/contrib/cvs/lib/getline.c
https://bitbucket.org/freebsd/freebsd-head/ · C · 174 lines · 112 code · 25 blank · 37 comment · 21 complexity · 8cdfb1910fe6f3ab4df66f52d6b7a692 MD5 · raw file
- /* 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>
- #include "getline.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). If LIMIT is non-negative, then
- read no more than LIMIT chars.
- *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, limit)
- char **lineptr;
- size_t *n;
- FILE *stream;
- int terminator;
- int offset;
- int limit;
- {
- 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;
- }
- *lineptr[0] = '\0';
- }
- nchars_avail = *n - offset;
- read_pos = *lineptr + offset;
- for (;;)
- {
- int save_errno;
- register int c;
- if (limit == 0)
- break;
- else
- {
- c = getc (stream);
- /* If limit is negative, then we shouldn't pay attention to
- it, so decrement only if positive. */
- if (limit > 0)
- limit--;
- }
- 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, GETLINE_NO_LIMIT);
- }
- int
- getline_safe (lineptr, n, stream, limit)
- char **lineptr;
- size_t *n;
- FILE *stream;
- int limit;
- {
- return getstr (lineptr, n, stream, '\n', 0, limit);
- }