Annotation of prex/usr/lib/libc/stdio/findfp.c, Revision 1.1.1.1
1.1 nbrk 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. Neither the name of the University nor the names of its contributors
17: * may be used to endorse or promote products derived from this software
18: * without specific prior written permission.
19: *
20: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30: * SUCH DAMAGE.
31: */
32:
33: #include <sys/param.h>
34: #include <unistd.h>
35: #include <stdio.h>
36: #include <stdlib.h>
37: #include <errno.h>
38: #include <string.h>
39: #include "local.h"
40:
41: int __sdidinit;
42:
43: #define std(next, flags, file) \
44: {next,NULL,0,0,flags,file,{0,0},{0,0},NULL,0,{0},{0}}
45: /* p r w flags file _bf z */
46:
47: FILE __sF[3] = {
48: std(&__sF[1], __SRD, STDIN_FILENO),
49: std(&__sF[2], __SWR, STDOUT_FILENO),
50: std(NULL, __SWR|__SNBF, STDERR_FILENO)
51: };
52:
53: /*
54: * Find a free FILE for fopen et al.
55: */
56: FILE *
57: __sfp()
58: {
59: FILE *fp, *tmp;
60:
61: if (!__sdidinit)
62: __sinit();
63: for (fp = &__sF[0];; fp = fp->next) {
64: if (fp->_flags == 0)
65: goto found;
66: if (fp->next == NULL) {
67: if ((tmp = malloc(sizeof(FILE))) == NULL)
68: break;
69: tmp->next = NULL;
70: fp->next = tmp;
71: fp = tmp;
72: goto found;
73: }
74: }
75: return (NULL);
76: found:
77: fp->_flags = 1; /* reserve this slot; caller sets real flags */
78: fp->_p = NULL; /* no current pointer */
79: fp->_w = 0; /* nothing to read or write */
80: fp->_r = 0;
81: fp->_bf._base = NULL; /* no buffer */
82: fp->_bf._size = 0;
83: fp->_file = -1; /* no file */
84: fp->_ub._base = NULL; /* no ungetc buffer */
85: fp->_ub._size = 0;
86: return (fp);
87: }
88:
89: /*
90: * exit() calls _cleanup() through *__cleanup, set whenever we
91: * open or buffer a file. This chicanery is done so that programs
92: * that do not use stdio need not link it all in.
93: *
94: * The name `_cleanup' is, alas, fairly well known outside stdio.
95: b */
96: void
97: _cleanup()
98: {
99: /* (void) _fwalk(fclose); */
100: (void) _fwalk(__sflush); /* `cheating' */
101: }
102:
103: /*
104: * __sinit() is called whenever stdio's internal variables must be set up.
105: */
106: void
107: __sinit()
108: {
109: /* make sure we clean up on exit */
110: __cleanup = _cleanup; /* conservative */
111: __sdidinit = 1;
112: }
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