findfp.c - vx32 - Local 9vx git repository for patches.
(HTM) git clone git://r-36.net/vx32
(DIR) Log
(DIR) Files
(DIR) Refs
---
findfp.c (4610B)
---
1 /*-
2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Chris Torek.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #if defined(LIBC_SCCS) && !defined(lint)
38 static char rcsid[] = "$OpenBSD: findfp.c,v 1.2 1996/08/19 08:32:36 tholo Exp $";
39 #endif /* LIBC_SCCS and not lint */
40
41 #include <unistd.h>
42 #include <stdio.h>
43 #include <errno.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include "local.h"
47 #include "glue.h"
48
49 int __sdidinit;
50
51 #define NDYNAMIC 10 /* add ten more whenever necessary */
52
53 #define std(flags, file) \
54 {0,0,0,flags,file,{0},0,__sF+file,__sclose,__sread,__sseek,__swrite}
55 /* p r w flags file _bf z cookie close read seek write */
56
57 /* the usual - (stdin + stdout + stderr) */
58 static FILE usual[FOPEN_MAX - 3];
59 static struct glue uglue = { 0, FOPEN_MAX - 3, usual };
60
61 FILE __sF[3] = {
62 std(__SRD, STDIN_FILENO), /* stdin */
63 std(__SWR, STDOUT_FILENO), /* stdout */
64 std(__SWR|__SNBF, STDERR_FILENO) /* stderr */
65 };
66 struct glue __sglue = { &uglue, 3, __sF };
67
68 static struct glue *
69 moreglue(n)
70 register int n;
71 {
72 register struct glue *g;
73 register FILE *p;
74 static FILE empty;
75
76 g = (struct glue *)malloc(sizeof(*g) + n * sizeof(FILE));
77 if (g == NULL)
78 return (NULL);
79 p = (FILE *)(g+1);
80 g->next = NULL;
81 g->niobs = n;
82 g->iobs = p;
83 while (--n >= 0)
84 *p++ = empty;
85 return (g);
86 }
87
88 /*
89 * Find a free FILE for fopen et al.
90 */
91 FILE *
92 __sfp()
93 {
94 register FILE *fp;
95 register int n;
96 register struct glue *g;
97
98 if (!__sdidinit)
99 __sinit();
100 for (g = &__sglue;; g = g->next) {
101 for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
102 if (fp->_flags == 0)
103 goto found;
104 if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL)
105 break;
106 }
107 return (NULL);
108 found:
109 fp->_flags = 1; /* reserve this slot; caller sets real flags */
110 fp->_p = NULL; /* no current pointer */
111 fp->_w = 0; /* nothing to read or write */
112 fp->_r = 0;
113 fp->_bf._base = NULL; /* no buffer */
114 fp->_bf._size = 0;
115 fp->_lbfsize = 0; /* not line buffered */
116 fp->_file = -1; /* no file */
117 /* fp->_cookie = <any>; */ /* caller sets cookie, _read/_write etc */
118 fp->_ub._base = NULL; /* no ungetc buffer */
119 fp->_ub._size = 0;
120 fp->_lb._base = NULL; /* no line buffer */
121 fp->_lb._size = 0;
122 return (fp);
123 }
124
125 /*
126 * exit() calls _cleanup() through *__cleanup, set whenever we
127 * open or buffer a file. This chicanery is done so that programs
128 * that do not use stdio need not link it all in.
129 *
130 * The name `_cleanup' is, alas, fairly well known outside stdio.
131 */
132 void
133 _cleanup()
134 {
135 /* (void) _fwalk(fclose); */
136 (void) _fwalk(__sflush); /* `cheating' */
137 }
138
139 /*
140 * __sinit() is called whenever stdio's internal variables must be set up.
141 */
142 void
143 __sinit()
144 {
145 extern void (*__exit_flush)(void);
146
147 /* make sure we clean up on exit */
148 __exit_flush = _cleanup; /* conservative */
149 __sdidinit = 1;
150 }