1 files changed, 89 insertions, 6 deletions

diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index 4c6af3016e2e..149c5ca59aad 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -18,40 +18,123 @@
 #define EOF (-1)
 #endif
 
+/* just define FILE as a non-empty type */
+typedef struct FILE {
+	char dummy[1];
+} FILE;
+
+/* We define the 3 common stdio files as constant invalid pointers that
+ * are easily recognized.
+ */
+static __attribute__((unused)) FILE* const stdin  = (FILE*)-3;
+static __attribute__((unused)) FILE* const stdout = (FILE*)-2;
+static __attribute__((unused)) FILE* const stderr = (FILE*)-1;
+
+/* getc(), fgetc(), getchar() */
+
+#define getc(stream) fgetc(stream)
+
 static __attribute__((unused))
-int getchar(void)
+int fgetc(FILE* stream)
 {
 	unsigned char ch;
+	int fd;
 
-	if (read(0, &ch, 1) <= 0)
+	if (stream < stdin || stream > stderr)
+		return EOF;
+
+	fd = 3 + (long)stream;
+
+	if (read(fd, &ch, 1) <= 0)
 		return EOF;
 	return ch;
 }
 
 static __attribute__((unused))
-int putchar(int c)
+int getchar(void)
+{
+	return fgetc(stdin);
+}
+
+
+/* putc(), fputc(), putchar() */
+
+#define putc(c, stream) fputc(c, stream)
+
+static __attribute__((unused))
+int fputc(int c, FILE* stream)
 {
 	unsigned char ch = c;
+	int fd;
 
-	if (write(1, &ch, 1) <= 0)
+	if (stream < stdin || stream > stderr)
+		return EOF;
+
+	fd = 3 + (long)stream;
+
+	if (write(fd, &ch, 1) <= 0)
 		return EOF;
 	return ch;
 }
 
 static __attribute__((unused))
-int puts(const char *s)
+int putchar(int c)
+{
+	return fputc(c, stdout);
+}
+
+
+/* puts(), fputs(). Note that puts() emits '\n' but not fputs(). */
+
+static __attribute__((unused))
+int fputs(const char *s, FILE *stream)
 {
 	size_t len = strlen(s);
 	ssize_t ret;
+	int fd;
+
+	if (stream < stdin || stream > stderr)
+		return EOF;
+
+	fd = 3 + (long)stream;
 
 	while (len > 0) {
-		ret = write(1, s, len);
+		ret = write(fd, s, len);
 		if (ret <= 0)
 			return EOF;
 		s += ret;
 		len -= ret;
 	}
+	return 0;
+}
+
+static __attribute__((unused))
+int puts(const char *s)
+{
+	if (fputs(s, stdout) == EOF)
+		return EOF;
 	return putchar('\n');
 }
 
+
+/* fgets() */
+static __attribute__((unused))
+char *fgets(char *s, int size, FILE *stream)
+{
+	int ofs;
+	int c;
+
+	for (ofs = 0; ofs + 1 < size;) {
+		c = fgetc(stream);
+		if (c == EOF)
+			break;
+		s[ofs++] = c;
+		if (c == '\n')
+			break;
+	}
+	if (ofs < size)
+		s[ofs] = 0;
+	return ofs ? s : NULL;
+}
+
 #endif /* _NOLIBC_STDIO_H */