1 files changed, 42 insertions, 0 deletions
diff --git a/stdio/setvbuf.c b/stdio/setvbuf.c
new file mode 100644
index 0000000..4149bdd
--- /dev/null
+++ b/stdio/setvbuf.c
@@ -0,0 +1,42 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/stdio/stdio.h"
+#include "libc/sysv/errfuns.h"
+
+/**
+ * Tunes buffering settings for an stdio stream.
+ *
+ * @param mode may be _IOFBF, _IOLBF, or _IONBF
+ * @param buf may optionally be non-NULL to set the stream's underlying
+ *     buffer, which the stream will own, but won't free, otherwise the
+ *     existing buffer is used
+ * @param size is ignored if buf is NULL
+ * @return 0 on success or -1 on error
+ */
+int setvbuf(FILE *f, char *buf, int mode, size_t size) {
+  if (buf) {
+    if (!size) size = BUFSIZ;
+    if (!f->nofree && f->buf != buf) free_s(&f->buf);
+    f->buf = buf;
+    f->size = size;
+    f->nofree = true;
+  }
+  f->bufmode = mode;
+  return 0;
+}