add lseek (SEEK_SET, SEEK_CUR, SEEK_END)

- still missing some filetype checking

include/metalsvm/stdio.h

@@ -23,6 +23,16 @@
  * @brief Stringstream related functions. Mainly printf-stuff.
  */
 
+#ifndef SEEK_SET
+#define	SEEK_SET	0	/* set file offset to offset */
+#endif
+#ifndef SEEK_CUR
+#define	SEEK_CUR	1	/* set file offset to current plus offset */
+#endif
+#ifndef SEEK_END
+#define	SEEK_END	2	/* set file offset to EOF plus offset */
+#endif
+
 #ifndef __STDIO_H__
 #define __STDIO_H__
 

kernel/syscall.c

@@ -29,7 +29,7 @@ static int sys_write(int fd, const char *buf, size_t len)
 {
 	unsigned int wrotebytes;
 	wrotebytes = write_fs(per_core(current_task)->fildes_table[fd].node, (uint8_t*)buf, len, per_core(current_task)->fildes_table[fd].offset);
-	kprintf("writing into filesystem -- fd:%i, Filelength:%i, Writtenbytes: %i, Bufferlength: %s \n", fd, len, wrotebytes, buf);
+	//kprintf("writing into filesystem -- fd:%i, Filelength:%i, Writtenbytes: %i, Bufferlength: %s \n", fd, len, wrotebytes, buf);
 	per_core(current_task)->fildes_table[fd].offset += wrotebytes;
 
 	return wrotebytes;
@@ -74,8 +74,31 @@ static int sys_read(int fd, const char *buf, size_t len)
  
 static int sys_lseek(int fd, off_t pos, int origin)
 {
-	kprintf("lseek used, but not ready yet");
-	return 0;
+	int ret = -EINVAL;
+
+	/* Beware: still not checking the filetype & size*/
+
+	switch(origin) 
+	{	
+	case SEEK_SET: {	/* set file offset to offset */
+			per_core(current_task)->fildes_table[fd].offset = pos;
+			ret = 0;
+			break;
+		}
+	case SEEK_CUR: {	/* set file offset to current plus offset */
+			ret = pos + per_core(current_task)->fildes_table[fd].offset;
+			break;
+		}
+	case SEEK_END: {	/* set file offset to EOF plus offset */
+			per_core(current_task)->fildes_table[fd].offset = pos + per_core(current_task)->fildes_table[fd].node->block_size;
+			ret = 0;
+			break;
+		}
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	return ret;
 }
 
 static int sys_sbrk(int incr)
@@ -150,7 +173,6 @@ int syscall_handler(uint32_t sys_nr, ...)
 			off_t pos = va_arg(vl, off_t);
  			int origin = va_arg(vl, int);
 			ret = sys_lseek(fd, pos, origin);
-			kprintf("hallo!!! %i", ret);
 			break;
 		}
 	case __NR_sbrk: {

newlib/examples/hello.c

@@ -35,6 +35,7 @@ int main(int argc, char** argv)
 	setbuf(testfile, NULL);
 	fflush(NULL);
 	fwrite("wsx", 3, 1, testfile);
+	fseek(testfile, 2, SEEK_CUR);
 	fwrite("nextnextnext", 1, 10, testfile);
 
 	fclose(testfile);

newlib/examples/test

@@ -1 +1 @@
-d
+123456789