Add GetStat

Wraps stat() with mapped errno.

src/libpsl-native/src/CMakeLists.txt

@@ -1,4 +1,5 @@
 add_library(psl-native SHARED
+  getstat.cpp
   getcurrentprocessorid.cpp
   getusername.cpp
   getcomputername.cpp

src/libpsl-native/src/getstat.cpp

@@ -0,0 +1,96 @@
+//! @file getstat.cpp
+//! @author Andrew Schwartzmeyer <andschwa@microsoft.com>
+//! @brief returns the stat of a file
+
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <pwd.h>
+#include <string.h>
+#include <unistd.h>
+#include "getstat.h"
+
+//! @brief GetStat returns the stat of a file. This simply delegates to the
+//! stat() system call and maps errno to the expected values for GetLastError.
+//!
+//! GetStat
+//!
+//! @param[in] path
+//! @parblock
+//! A pointer to the buffer that contains the file name
+//!
+//! char* is marshaled as an LPStr, which on Linux is UTF-8.
+//! @endparblock
+//!
+//! @param[in] stat
+//! @parblock
+//! A pointer to the buffer in which to place the stat information
+//! @endparblock
+//!
+//! @exception errno Passes these errors via errno to GetLastError:
+//! - ERROR_INVALID_PARAMETER: parameter is not valid
+//! - ERROR_FILE_NOT_FOUND: file does not exist
+//! - ERROR_ACCESS_DENIED: access is denied
+//! - ERROR_INVALID_ADDRESS: attempt to access invalid address
+//! - ERROR_STOPPED_ON_SYMLINK: too many symbolic links
+//! - ERROR_GEN_FAILURE: I/O error occurred
+//! - ERROR_INVALID_NAME: file provided is not a symbolic link
+//! - ERROR_INVALID_FUNCTION: incorrect function
+//! - ERROR_BAD_PATH_NAME: pathname is too long
+//! - ERROR_OUTOFMEMORY insufficient kernel memory
+//!
+//! @retval 0 if successful
+//! @retval -1 if failed
+//!
+
+int32_t GetStat(const char* path, struct stat* buf)
+{
+    errno = 0;
+
+    if (!path)
+    {
+        errno = ERROR_INVALID_PARAMETER;
+        return -1;
+    }
+
+    int32_t ret = stat(path, buf);
+
+    if (ret != 0)
+    {
+        switch(errno)
+        {
+        case EACCES:
+            errno = ERROR_ACCESS_DENIED;
+            break;
+        case EBADF:
+            errno = ERROR_FILE_NOT_FOUND;
+            break;
+        case EFAULT:
+            errno = ERROR_INVALID_ADDRESS;
+            break;
+        case ELOOP:
+            errno = ERROR_STOPPED_ON_SYMLINK;
+            break;
+        case ENAMETOOLONG:
+            errno = ERROR_GEN_FAILURE;
+            break;
+        case ENOENT:
+            errno = ERROR_FILE_NOT_FOUND;
+            break;
+        case ENOMEM:
+            errno = ERROR_NO_SUCH_USER;
+            break;
+        case ENOTDIR:
+            errno = ERROR_INVALID_NAME;
+            break;
+        case EOVERFLOW:
+            errno = ERROR_BUFFER_OVERFLOW;
+            break;
+        default:
+            errno = ERROR_INVALID_FUNCTION;
+        }
+        return -1;
+    }
+
+    return 0;
+}

src/libpsl-native/src/getstat.h

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <sys/stat.h>
+#include "pal.h"
+
+PAL_BEGIN_EXTERNC
+
+int32_t GetStat(const char* path, struct stat* buf);
+
+PAL_END_EXTERNC