scc

commit fb8066c837ba6dc3da72fdb4d687e6b4f5ec025b
parent 346d4d01e0614d93034e8b4209a1e91e4504ea02
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Thu,  7 Dec 2017 08:31:58 +0000

[lib/c] Add fseek() and rewind()

Diffstat:
M
lib/c/src/Makefile
 | 
2
+-
A
lib/c/src/fseek.c
 | 
27
+++++++++++++++++++++++++++
A
lib/c/src/rewind.c
 | 
11
+++++++++++

3 files changed, 39 insertions(+), 1 deletion(-)
diff --git a/lib/c/src/Makefile b/lib/c/src/Makefile
@@ -8,7 +8,7 @@ OBJ = bsearch.o \
       fgets.o gets.of fgetc.o fputc.o getchar.o putchar.o \
       fputs.o puts.o fread.o fwrite.o \
       getc.o putc.o __putc.o __getc.o \
-      ferror.o feof.o clearerr.o \
+      rewind.o fseek.o ferror.o feof.o clearerr.o \
       realloc.o calloc.o malloc.o \
       assert.o strcpy.o strcmp.o strlen.o strchr.o \
       strrchr.o strcat.o strncmp.o strncpy.o strncat.o strcoll.o \
diff --git a/lib/c/src/fseek.c b/lib/c/src/fseek.c
@@ -0,0 +1,27 @@
+
+#include <stdio.h>
+#include "syscall.h"
+#undef fseek
+
+int
+fseek(FILE *fp, long off, int whence)
+{
+	if (fp->flags & _IOERR)
+		return EOF;
+
+	if ((fp->flags & _IOWRITE) && fflush(fp))
+		return -1;
+	else if (whence == SEEK_CUR && (fp->flags & _IOREAD))
+		off -= fp->wp - fp->rd;
+
+	if (_seek(fp->fd, off, type) < 0) {
+		fp->flags |= _IOERR;
+		return EOF;
+	}
+
+	if (fp->flags & _IORW)
+		fp->flags &= ~(_IOREAD | _IOWRITE);
+	fp->flags &= ~_IOEOF;
+
+	return 0;
+}
diff --git a/lib/c/src/rewind.c b/lib/c/src/rewind.c
@@ -0,0 +1,11 @@
+
+#include <stdio.h>
+#undef rewind
+
+void
+rewind(FILE *fp)
+{
+	fp->flags &= ~_IOERR;
+	fseek(fp, 0, SEEK_SET);
+	clearerr(fp);
+}