argp facility from glibc-20030610.

[gnulib.git] / lib / linebuffer.c

diff --git a/lib/linebuffer.c b/lib/linebuffer.c
index c1a696a..770ad62 100644 (file)
--- a/lib/linebuffer.c
+++ b/lib/linebuffer.c
@@ -1,5 +1,7 @@
 /* linebuffer.c -- read arbitrarily long lines
-   Copyright (C) 1986, 1991, 1998 Free Software Foundation, Inc.
+
+   Copyright (C) 1986, 1991, 1998, 1999, 2001, 2003 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
@@ -22,10 +24,11 @@
 #endif
 
 #include <stdio.h>
+#include <sys/types.h>
 #include "linebuffer.h"
+#include "unlocked-io.h"
+#include "xalloc.h"
 
-char *xmalloc ();
-char *xrealloc ();
 void free ();
 
 /* Initialize linebuffer LINEBUFFER for use. */
@@ -35,16 +38,18 @@ initbuffer (struct linebuffer *linebuffer)
 {
   linebuffer->length = 0;
   linebuffer->size = 200;
-  linebuffer->buffer = (char *) xmalloc (linebuffer->size);
+  linebuffer->buffer = xmalloc (linebuffer->size);
 }
 
 /* Read an arbitrarily long line of text from STREAM into LINEBUFFER.
-   Remove any newline.  Does not null terminate.
-   Return zero upon error or upon end of file.
+   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.
+   Therefore the stream can contain NUL bytes, and the length
+   (including the newline) is returned in linebuffer->length.
+   Return NULL upon error, or when STREAM is empty.
    Otherwise, return LINEBUFFER.  */
-
 struct linebuffer *
-readline (struct linebuffer *linebuffer, FILE *stream)
+readlinebuffer (struct linebuffer *linebuffer, FILE *stream)
 {
   int c;
   char *buffer = linebuffer->buffer;
@@ -52,33 +57,32 @@ readline (struct linebuffer *linebuffer, FILE *stream)
   char *end = buffer + linebuffer->size; /* Sentinel. */
 
   if (feof (stream) || ferror (stream))
-    {
-      linebuffer->length = 0;
-      return 0;
-    }
+    return NULL;
 
-  while (1)
+  do
     {
       c = getc (stream);
+      if (c == EOF)
+       {
+         if (p == buffer)
+           return NULL;
+         if (p[-1] == '\n')
+           break;
+         c = '\n';
+       }
       if (p == end)
        {
          linebuffer->size *= 2;
-         buffer = (char *) xrealloc (buffer, linebuffer->size);
-         p += buffer - linebuffer->buffer;
+         buffer = xrealloc (buffer, linebuffer->size);
+         p = p - linebuffer->buffer + buffer;
          linebuffer->buffer = buffer;
          end = buffer + linebuffer->size;
        }
-      if (c == EOF || c == '\n')
-       break;
       *p++ = c;
     }
+  while (c != '\n');
 
-  if (feof (stream) && p == buffer)
-    {
-      linebuffer->length = 0;
-      return 0;
-    }
-  linebuffer->length = p - linebuffer->buffer;
+  linebuffer->length = p - buffer;
   return linebuffer;
 }