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2aa62f2b | 1 | /** @file\r |
2 | Implementation of freopen as declared in <stdio.h>.\r | |
3 | \r | |
53e1e5c6 | 4 | Copyright (c) 2010 - 2011, Intel Corporation. All rights reserved.<BR>\r |
2aa62f2b | 5 | This program and the accompanying materials are licensed and made available\r |
6 | under the terms and conditions of the BSD License that accompanies this\r | |
7 | distribution. The full text of the license may be found at\r | |
53e1e5c6 | 8 | http://opensource.org/licenses/bsd-license.\r |
2aa62f2b | 9 | \r |
10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
12 | \r | |
13 | Copyright (c) 1990, 1993\r | |
14 | The Regents of the University of California. All rights reserved.\r | |
15 | \r | |
16 | This code is derived from software contributed to Berkeley by\r | |
17 | Chris Torek.\r | |
18 | \r | |
19 | Redistribution and use in source and binary forms, with or without\r | |
20 | modification, are permitted provided that the following conditions\r | |
21 | are met:\r | |
22 | - Redistributions of source code must retain the above copyright\r | |
23 | notice, this list of conditions and the following disclaimer.\r | |
24 | - Redistributions in binary form must reproduce the above copyright\r | |
25 | notice, this list of conditions and the following disclaimer in the\r | |
26 | documentation and/or other materials provided with the distribution.\r | |
27 | - Neither the name of the University nor the names of its contributors\r | |
28 | may be used to endorse or promote products derived from this software\r | |
29 | without specific prior written permission.\r | |
30 | \r | |
31 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"\r | |
32 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE\r | |
33 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE\r | |
34 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE\r | |
35 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR\r | |
36 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF\r | |
37 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS\r | |
38 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN\r | |
39 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)\r | |
40 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE\r | |
41 | POSSIBILITY OF SUCH DAMAGE.\r | |
42 | \r | |
43 | NetBSD: freopen.c,v 1.14 2003/08/07 16:43:25 agc Exp\r | |
44 | freopen.c 8.1 (Berkeley) 6/4/93\r | |
45 | **/\r | |
46 | #include <LibConfig.h>\r | |
47 | #include <sys/EfiCdefs.h>\r | |
48 | \r | |
49 | #include <sys/types.h>\r | |
50 | #include <sys/stat.h>\r | |
51 | \r | |
52 | #include <assert.h>\r | |
53 | #include <errno.h>\r | |
54 | #include <fcntl.h>\r | |
2aa62f2b | 55 | #include <stdio.h>\r |
56 | #include <stdlib.h>\r | |
57 | #include <wchar.h>\r | |
0c1992fb | 58 | #include <unistd.h>\r |
2aa62f2b | 59 | #include "reentrant.h"\r |
60 | #include "local.h"\r | |
61 | \r | |
62 | /*\r | |
63 | * Re-direct an existing, open (probably) file to some other file.\r | |
64 | * ANSI is written such that the original file gets closed if at\r | |
65 | * all possible, no matter what.\r | |
66 | */\r | |
67 | FILE *\r | |
68 | freopen(const char *file, const char *mode, FILE *fp)\r | |
69 | {\r | |
70 | int f;\r | |
71 | int flags, isopen, oflags, sverrno, wantfd;\r | |
72 | \r | |
73 | _DIAGASSERT(file != NULL);\r | |
74 | _DIAGASSERT(mode != NULL);\r | |
75 | _DIAGASSERT(fp != NULL);\r | |
53e1e5c6 | 76 | if(fp == NULL) {\r |
77 | errno = EINVAL;\r | |
78 | return (NULL);\r | |
79 | }\r | |
2aa62f2b | 80 | \r |
81 | if ((flags = __sflags(mode, &oflags)) == 0) {\r | |
82 | (void) fclose(fp);\r | |
83 | return (NULL);\r | |
84 | }\r | |
85 | \r | |
86 | if (!__sdidinit)\r | |
87 | __sinit();\r | |
88 | \r | |
89 | /*\r | |
90 | * There are actually programs that depend on being able to "freopen"\r | |
91 | * descriptors that weren't originally open. Keep this from breaking.\r | |
92 | * Remember whether the stream was open to begin with, and which file\r | |
