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-rw-r--r--lib/linebuffer.c96
1 files changed, 96 insertions, 0 deletions
diff --git a/lib/linebuffer.c b/lib/linebuffer.c
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+/* linebuffer.c -- read arbitrarily long lines
+
+ Copyright (C) 1986, 1991, 1998, 1999, 2001, 2003, 2004, 2006 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
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+/* Written by Richard Stallman. */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include "linebuffer.h"
+#include "xalloc.h"
+
+#if USE_UNLOCKED_IO
+# include "unlocked-io.h"
+#endif
+
+/* Initialize linebuffer LINEBUFFER for use. */
+
+void
+initbuffer (struct linebuffer *linebuffer)
+{
+ memset (linebuffer, 0, sizeof *linebuffer);
+}
+
+/* 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.
+ 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 *
+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))
+ return NULL;
+
+ do
+ {
+ c = getc (stream);
+ if (c == EOF)
+ {
+ if (p == buffer || ferror (stream))
+ return NULL;
+ if (p[-1] == '\n')
+ break;
+ c = '\n';
+ }
+ if (p == end)
+ {
+ size_t oldsize = linebuffer->size;
+ buffer = x2realloc (buffer, &linebuffer->size);
+ p = buffer + oldsize;
+ linebuffer->buffer = buffer;
+ end = buffer + linebuffer->size;
+ }
+ *p++ = c;
+ }
+ while (c != '\n');
+
+ linebuffer->length = p - buffer;
+ return linebuffer;
+}
+
+/* Free the buffer that was allocated for linebuffer LINEBUFFER. */
+
+void
+freebuffer (struct linebuffer *linebuffer)
+{
+ free (linebuffer->buffer);
+}