fd: Improve documentation of write_all().

[paraslash.git] / fd.c

diff --git a/fd.c b/fd.c
index 763f756cdc3b5086ee9d26f432dbbfb760e02e4a..180032daa6d0f7bf11a63984480842b007c316c6 100644 (file)
--- a/fd.c
+++ b/fd.c
@@ -126,14 +126,15 @@ int xwrite(int fd, const char *buf, size_t len)
 }
 
 /**
- * Write all data to a file descriptor.
+ * Write to a file descriptor, fail on short writes.
  *
  * \param fd The file descriptor.
- * \param buf The buffer to be sent.
- * \param len The length of \a buf.
+ * \param buf The buffer to be written.
+ * \param len The length of the buffer.
  *
- * This is like \ref xwrite() but returns \p -E_SHORT_WRITE if not
- * all data could be written.
+ * For blocking file descriptors this function behaves identical to \ref
+ * xwrite(). For non-blocking file descriptors it returns -E_SHORT_WRITE
+ * (rather than a value less than len) if not all data could be written.
  *
  * \return Number of bytes written on success, negative error code else.
  */
@@ -149,12 +150,20 @@ int write_all(int fd, const char *buf, size_t len)
 }
 
 /**
- * Write a buffer given by a format string.
+ * A fprintf-like function for raw file descriptors.
+ *
+ * This function creates a string buffer according to the given format and
+ * writes this buffer to a file descriptor.
  *
  * \param fd The file descriptor.
  * \param fmt A format string.
  *
+ * The difference to fprintf(3) is that the first argument is a file
+ * descriptor, not a FILE pointer. This function does not rely on stdio.
+ *
  * \return The return value of the underlying call to \ref write_all().
+ *
+ * \sa fprintf(3), \ref xvasprintf().
  */
 __printf_2_3 int write_va_buffer(int fd, const char *fmt, ...)
 {