/* 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
#endif
#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
#include "linebuffer.h"
-
-char *xmalloc ();
-char *xrealloc ();
-void free ();
+#include "unlocked-io.h"
+#include "xalloc.h"
/* Initialize linebuffer LINEBUFFER for use. */
void
initbuffer (struct linebuffer *linebuffer)
{
- linebuffer->length = 0;
- linebuffer->size = 200;
- linebuffer->buffer = (char *) xmalloc (linebuffer->size);
+ memset (linebuffer, 0, sizeof *linebuffer);
}
/* 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 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 *
-readline (struct linebuffer *linebuffer, FILE *stream)
+readlinebuffer (struct linebuffer *linebuffer, FILE *stream)
{
int c;
char *buffer = linebuffer->buffer;
char *p = linebuffer->buffer;
char *end = buffer + linebuffer->size; /* Sentinel. */
- if (feof (stream) || ferror (stream))
- {
- linebuffer->length = 0;
- return 0;
- }
+ if (feof (stream))
+ return NULL;
- while (1)
+ do
{
c = getc (stream);
+ if (c == EOF)
+ {
+ if (p == buffer || ferror (stream))
+ 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;
+ size_t oldsize = linebuffer->size;
+ buffer = x2realloc (buffer, &linebuffer->size);
+ p = buffer + oldsize;
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;
}
-/* Free linebuffer LINEBUFFER and its data, all allocated with malloc. */
+/* Free the buffer that was allocated for linebuffer LINEBUFFER. */
void
freebuffer (struct linebuffer *linebuffer)
{
free (linebuffer->buffer);
- free (linebuffer);
}