93 | * descriptor (if any) was associated with it. If it was attached to\r | |
94 | * a descriptor, defer closing it; freopen("/dev/stdin", "r", stdin)\r | |
95 | * should work. This is unnecessary if it was not a Unix file.\r | |
96 | */\r | |
97 | if (fp->_flags == 0) {\r | |
98 | fp->_flags = __SEOF; /* hold on to it */\r | |
99 | isopen = 0;\r | |
100 | wantfd = -1;\r | |
101 | } else {\r | |
102 | /* flush the stream; ANSI doesn't require this. */\r | |
103 | if (fp->_flags & __SWR)\r | |
104 | (void) __sflush(fp);\r | |
105 | /* if close is NULL, closing is a no-op, hence pointless */\r | |
106 | isopen = fp->_close != NULL;\r | |
d7ce7006 | 107 | if (((wantfd = fp->_file) >= 0) && isopen) {\r |
2aa62f2b | 108 | (void) (*fp->_close)(fp->_cookie);\r |
109 | isopen = 0;\r | |
110 | }\r | |
111 | }\r | |
112 | \r | |
113 | /* Get a new descriptor to refer to the new file. */\r | |
114 | f = open(file, oflags, DEFFILEMODE);\r | |
115 | if (f < 0 && isopen) {\r | |
116 | /* If out of fd's close the old one and try again. */\r | |
117 | if (errno == ENFILE || errno == EMFILE) {\r | |
118 | (void) (*fp->_close)(fp->_cookie);\r | |
119 | isopen = 0;\r | |
120 | f = open(file, oflags, DEFFILEMODE);\r | |
121 | }\r | |
122 | }\r | |
123 | sverrno = errno;\r | |
124 | \r | |
125 | /*\r | |
126 | * Finish closing fp. Even if the open succeeded above, we cannot\r | |
127 | * keep fp->_base: it may be the wrong size. This loses the effect\r | |
128 | * of any setbuffer calls, but stdio has always done this before.\r | |
129 | */\r | |
d7ce7006 | 130 | if (isopen && (f != wantfd))\r |
2aa62f2b | 131 | (void) (*fp->_close)(fp->_cookie);\r |
132 | if (fp->_flags & __SMBF)\r | |
133 | free((char *)fp->_bf._base);\r | |
134 | fp->_w = 0;\r | |
135 | fp->_r = 0;\r | |
136 | fp->_p = NULL;\r | |
137 | fp->_bf._base = NULL;\r | |
138 | fp->_bf._size = 0;\r | |
139 | fp->_lbfsize = 0;\r | |
140 | if (HASUB(fp))\r | |
141 | FREEUB(fp);\r | |
142 | WCIO_FREE(fp);\r | |
143 | _UB(fp)._size = 0;\r | |
144 | if (HASLB(fp))\r | |
145 | FREELB(fp);\r | |
146 | fp->_lb._size = 0;\r | |
147 | \r | |
148 | if (f < 0) { /* did not get it after all */\r | |
149 | fp->_flags = 0; /* set it free */\r | |
150 | errno = sverrno; /* restore in case _close clobbered */\r | |
151 | return (NULL);\r | |
152 | }\r | |
153 | \r | |
154 | if (oflags & O_NONBLOCK) {\r | |
155 | struct stat st;\r | |
156 | if (fstat(f, &st) == -1) {\r | |
157 | sverrno = errno;\r | |
158 | (void)close(f);\r | |
159 | errno = sverrno;\r | |
160 | return (NULL);\r | |
161 | }\r | |
162 | if (!S_ISREG(st.st_mode)) {\r | |
163 | (void)close(f);\r | |
164 | errno = EFTYPE;\r | |
165 | return (NULL);\r | |
166 | }\r | |
167 | }\r | |
168 | \r | |
169 | /*\r | |
170 | * If reopening something that was open before on a real file, try\r | |
171 | * to maintain the descriptor. Various C library routines (perror)\r | |
172 | * assume stderr is always fd STDERR_FILENO, even if being freopen'd.\r | |
173 | */\r | |
174 | if (wantfd >= 0 && f != wantfd) {\r | |
175 | if (dup2(f, wantfd) >= 0) {\r | |
176 | (void) close(f);\r | |
177 | f = wantfd;\r | |
178 | }\r | |
179 | }\r | |
180 | \r | |
181 | fp->_flags = (unsigned short)flags;\r | |
182 | fp->_file = (short)f;\r | |
183 | fp->_cookie = fp;\r | |
184 | fp->_read = __sread;\r | |
185 | fp->_write = __swrite;\r | |
186 | fp->_seek = __sseek;\r | |
187 | fp->_close = __sclose;\r | |
188 | \r | |
189 | /*\r | |
190 | * When reopening in append mode, even though we use O_APPEND,\r | |
191 | * we need to seek to the end so that ftell() gets the right\r | |
192 | * answer. If the user then alters the seek pointer, or\r | |
193 | * the file extends, this will fail, but there is not much\r | |
194 | * we can do about this. (We could set __SAPP and check in\r | |
195 | * fseek and ftell.)\r | |
196 | */\r | |
197 | if (oflags & O_APPEND)\r | |
198 | (void) __sseek((void *)fp, (fpos_t)0, SEEK_END);\r | |
199 | return (fp);\r | |
200 | }\r |