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Posted to commits@nuttx.apache.org by ag...@apache.org on 2020/06/23 16:35:15 UTC
[incubator-nuttx] 02/02: libc: Implement pathconf and fpathconf
This is an automated email from the ASF dual-hosted git repository.
aguettouche pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git
commit d24bd782a9a773480e9ecd4fe0340b5a143996fb
Author: Xiang Xiao <xi...@xiaomi.com>
AuthorDate: Mon Jun 22 14:34:59 2020 +0800
libc: Implement pathconf and fpathconf
specified here:
https://pubs.opengroup.org/onlinepubs/009695399/functions/fpathconf.html
note: only _PC_PATH_MAX is handled now
Signed-off-by: Xiang Xiao <xi...@xiaomi.com>
Change-Id: Idd323dc10e8f31f10dd1fc64f467227808c11dbd
---
include/unistd.h | 28 ++++++++-
libs/libc/unistd/Make.defs | 2 +-
libs/libc/unistd/lib_pathconf.c | 132 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 160 insertions(+), 2 deletions(-)
diff --git a/include/unistd.h b/include/unistd.h
index e51ab9f..1e3351e 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -103,7 +103,31 @@
#undef _POSIX_ASYNC_IO
#undef _POSIX_PRIO_IO
-/* Constants used with POSIX sysconf(). sysconf() will return -2 and set
+/* Constants used with POSIX pathconf(). pathconf() will return -1 and set
+ * errno to ENOSYS for most of these.
+ */
+
+#define _PC_2_SYMLINKS 0x0001
+#define _PC_ALLOC_SIZE_MIN 0x0002
+#define _PC_ASYNC_IO 0x0003
+#define _PC_CHOWN_RESTRICTED 0x0004
+#define _PC_FILESIZEBITS 0x0005
+#define _PC_LINK_MAX 0x0006
+#define _PC_MAX_CANON 0x0007
+#define _PC_MAX_INPUT 0x0008
+#define _PC_NAME_MAX 0x0009
+#define _PC_NO_TRUNC 0x000a
+#define _PC_PATH_MAX 0x000b
+#define _PC_PIPE_BUF 0x000c
+#define _PC_PRIO_IO 0x000d
+#define _PC_REC_INCR_XFER_SIZE 0x000e
+#define _PC_REC_MIN_XFER_SIZE 0x000f
+#define _PC_REC_XFER_ALIGN 0x0010
+#define _PC_SYMLINK_MAX 0x0011
+#define _PC_SYNC_IO 0x0012
+#define _PC_VDISABLE 0x0013
+
+/* Constants used with POSIX sysconf(). sysconf() will return -1 and set
* errno to ENOSYS for most of these.
*/
@@ -365,6 +389,8 @@ int sethostname(FAR const char *name, size_t size);
/* Get configurable system variables */
long sysconf(int name);
+long fpathconf(int fildes, int name);
+long pathconf(FAR const char *path, int name);
/* User and group identity management */
diff --git a/libs/libc/unistd/Make.defs b/libs/libc/unistd/Make.defs
index b3b2a82..760c3b7 100644
--- a/libs/libc/unistd/Make.defs
+++ b/libs/libc/unistd/Make.defs
@@ -35,7 +35,7 @@
# Add the unistd C files to the build
-CSRCS += lib_access.c lib_daemon.c lib_swab.c lib_sysconf.c
+CSRCS += lib_access.c lib_daemon.c lib_swab.c lib_pathconf.c lib_sysconf.c
CSRCS += lib_getopt.c lib_getoptargp.c lib_getoptindp.c lib_getoptoptp.c
CSRCS += lib_alarm.c lib_sleep.c lib_usleep.c
CSRCS += lib_seteuid.c lib_setegid.c lib_geteuid.c lib_getegid.c
diff --git a/libs/libc/unistd/lib_pathconf.c b/libs/libc/unistd/lib_pathconf.c
new file mode 100644
index 0000000..5b05a4f
--- /dev/null
+++ b/libs/libc/unistd/lib_pathconf.c
@@ -0,0 +1,132 @@
+/****************************************************************************
+ * libs/libc/unistd/lib_pathconf.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <unistd.h>
+#include <limits.h>
+#include <errno.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: fpathconf/pathconf
+ *
+ * Description:
+ * The fpathconf() and pathconf() functions shall determine the current
+ * value of a configurable limit or option (variable) that is associated
+ * with a file or directory.
