Add build system scaffolding and libc headers

1 files changed, 39 insertions, 0 deletions

diff --git a/lib/libc/stdio/fdopen.c b/lib/libc/stdio/fdopen.c
new file mode 100644
index 00000000..f2ce0693
--- /dev/null
+++ b/lib/libc/stdio/fdopen.c
@@ -0,0 +1,39 @@
+#include <io.h>
+#include <libc.h>
+#include <unistd.h>
+#include <stdio.h>
+
+weak void __stdio_cleanup(void)
+{
+}
+
+FILE *fdopen(int fildes, const char *mode)
+{
+	FILE *fp;
+
+	if (mode == NULL ||
+	    (mode[0] != 'r' && mode[0] != 'w' && mode[0] != 'a')) {
+		return NULL;
+	}
+
+	if ((fp = calloc(1, sizeof(FILE))) == NULL)
+		return NULL;
+
+	fp->fd = fildes;
+	atomic_flag_clear(&fp->lock);
+	if (mode[0] == 'r') {
+		fp->type = _IONBF;
+	} else if (mode[0] == 'w') {
+		fp->type = _IOLBF;
+	} else if (mode[0] == 'a') {
+		fp->type = _IONBF;
+		off_t offset = lseek(fildes, 0, SEEK_END);
+		if (offset == (off_t)-1) {
+			free(fp);
+			return NULL;
+		}
+	}
+
+	__libc_fadd(fp);
+	return fp;
+}