6 @@ int CNxTerm::nxterm(int argc, char *argv[])
std::dup2(fd, 1);
std::dup2(fd, 2);
-#ifdef CONFIG_NXTERM_NXKBDIN
- std::fdopen(0, "r");
-#endif
- std::fdopen(1, "w");
- std::fdopen(2, "w");
-
// And we can close our original driver file descriptor
if (fd > 2)
diff --git a/nshlib/nsh_altconsole.c b/nshlib/nsh_altconsole.c
index 88bf540..7cf5c04 100644
--- a/nshlib/nsh_altconsole.c
+++ b/nshlib/nsh_altconsole.c
@@ -78,9 +78,9 @@ static int nsh_clone_console(FAR struct console_stdio_s *pstate)
return -ENODEV;
}
- /* Close stderr: we only close stderr if we opened the alternative one */
+ /* Flush stderr: we only flush stderr if we opened the alternative one */
- fclose(stderr);
+ flush(stderr);
/* Associate the new opened file descriptor to stderr */
@@ -101,9 +101,9 @@ static int nsh_clone_console(FAR struct console_stdio_s *pstate)
return -ENODEV;
}
- /* Close stdout: we only close stdout if we opened the alternative one */
+ /* Flush stdout: we only flush stdout if we opened the alternative one */
- fclose(stdout);
+ flush(stdout);
/* Associate the new opened file descriptor to stdout */
@@ -122,7 +122,6 @@ static int nsh_clone_console(FAR struct console_stdio_s *pstate)
pstate->cn_errstream = fdopen(pstate->cn_errfd, "a");
if (!pstate->cn_errstream)
{
- close(pstate->cn_errfd);
free(pstate);
return -EIO;
}
@@ -133,7 +132,6 @@ static int nsh_clone_console(FAR struct console_stdio_s *pstate)
pstate->cn_outstream = fdopen(pstate->cn_outfd, "a");
if (!pstate->cn_outstream)
{
- close(pstate->cn_outfd);
free(pstate);
return -EIO;
}
@@ -202,9 +200,9 @@ static int nsh_wait_inputdev(FAR struct console_stdio_s *pstate,
}
while (fd < 0);
- /* Close stdin: we only closed stdin if we opened the alternative one */
+ /* Flush stdin: we only flush stdin if we opened the alternative one */
- fclose(stdin);
+ fflush(stdin);
/* Okay.. we have successfully opened the input device. Did
* we just re-open fd 0?
@@ -225,7 +223,6 @@ static int nsh_wait_inputdev(FAR struct console_stdio_s *pstate,
pstate->cn_constream = fdopen(pstate->cn_confd, "r+");
if (!pstate->cn_constream)
{
- close(pstate->cn_confd);
free(pstate);
return -EIO;
}
diff --git a/nshlib/nsh_usbconsole.c b/nshlib/nsh_usbconsole.c
index d7069dd..be6ed48 100644
--- a/nshlib/nsh_usbconsole.c
+++ b/nshlib/nsh_usbconsole.c
@@ -77,31 +77,17 @@
static void nsh_configstdio(int fd)
{
- /* Make sure the stdin, stdout, and stderr are closed */
+ /* Make sure the stdin, stdout, and stderr are flushed */
- fclose(stdin);
- fclose(stdout);
- fclose(stderr);
+ fflush(stdin);
+ fflush(stdout);
+ fflush(stderr);
/* Dup the fd to create standard fd 0-2 */
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
-
- /* fdopen to get the stdin, stdout and stderr streams. The following logic
- * depends on the fact that the library layer will allocate FILEs in order.
- * And since we closed stdin, stdout, and stderr above, that is what we
- * should get.
- *
- * fd = 0 is stdin (read-only)
- * fd = 1 is stdout (write-only, append)
- * fd = 2 is stderr (write-only, append)
- */
-
- fdopen(0, "r");
- fdopen(1, "a");
- fdopen(2, "a");
}
/****************************************************************************