freebsd-dev/contrib/cvs/lib/getline.c
peter 732631db68 Import cvs-1.9.23 as at 19980123. There are a number of really nice
things fixed in here, including the '-ko' vs. -A problem with
remote cvs which caused all files with -ko to be resent each time
(which is damn painful over a modem, I can tell you).  It also found a
heap of stray empty directories that should have been pruned with the -P
flag to cvs update but were not for some reason.

It also has the fully integrated rcs and diff, so no more fork/exec
overheads for rcs,ci,patch,diff,etc.  This means that it parses the control
data in the rcs files only once rather than twice or more.

If the 'cvs diff' vs. Index thing is going to be fixed for future patch
compatability, this is the place to do it.
1998-01-26 03:09:57 +00:00

146 lines
3.3 KiB
C

/* getline.c -- Replacement for GNU C library function getline
Copyright (C) 1993 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. */
/* Written by Jan Brittenson, bson@gnu.ai.mit.edu. */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <sys/types.h>
#include <stdio.h>
#include <assert.h>
#include <errno.h>
#if STDC_HEADERS
#include <stdlib.h>
#else
char *malloc (), *realloc ();
#endif
/* Always add at least this many bytes when extending the buffer. */
#define MIN_CHUNK 64
/* Read up to (and including) a TERMINATOR from STREAM into *LINEPTR
+ OFFSET (and null-terminate it). *LINEPTR is a pointer returned from
malloc (or NULL), pointing to *N characters of space. It is realloc'd
as necessary. Return the number of characters read (not including the
null terminator), or -1 on error or EOF. On a -1 return, the caller
should check feof(), if not then errno has been set to indicate
the error. */
int
getstr (lineptr, n, stream, terminator, offset)
char **lineptr;
size_t *n;
FILE *stream;
char terminator;
int offset;
{
int nchars_avail; /* Allocated but unused chars in *LINEPTR. */
char *read_pos; /* Where we're reading into *LINEPTR. */
int ret;
if (!lineptr || !n || !stream)
{
errno = EINVAL;
return -1;
}
if (!*lineptr)
{
*n = MIN_CHUNK;
*lineptr = malloc (*n);
if (!*lineptr)
{
errno = ENOMEM;
return -1;
}
}
nchars_avail = *n - offset;
read_pos = *lineptr + offset;
for (;;)
{
int save_errno;
register int c = getc (stream);
save_errno = errno;
/* 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((*lineptr + *n) == (read_pos + nchars_avail));
if (nchars_avail < 2)
{
if (*n > MIN_CHUNK)
*n *= 2;
else
*n += MIN_CHUNK;
nchars_avail = *n + *lineptr - read_pos;
*lineptr = realloc (*lineptr, *n);
if (!*lineptr)
{
errno = ENOMEM;
return -1;
}
read_pos = *n - nchars_avail + *lineptr;
assert((*lineptr + *n) == (read_pos + nchars_avail));
}
if (ferror (stream))
{
/* Might like to return partial line, but there is no
place for us to store errno. And we don't want to just
lose errno. */
errno = save_errno;
return -1;
}
if (c == EOF)
{
/* 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';
ret = read_pos - (*lineptr + offset);
return ret;
}
int
getline (lineptr, n, stream)
char **lineptr;
size_t *n;
FILE *stream;
{
return getstr (lineptr, n, stream, '\n', 0);
}