From 9e5dcfc2b43caeb2ef8da4bdde916eb645a96850 Mon Sep 17 00:00:00 2001
From: Marian Ohligs <marian.ohligs@rwth-aachen.de>
Date: Wed, 18 May 2011 18:14:23 +0200
Subject: [PATCH] add lseek (SEEK_SET, SEEK_CUR, SEEK_END) - still missing some
 filetype checking

---
 include/metalsvm/stdio.h | 10 ++++++++++
 kernel/syscall.c         | 30 ++++++++++++++++++++++++++----
 newlib/examples/hello.c  |  1 +
 newlib/examples/test     |  2 +-
 4 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/include/metalsvm/stdio.h b/include/metalsvm/stdio.h
index 6f9fc20e..527fd2b4 100644
--- a/include/metalsvm/stdio.h
+++ b/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__
 
diff --git a/kernel/syscall.c b/kernel/syscall.c
index 46471282..bff2f279 100644
--- a/kernel/syscall.c
+++ b/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: {
diff --git a/newlib/examples/hello.c b/newlib/examples/hello.c
index 6ec4d968..c0336af9 100644
--- a/newlib/examples/hello.c
+++ b/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);
diff --git a/newlib/examples/test b/newlib/examples/test
index 4bcfe98e..28d14454 100644
--- a/newlib/examples/test
+++ b/newlib/examples/test
@@ -1 +1 @@
-d
+123456789