1 /* linebuffer.c -- read arbitrarily long lines
3 Copyright (C) 1986, 1991, 1998-1999, 2001, 2003-2004, 2006-2007, 2009-2017
4 Free Software Foundation, Inc.
6 This program is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <https://www.gnu.org/licenses/>. */
19 /* Written by Richard Stallman. */
26 #include <sys/types.h>
27 #include "linebuffer.h"
31 # include "unlocked-io.h"
34 /* Initialize linebuffer LINEBUFFER for use. */
37 initbuffer (struct linebuffer
*linebuffer
)
39 memset (linebuffer
, 0, sizeof *linebuffer
);
43 readlinebuffer (struct linebuffer
*linebuffer
, FILE *stream
)
45 return readlinebuffer_delim (linebuffer
, stream
, '\n');
48 /* Read an arbitrarily long line of text from STREAM into LINEBUFFER.
49 Consider lines to be terminated by DELIMITER.
50 Keep the delimiter; append DELIMITER if it's the last line of a file
51 that ends in a character other than DELIMITER. Do not NUL-terminate.
52 Therefore the stream can contain NUL bytes, and the length
53 (including the delimiter) is returned in linebuffer->length.
54 Return NULL when stream is empty. Return NULL and set errno upon
55 error; callers can distinguish this case from the empty case by
56 invoking ferror (stream).
57 Otherwise, return LINEBUFFER. */
59 readlinebuffer_delim (struct linebuffer
*linebuffer
, FILE *stream
,
63 char *buffer
= linebuffer
->buffer
;
64 char *p
= linebuffer
->buffer
;
65 char *end
= buffer
+ linebuffer
->size
; /* Sentinel. */
75 if (p
== buffer
|| ferror (stream
))
77 if (p
[-1] == delimiter
)
83 size_t oldsize
= linebuffer
->size
;
84 buffer
= x2realloc (buffer
, &linebuffer
->size
);
86 linebuffer
->buffer
= buffer
;
87 end
= buffer
+ linebuffer
->size
;
91 while (c
!= delimiter
);
93 linebuffer
->length
= p
- buffer
;
97 /* Free the buffer that was allocated for linebuffer LINEBUFFER. */
100 freebuffer (struct linebuffer
*linebuffer
)
102 free (linebuffer
->buffer
);