misc: add write_file

misc/write_file.h

@@ -0,0 +1,70 @@
+/**
+ * @file write_file.h
+ * @author Ambroz Bizjak <ambrop7@gmail.com>
+ * 
+ * @section LICENSE
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the author nor the
+ *    names of its contributors may be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef BADVPN_WRITE_FILE_H
+#define BADVPN_WRITE_FILE_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#include <misc/debug.h>
+
+static int write_file (const char *file, const uint8_t *data, size_t len)
+{
+    FILE *f = fopen(file, "w");
+    if (!f) {
+        goto fail0;
+    }
+    
+    while (len > 0) {
+        size_t res = fwrite(data, 1, len, f);
+        if (res == 0) {
+            goto fail1;
+        }
+        
+        ASSERT(res <= len)
+        
+        data += res;
+        len -= res;
+    }
+    
+    if (fclose(f) != 0) {
+        return 0;
+    }
+    
+    return 1;
+    
+fail1:
+    fclose(f);
+fail0:
+    return 0;
+}
+
+#endif