vcs-svn/line_buffer.txt

   1 line_buffer API
   2 ===============
   3
   4 The line_buffer library provides a convenient interface for
   5 mostly-line-oriented input.
   6
   7 Each line is not permitted to exceed 10000 bytes.  The provided
   8 functions are not thread-safe or async-signal-safe, and like
   9 `fgets()`, they generally do not function correctly if interrupted
  10 by a signal without SA_RESTART set.
  11
  12 Calling sequence
  13 ----------------
  14
  15 The calling program:
  16
  17  - specifies a file to read with `buffer_init`
  18  - processes input with `buffer_read_line`, `buffer_read_string`,
  19    `buffer_skip_bytes`, and `buffer_copy_bytes`
  20  - closes the file with `buffer_deinit`, perhaps to start over and
  21    read another file.
  22
  23 Before exiting, the caller can use `buffer_reset` to deallocate
  24 resources for the benefit of profiling tools.
  25
  26 Functions
  27 ---------
  28
  29 `buffer_init`::
  30         Open the named file for input.  If filename is NULL,
  31         start reading from stdin.  On failure, returns -1 (with
  32         errno indicating the nature of the failure).
  33
  34 `buffer_deinit`::
  35         Stop reading from the current file (closing it unless
  36         it was stdin).  Returns nonzero if `fclose` fails or
  37         the error indicator was set.
  38
  39 `buffer_read_line`::
  40         Read a line and strip off the trailing newline.
  41         On failure or end of file, returns NULL.
  42
  43 `buffer_read_string`::
  44         Read `len` characters of input or up to the end of the
  45         file, whichever comes first.  Returns NULL on error.
  46         Returns whatever characters were read (possibly "")
  47         for end of file.
  48
  49 `buffer_copy_bytes`::
  50         Read `len` bytes of input and dump them to the standard output
  51         stream.  Returns early for error or end of file.
  52
  53 `buffer_skip_bytes`::
  54         Discards `len` bytes from the input stream (stopping early
  55         if necessary because of an error or eof).
  56
  57 `buffer_reset`::
  58         Deallocates non-static buffers.