xref: /haiku/src/system/libroot/posix/glibc/libio/iogetdelim.c (revision 17889a8c70dbb3d59c1412f6431968753c767bab)
1 /* Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, write to the Free
16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17    02111-1307 USA.
18 
19    As a special exception, if you link the code in this file with
20    files compiled with a GNU compiler to produce an executable,
21    that does not cause the resulting executable to be covered by
22    the GNU Lesser General Public License.  This exception does not
23    however invalidate any other reasons why the executable file
24    might be covered by the GNU Lesser General Public License.
25    This exception applies to code released by its copyright holders
26    in files containing the exception.
27 */
28 
29 #include "libioP.h"
30 #include <stdlib.h>
31 #include <string.h>
32 #include <errno.h>
33 
34 /* Read up to (and including) a TERMINATOR from FP into *LINEPTR
35    (and null-terminate it).  *LINEPTR is a pointer returned from malloc (or
36    NULL), pointing to *N characters of space.  It is realloc'ed as
37    necessary.  Returns the number of characters read (not including the
38    null terminator), or -1 on error or EOF.  */
39 
40 _IO_ssize_t
41 _IO_getdelim(char **lineptr, _IO_size_t *n, int delimiter, _IO_FILE *fp)
42 {
43   int result;
44   _IO_ssize_t cur_len = 0;
45   _IO_ssize_t len;
46 
47   if (lineptr == NULL || n == NULL)
48     {
49       MAYBE_SET_EINVAL;
50       return -1;
51     }
52   CHECK_FILE (fp, -1);
53   _IO_cleanup_region_start ((void (*) __P ((void *))) _IO_funlockfile, fp);
54   _IO_flockfile (fp);
55   if (_IO_ferror_unlocked (fp))
56     {
57       result = -1;
58       goto unlock_return;
59     }
60 
61   if (*lineptr == NULL || *n == 0)
62     {
63       *n = 120;
64       *lineptr = (char *) malloc (*n);
65       if (*lineptr == NULL)
66 	{
67 	  result = -1;
68 	  goto unlock_return;
69 	}
70     }
71 
72   len = fp->_IO_read_end - fp->_IO_read_ptr;
73   if (len <= 0)
74     {
75       if (__underflow (fp) == EOF)
76 	{
77 	  result = -1;
78 	  goto unlock_return;
79 	}
80       len = fp->_IO_read_end - fp->_IO_read_ptr;
81     }
82 
83   for (;;)
84     {
85       _IO_size_t needed;
86       char *t;
87       t = (char *) memchr ((void *) fp->_IO_read_ptr, delimiter, len);
88       if (t != NULL)
89 	len = (t - fp->_IO_read_ptr) + 1;
90       /* Make enough space for len+1 (for final NUL) bytes.  */
91       needed = cur_len + len + 1;
92       if (needed > *n)
93 	{
94 	  char *new_lineptr;
95 
96 	  if (needed < 2 * *n)
97 	    needed = 2 * *n;  /* Be generous. */
98 	  new_lineptr = (char *) realloc (*lineptr, needed);
99 	  if (new_lineptr == NULL)
100 	    {
101 	      result = -1;
102 	      goto unlock_return;
103 	    }
104 	  *lineptr = new_lineptr;
105 	  *n = needed;
106 	}
107       memcpy (*lineptr + cur_len, (void *) fp->_IO_read_ptr, len);
108       fp->_IO_read_ptr += len;
109       cur_len += len;
110       if (t != NULL || __underflow (fp) == EOF)
111 	break;
112       len = fp->_IO_read_end - fp->_IO_read_ptr;
113     }
114   (*lineptr)[cur_len] = '\0';
115   result = cur_len;
116 
117 unlock_return:
118   _IO_funlockfile (fp);
119   _IO_cleanup_region_end (0);
120   return result;
121 }
122 
123 #ifdef weak_alias
124 weak_alias (_IO_getdelim, __getdelim)
125 weak_alias (_IO_getdelim, getdelim)
126 #endif
127