1 | /* |
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2 | * Copyright (c) 1990, 2007 The Regents of the University of California. |
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3 | * All rights reserved. |
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4 | * |
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5 | * Redistribution and use in source and binary forms are permitted |
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6 | * provided that the above copyright notice and this paragraph are |
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7 | * duplicated in all such forms and that any documentation, |
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8 | * advertising materials, and other materials related to such |
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9 | * distribution and use acknowledge that the software was developed |
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10 | * by the University of California, Berkeley. The name of the |
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11 | * University may not be used to endorse or promote products derived |
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12 | * from this software without specific prior written permission. |
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13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
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14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
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15 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
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16 | */ |
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17 | /* No user fns here. Pesch 15apr92. */ |
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18 | |
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19 | #include <_ansi.h> |
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20 | #include <stdio.h> |
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21 | #include <stdlib.h> |
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22 | #include <sys/stat.h> |
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23 | #include <sys/types.h> |
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24 | #include <sys/unistd.h> |
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25 | #include "local.h" |
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26 | |
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27 | #define _DEFAULT_ASPRINTF_BUFSIZE 64 |
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28 | |
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29 | /* |
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30 | * Allocate a file buffer, or switch to unbuffered I/O. |
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31 | * Per the ANSI C standard, ALL tty devices default to line buffered. |
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32 | * |
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33 | * As a side effect, we set __SOPT or __SNPT (en/dis-able fseek |
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34 | * optimization) right after the _fstat() that finds the buffer size. |
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35 | */ |
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36 | |
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37 | void |
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38 | __smakebuf_r (struct _reent *ptr, |
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39 | register FILE *fp) |
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40 | { |
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41 | register void *p; |
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42 | int flags; |
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43 | size_t size; |
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44 | int couldbetty; |
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45 | |
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46 | if (fp->_flags & __SNBF) |
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47 | { |
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48 | fp->_bf._base = fp->_p = fp->_nbuf; |
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49 | fp->_bf._size = 1; |
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50 | return; |
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51 | } |
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52 | flags = __swhatbuf_r (ptr, fp, &size, &couldbetty); |
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53 | if ((p = _malloc_r (ptr, size)) == NULL) |
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54 | { |
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55 | if (!(fp->_flags & __SSTR)) |
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56 | { |
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57 | fp->_flags = (fp->_flags & ~__SLBF) | __SNBF; |
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58 | fp->_bf._base = fp->_p = fp->_nbuf; |
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59 | fp->_bf._size = 1; |
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60 | } |
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61 | } |
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62 | else |
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63 | { |
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64 | ptr->__cleanup = _cleanup_r; |
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65 | fp->_flags |= __SMBF; |
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66 | fp->_bf._base = fp->_p = (unsigned char *) p; |
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67 | fp->_bf._size = size; |
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68 | if (couldbetty && _isatty_r (ptr, fp->_file)) |
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69 | fp->_flags = (fp->_flags & ~__SNBF) | __SLBF; |
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70 | fp->_flags |= flags; |
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71 | } |
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72 | } |
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73 | |
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74 | /* |
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75 | * Internal routine to determine `proper' buffering for a file. |
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76 | */ |
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77 | int |
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78 | __swhatbuf_r (struct _reent *ptr, |
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79 | FILE *fp, |
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80 | size_t *bufsize, |
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81 | int *couldbetty) |
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82 | { |
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83 | #ifdef _FSEEK_OPTIMIZATION |
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84 | const int snpt = __SNPT; |
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85 | #else |
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86 | const int snpt = 0; |
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87 | #endif |
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88 | |
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89 | #ifdef __USE_INTERNAL_STAT64 |
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90 | struct stat64 st; |
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91 | |
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92 | if (fp->_file < 0 || _fstat64_r (ptr, fp->_file, &st) < 0) |
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93 | #else |
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94 | struct stat st; |
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95 | |
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96 | if (fp->_file < 0 || _fstat_r (ptr, fp->_file, &st) < 0) |
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97 | #endif |
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98 | { |
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99 | *couldbetty = 0; |
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100 | /* Check if we are be called by asprintf family for initial buffer. */ |
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101 | if (fp->_flags & __SMBF) |
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102 | *bufsize = _DEFAULT_ASPRINTF_BUFSIZE; |
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103 | else |
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104 | *bufsize = BUFSIZ; |
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105 | return (0); |
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106 | } |
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107 | |
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108 | /* could be a tty iff it is a character device */ |
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109 | *couldbetty = S_ISCHR(st.st_mode); |
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110 | #ifdef HAVE_BLKSIZE |
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111 | if (st.st_blksize > 0) |
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112 | { |
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113 | /* |
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114 | * Optimise fseek() only if it is a regular file. (The test for |
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115 | * __sseek is mainly paranoia.) It is safe to set _blksize |
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116 | * unconditionally; it will only be used if __SOPT is also set. |
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117 | */ |
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118 | *bufsize = st.st_blksize; |
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119 | fp->_blksize = st.st_blksize; |
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120 | return ((st.st_mode & S_IFMT) == S_IFREG ? __SOPT : snpt); |
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121 | } |
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122 | #endif |
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123 | *bufsize = BUFSIZ; |
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124 | return (snpt); |
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125 | } |
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