usr/src/lib/libc/port/stdio/getline.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
  24  */
  25
  26 #include "lint.h"
  27 #include "file64.h"
  28 #include "mtlib.h"
  29 #include <stdio.h>
  30 #include <errno.h>
  31 #include <thread.h>
  32 #include <synch.h>
  33 #include <unistd.h>
  34 #include <limits.h>
  35 #include <malloc.h>
  36 #include <sys/types.h>
  37 #include "stdiom.h"
  38
  39 #define LINESZ  128     /* initial guess for a NULL *lineptr */
  40
  41 ssize_t
  42 getdelim(char **_RESTRICT_KYWD lineptr, size_t *_RESTRICT_KYWD n,
  43     int delimiter, FILE *_RESTRICT_KYWD iop)
  44 {
  45         rmutex_t *lk;
  46         char *ptr;
  47         size_t size;
  48         int c;
  49         size_t cnt;
  50
  51         if (lineptr == NULL || n == NULL ||
  52             delimiter < 0 || delimiter > UCHAR_MAX) {
  53                 errno = EINVAL;
  54                 return (-1);
  55         }
  56
  57         if (*lineptr == NULL || *n < LINESZ) {  /* initial allocation */
  58                 if ((*lineptr = realloc(*lineptr, LINESZ)) == NULL) {
  59                         errno = ENOMEM;
  60                         return (-1);
  61                 }
  62                 *n = LINESZ;
  63         }
  64         ptr = *lineptr;
  65         size = *n;
  66         cnt = 0;
  67
  68         FLOCKFILE(lk, iop);
  69
  70         _SET_ORIENTATION_BYTE(iop);
  71
  72         do {
  73                 c = (--iop->_cnt < 0) ? __filbuf(iop) : *iop->_ptr++;
  74                 if (c == EOF)
  75                         break;
  76                 *ptr++ = c;
  77                 if (++cnt == size) {    /* must reallocate */
  78                         if ((ptr = realloc(*lineptr, 2 * size)) == NULL) {
  79                                 FUNLOCKFILE(lk);
  80                                 ptr = *lineptr + size - 1;
  81                                 *ptr = '\0';
  82                                 errno = ENOMEM;
  83                                 return (-1);
  84                         }
  85                         *lineptr = ptr;
  86                         ptr += size;
  87                         *n = size = 2 * size;
  88                 }
  89         } while (c != delimiter);
  90
  91         *ptr = '\0';
  92
  93         FUNLOCKFILE(lk);
  94         if (cnt > SSIZE_MAX) {
  95                 errno = EOVERFLOW;
  96                 return (-1);
  97         }
  98         return (cnt ? cnt : -1);
  99 }
 100
 101 ssize_t
 102 getline(char **_RESTRICT_KYWD lineptr, size_t *_RESTRICT_KYWD n,
 103     FILE *_RESTRICT_KYWD iop)
 104 {
 105         return (getdelim(lineptr, n, '\n', iop));
 106 }