From: Eric Biggers <ebiggers3@gmail.com>
Date: Thu, 26 Jun 2014 01:03:50 +0000 (-0500)
Subject: Windows replacement for fopen(path, "a")
X-Git-Tag: v1.7.1~76
X-Git-Url: https://wimlib.net/git/?p=wimlib;a=commitdiff_plain;h=7d7e51b225eb2a74d26c089929aadffb1f0549c6

Windows replacement for fopen(path, "a")
---

diff --git a/include/wimlib/win32.h b/include/wimlib/win32.h
index 9d47ec6c..c8be8c80 100644
--- a/include/wimlib/win32.h
+++ b/include/wimlib/win32.h
@@ -47,6 +47,9 @@ win32_truncate_replacement(const tchar *path, off_t size);
 extern int
 win32_strerror_r_replacement(int errnum, tchar *buf, size_t buflen);
 
+extern FILE *
+win32_open_logfile(const wchar_t *path);
+
 extern ssize_t
 pread(int fd, void *buf, size_t count, off_t offset);
 
diff --git a/src/util.c b/src/util.c
index 3b45ce6f..60bab76a 100644
--- a/src/util.c
+++ b/src/util.c
@@ -210,7 +210,11 @@ wimlib_set_error_file_by_name(const tchar *path)
 #ifdef ENABLE_ERROR_MESSAGES
 	FILE *fp;
 
-	fp = tfopen(path, "a");
+#ifdef __WIN32__
+	fp = win32_open_logfile(path);
+#else
+	fp = fopen(path, "a");
+#endif
 	if (!fp)
 		return WIMLIB_ERR_OPEN;
 	wimlib_set_error_file(fp);
diff --git a/src/win32_replacements.c b/src/win32_replacements.c
index 5b3017a3..30822550 100644
--- a/src/win32_replacements.c
+++ b/src/win32_replacements.c
@@ -31,6 +31,7 @@
 #include <errno.h>
 #include <pthread.h>
 #include <io.h>	/* for _get_osfhandle()  */
+#include <fcntl.h>
 
 #include "wimlib/win32_common.h"
 
@@ -372,4 +373,33 @@ globfree(glob_t *pglob)
 	FREE(pglob->gl_pathv);
 }
 
+/* Replacement for fopen(path, "a") that doesn't prevent other processes from
+ * reading the file  */
+FILE *
+win32_open_logfile(const wchar_t *path)
+{
+	HANDLE h;
+	int fd;
+	FILE *fp;
+
+	h = CreateFile(path, FILE_APPEND_DATA, FILE_SHARE_VALID_FLAGS,
+		       NULL, OPEN_ALWAYS, 0, NULL);
+	if (h == INVALID_HANDLE_VALUE)
+		return NULL;
+
+	fd = _open_osfhandle((intptr_t)h, O_APPEND);
+	if (fd < 0) {
+		CloseHandle(h);
+		return NULL;
+	}
+
+	fp = fdopen(fd, "a");
+	if (!fp) {
+		close(fd);
+		return NULL;
+	}
+
+	return fp;
+}
+
 #endif /* __WIN32__ */