1 files changed, 120 insertions, 0 deletions
diff --git a/src/user/lib/stdlib.c b/src/user/lib/stdlib.c
new file mode 100644
index 0000000..c055d04
--- /dev/null
+++ b/src/user/lib/stdlib.c
@@ -0,0 +1,120 @@
+#include <user/lib/stdlib.h>
+#include <shared/printf.h>
+#include <shared/syscalls.h>
+
+// TODO oh god this garbage - malloc, actually open, [...]
+static libc_file _stdin_null  = { .fd = 0 };
+static libc_file _stdout_null = { .fd = 1 };
+
+libc_file *stdin = &_stdin_null, *stdout = &_stdout_null;
+
+static void backend_file(void *arg, const char *buf, size_t len) {
+	file_write((libc_file*)arg, buf, len);
+}
+
+int printf(const char *fmt, ...) {
+	int ret = 0;
+	va_list argp;
+	va_start(argp, fmt);
+	ret = __printf_internal(fmt, argp, backend_file, (void*)stdout);
+	va_end(argp);
+	return ret;
+}
+
+static void backend_buf(void *arg, const char *buf, size_t len) {
+	char **ptrs = arg;
+	size_t space = ptrs[1] - ptrs[0];
+	if (len > space) len = space;
+	memcpy(ptrs[0], buf, len);
+	ptrs[0] += len;
+}
+
+int snprintf(char *str, size_t len, const char *fmt, ...) {
+	int ret = 0;
+	char *ptrs[2] = {str, str + len};
+	va_list argp;
+	va_start(argp, fmt);
+	ret = __printf_internal(fmt, argp, backend_buf, &ptrs);
+	va_end(argp);
+	if (ptrs[0] < ptrs[1]) *ptrs[0] = '\0';
+	return ret;
+}
+
+int _klogf(const char *fmt, ...) {
+	// idiotic. however, this hack won't matter anyways
+	char buf[256];
+	int ret = 0;
+	char *ptrs[2] = {buf, buf + sizeof buf};
+	va_list argp;
+	va_start(argp, fmt);
+	ret = __printf_internal(fmt, argp, backend_buf, &ptrs);
+	va_end(argp);
+	if (ptrs[0] < ptrs[1]) *ptrs[0] = '\0';
+	_syscall_debug_klog(buf, ret);
+	return ret;
+}
+
+
+libc_file *file_open(const char *path, int flags) {
+	handle_t h = _syscall_open(path, strlen(path), flags);
+	libc_file *f;
+	if (h < 0) return NULL;
+
+	f = malloc(sizeof *f);
+	if (!f) {
+		_syscall_close(h);
+		return NULL;
+	}
+	f->pos = 0;
+	f->eof = false;
+	f->fd = h;
+	return f;
+}
+
+libc_file *file_reopen(libc_file *f, const char *path, int flags) {
+	/* partially based on the musl implementation of freopen */
+	libc_file *f2;
+	if (!path) goto fail;
+	f2 = file_open(path, flags);
+	if (!f2) goto fail;
+
+	/* shouldn't happen, but if it happens, let's roll with it. */
+	if (f->fd == f2->fd) f2->fd = -1;
+
+	if (_syscall_dup(f2->fd, f->fd, 0) < 0) goto fail2;
+	f->pos = f2->pos;
+	f->eof = f2->eof;
+	file_close(f2);
+	return f;
+
+fail2:
+	file_close(f2);
+fail:
+	file_close(f);
+	return NULL;
+}
+
+int file_read(libc_file *f, char *buf, size_t len) {
+	if (f->fd < 0) return -1;
+
+	int res = _syscall_read(f->fd, buf, len, f->pos);
+	if (res < 0) return res;
+	if (res == 0 && len > 0) f->eof = true;
+	f->pos += res;
+	return res;
+}
+
+int file_write(libc_file *f, const char *buf, size_t len) {
+	if (f->fd < 0) return -1;
+
+	int res = _syscall_write(f->fd, buf, len, f->pos);
+	if (res < 0) return res;
+	f->pos += res;
+	return res;
+}
+
+void file_close(libc_file *f) {
+	if (f->fd > 0) _syscall_close(f->fd);
+	if (f != &_stdin_null && f != &_stdout_null)
+		free(f);
+}