Implement readlinebuffer_delim, generalizing readlinebuffer

[James Youngman]

I have just implemented "uniq -z" (analogous with sort -z) but needed
to generalize readlinebuffer() to do so.


2007-05-12  James Youngman  <address@hidden>

       * lib/linebuffer.c (readlinebuffer_delim): Like
        readlinebuffer, but use the delimiter the caller
        specifies.
        (readlinebuffer): Just call readlinebuffer_delim with '\n'
        as the delimiter.
       * lib/linebuffer.h (readlinebuffer_delim): Declare it.
        
Index: lib/linebuffer.c
===================================================================
RCS file: /sources/gnulib/gnulib/lib/linebuffer.c,v
retrieving revision 1.21
diff -u -r1.21 linebuffer.c
--- lib/linebuffer.c    13 Sep 2006 22:38:14 -0000      1.21
+++ lib/linebuffer.c    12 May 2007 10:35:19 -0000
@@ -1,7 +1,7 @@
/* linebuffer.c -- read arbitrarily long lines

-   Copyright (C) 1986, 1991, 1998, 1999, 2001, 2003, 2004, 2006 Free
-   Software Foundation, Inc.
+   Copyright (C) 1986, 1991, 1998, 1999, 2001, 2003, 2004, 2006, 2007
+   Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -40,17 +40,25 @@
  memset (linebuffer, 0, sizeof *linebuffer);
}

+struct linebuffer *
+readlinebuffer (struct linebuffer *linebuffer, FILE *stream)
+{
+  return readlinebuffer_delim(linebuffer, stream, '\n');
+}
+
+
/* Read an arbitrarily long line of text from STREAM into LINEBUFFER.
-   Keep the newline; append a newline if it's the last line of a file
-   that ends in a non-newline character.  Do not null terminate.
+   Consder lines to be terminated by DELIMITER.
+   Keep the delimiter; append DELIMITER if it's the last line of a file
+   that ends in a character other than DELIMITER.  Do not null terminate.
   Therefore the stream can contain NUL bytes, and the length
-   (including the newline) is returned in linebuffer->length.
+   (including the delimiter) is returned in linebuffer->length.
   Return NULL when stream is empty.  Return NULL and set errno upon
   error; callers can distinguish this case from the empty case by
   invoking ferror (stream).
   Otherwise, return LINEBUFFER.  */
struct linebuffer *
-readlinebuffer (struct linebuffer *linebuffer, FILE *stream)
+readlinebuffer_delim (struct linebuffer *linebuffer, FILE *stream,
char delimiter)
{
  int c;
  char *buffer = linebuffer->buffer;
@@ -67,9 +75,9 @@
        {
          if (p == buffer || ferror (stream))
            return NULL;
-         if (p[-1] == '\n')
+         if (p[-1] == delimiter)
            break;
-         c = '\n';
+         c = delimiter;
        }
      if (p == end)
        {
@@ -81,7 +89,7 @@
        }
      *p++ = c;
    }
-  while (c != '\n');
+  while (c != delimiter);

  linebuffer->length = p - buffer;
  return linebuffer;
Index: lib/linebuffer.h
===================================================================
RCS file: /sources/gnulib/gnulib/lib/linebuffer.h,v
retrieving revision 1.15
diff -u -r1.15 linebuffer.h
--- lib/linebuffer.h    14 May 2005 06:03:58 -0000      1.15
+++ lib/linebuffer.h    12 May 2007 10:35:19 -0000
@@ -35,6 +35,13 @@
void initbuffer (struct linebuffer *linebuffer);

/* Read an arbitrarily long line of text from STREAM into LINEBUFFER.
+   Consider lines to be terminated by DELIMITER.
+   Keep the delimiter; append DELIMITER if we reach EOF and it wasn't the last
+   character in the file.  Do not null terminate.
+   Return LINEBUFFER, except at end of file return 0.  */
+struct linebuffer *readlinebuffer_delim (struct linebuffer
*linebuffer, FILE *stream, char delimiter);
+
+/* Read an arbitrarily long line of text from STREAM into LINEBUFFER.
   Keep the newline; append a newline if it's the last line of a file
   that ends in a non-newline character.  Do not null terminate.
   Return LINEBUFFER, except at end of file return 0.  */