+ *
+ * For pathconf(), the path argument points to the pathname of a file or
+ * directory.
+ *
+ * For fpathconf(), the fildes argument is an open file descriptor.
+ *
+ * The name argument represents the variable to be queried relative to that
+ * file or directory. Implementations shall support all of the variables
+ * listed in the following table and may support others. The variables in
+ * the following table come from <limits.h> or <unistd.h> and the symbolic
+ * constants, defined in <unistd.h>, are the corresponding values used for
+ * name.
+ *
+ * Variable Value of Name
+ *
+ * {FILESIZEBITS} _PC_FILESIZEBITS
+ * {LINK_MAX} _PC_LINK_MAX
+ * {MAX_CANON} _PC_MAX_CANON
+ * {MAX_INPUT} _PC_MAX_INPUT
+ * {NAME_MAX} _PC_NAME_MAX
+ * {PATH_MAX} _PC_PATH_MAX
+ * {PIPE_BUF} _PC_PIPE_BUF
+ * {POSIX2_SYMLINKS} _PC_2_SYMLINKS
+ * {POSIX_ALLOC_SIZE_MIN} _PC_ALLOC_SIZE_MIN
+ * {POSIX_REC_INCR_XFER_SIZE} _PC_REC_INCR_XFER_SIZE
+ * {POSIX_REC_MAX_XFER_SIZE} _PC_REC_MAX_XFER_SIZE
+ * {POSIX_REC_MIN_XFER_SIZE} _PC_REC_MIN_XFER_SIZE
+ * {POSIX_REC_XFER_ALIGN} _PC_REC_XFER_ALIGN
+ * {SYMLINK_MAX} _PC_SYMLINK_MAX
+ * _POSIX_CHOWN_RESTRICTED _PC_CHOWN_RESTRICTED
+ * _POSIX_NO_TRUNC _PC_NO_TRUNC
+ * _POSIX_VDISABLE _PC_VDISABLE
+ * _POSIX_ASYNC_IO _PC_ASYNC_IO
+ * _POSIX_PRIO_IO _PC_PRIO_IO
+ * _POSIX_SYNC_IO _PC_SYNC_IO
+ *
+ * Returned Value:
+ * If name is an invalid value, both pathconf() and fpathconf() shall
+ * return -1 and set errno to indicate the error.
+ *
+ * If the variable corresponding to name has no limit for the path or file
+ * descriptor, both pathconf() and fpathconf() shall return -1 without
+ * changing errno. If the implementation needs to use path to determine the
+ * value of name and the implementation does not support the association of
+ * name with the file specified by path, or if the process did not have
+ * appropriate privileges to query the file specified by path, or path does
+ * not exist, pathconf() shall return -1 and set errno to indicate the
+ * error.
+ *
+ * If the implementation needs to use fildes to determine the value of name
+ * and the implementation does not support the association of name with the
+ * file specified by fildes, or if fildes is an invalid file descriptor,
+ * fpathconf() shall return -1 and set errno to indicate the error.
+ *
+ * Otherwise, pathconf() or fpathconf() shall return the current variable
+ * value for the file or directory without changing errno. The value
+ * returned shall not be more restrictive than the corresponding value
+ * available to the application when it was compiled with the
+ * implementation's <limits.h> or <unistd.h>.
+ *
+ * If the variable corresponding to name is dependent on an unsupported
+ * option, the results are unspecified.
+ *
+ ****************************************************************************/
+
+long fpathconf(int fildes, int name)
+{
+ /* NOTE: The initialize implementation of this interface is very sparse.
+ * It was originally created to support only the functionality of libcxx
+ * but can be extended to support as much of the standard POSIX as is
+ * necessary.
+ */
+
+ switch (name)
+ {
+ case _PC_PATH_MAX:
+ return PATH_MAX;
+
+ default:
+
+ /* Assume valid but not implemented for the time being */
+
+ set_errno(ENOSYS);
+ return ERROR;
+ }
+}
+
+long pathconf(FAR const char *path, int name)
+{
+ return fpathconf(-1, name);
+}