freebsd-dev/contrib/gperf/lib/getline.cc
Dimitry Andric c807508f73 Get rid of register keyword usage in gperf, it is totally obsolete for
C++, and this allows gperf to be compiled for C++11 without a warning
about it.

MFC after:	3 days
2013-12-23 00:02:18 +00:00

120 lines
3.4 KiB
C++

/* getline.c -- Replacement for GNU C library function getline
Copyright (C) 1993, 1996, 2001-2002 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 of the
License, 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 Jan Brittenson, bson@gnu.ai.mit.edu. */
/* Specification. */
#include "getline.h"
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
/* Always add at least this many bytes when extending the buffer. */
#define MIN_CHUNK 64
/* Reads up to (and including) a TERMINATOR from STREAM into *LINEPTR + OFFSET
(and null-terminate it). *LINEPTR is a pointer returned from new [] (or
NULL), pointing to *N characters of space. It is realloc'd as
necessary. Returns the number of characters read (not including the
null terminator), or -1 on error or immediate EOF.
NOTE: There is another getstr() function declared in <curses.h>. */
static int
getstr (char **lineptr, size_t *n, FILE *stream, char terminator, size_t offset)
{
size_t nchars_avail; /* Allocated but unused chars in *LINEPTR. */
char *read_pos; /* Where we're reading into *LINEPTR. */
if (!lineptr || !n || !stream)
return -1;
if (!*lineptr)
{
*n = MIN_CHUNK;
*lineptr = new char[*n];
}
nchars_avail = *n - offset;
read_pos = *lineptr + offset;
for (;;)
{
int c = getc (stream);
/* We always want at least one char left in the buffer, since we
always (unless we get an error while reading the first char)
NUL-terminate the line buffer. */
assert (*n - nchars_avail == (size_t) (read_pos - *lineptr));
if (nchars_avail < 2)
{
if (*n > MIN_CHUNK)
*n *= 2;
else
*n += MIN_CHUNK;
nchars_avail = *n + *lineptr - read_pos;
char *new_line = new char[*n];
if (*lineptr)
{
memcpy (new_line, *lineptr, read_pos - *lineptr);
delete[] *lineptr;
}
*lineptr = new_line;
read_pos = *n - nchars_avail + *lineptr;
assert (*n - nchars_avail == (size_t) (read_pos - *lineptr));
}
if (c == EOF || ferror (stream))
{
/* Return partial line, if any. */
if (read_pos == *lineptr)
return -1;
else
break;
}
*read_pos++ = c;
nchars_avail--;
if (c == terminator)
/* Return the line. */
break;
}
/* Done - NUL terminate and return the number of chars read. */
*read_pos = '\0';
return read_pos - (*lineptr + offset);
}
int
get_line (char **lineptr, size_t *n, FILE *stream)
{
return getstr (lineptr, n, stream, '\n', 0);
}
int
get_delim (char **lineptr, size_t *n, int delimiter, FILE *stream)
{
return getstr (lineptr, n, stream, delimiter, 0);
}