1 | package FileHandle; |
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2 | |
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3 | use 5.005_64; |
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4 | use strict; |
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5 | our($VERSION, @ISA, @EXPORT, @EXPORT_OK); |
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6 | |
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7 | $VERSION = "2.00"; |
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8 | |
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9 | require IO::File; |
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10 | @ISA = qw(IO::File); |
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11 | |
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12 | @EXPORT = qw(_IOFBF _IOLBF _IONBF); |
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13 | |
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14 | @EXPORT_OK = qw( |
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15 | pipe |
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16 | |
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17 | autoflush |
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18 | output_field_separator |
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19 | output_record_separator |
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20 | input_record_separator |
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21 | input_line_number |
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22 | format_page_number |
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23 | format_lines_per_page |
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24 | format_lines_left |
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25 | format_name |
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26 | format_top_name |
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27 | format_line_break_characters |
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28 | format_formfeed |
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29 | |
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30 | print |
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31 | printf |
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32 | getline |
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33 | getlines |
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34 | ); |
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35 | |
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36 | # |
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37 | # Everything we're willing to export, we must first import. |
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38 | # |
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39 | import IO::Handle grep { !defined(&$_) } @EXPORT, @EXPORT_OK; |
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40 | |
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41 | # |
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42 | # Some people call "FileHandle::function", so all the functions |
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43 | # that were in the old FileHandle class must be imported, too. |
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44 | # |
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45 | { |
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46 | no strict 'refs'; |
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47 | |
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48 | my %import = ( |
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49 | 'IO::Handle' => |
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50 | [qw(DESTROY new_from_fd fdopen close fileno getc ungetc gets |
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51 | eof flush error clearerr setbuf setvbuf _open_mode_string)], |
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52 | 'IO::Seekable' => |
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53 | [qw(seek tell getpos setpos)], |
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54 | 'IO::File' => |
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55 | [qw(new new_tmpfile open)] |
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56 | ); |
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57 | for my $pkg (keys %import) { |
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58 | for my $func (@{$import{$pkg}}) { |
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59 | my $c = *{"${pkg}::$func"}{CODE} |
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60 | or die "${pkg}::$func missing"; |
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61 | *$func = $c; |
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62 | } |
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63 | } |
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64 | } |
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65 | |
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66 | # |
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67 | # Specialized importer for Fcntl magic. |
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68 | # |
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69 | sub import { |
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70 | my $pkg = shift; |
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71 | my $callpkg = caller; |
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72 | require Exporter; |
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73 | Exporter::export($pkg, $callpkg, @_); |
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74 | |
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75 | # |
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76 | # If the Fcntl extension is available, |
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77 | # export its constants. |
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78 | # |
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79 | eval { |
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80 | require Fcntl; |
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81 | Exporter::export('Fcntl', $callpkg); |
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82 | }; |
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83 | } |
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84 | |
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85 | ################################################ |
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86 | # This is the only exported function we define; |
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87 | # the rest come from other classes. |
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88 | # |
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89 | |
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90 | sub pipe { |
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91 | my $r = new IO::Handle; |
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92 | my $w = new IO::Handle; |
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93 | CORE::pipe($r, $w) or return undef; |
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94 | ($r, $w); |
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95 | } |
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96 | |
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97 | # Rebless standard file handles |
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98 | bless *STDIN{IO}, "FileHandle" if ref *STDIN{IO} eq "IO::Handle"; |
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99 | bless *STDOUT{IO}, "FileHandle" if ref *STDOUT{IO} eq "IO::Handle"; |
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100 | bless *STDERR{IO}, "FileHandle" if ref *STDERR{IO} eq "IO::Handle"; |
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101 | |
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102 | 1; |
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103 | |
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104 | __END__ |
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105 | |
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106 | =head1 NAME |
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107 | |
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108 | FileHandle - supply object methods for filehandles |
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109 | |
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110 | =head1 SYNOPSIS |
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111 | |
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112 | use FileHandle; |
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113 | |
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114 | $fh = new FileHandle; |
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115 | if ($fh->open("< file")) { |
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116 | print <$fh>; |
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117 | $fh->close; |
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118 | } |
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119 | |
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120 | $fh = new FileHandle "> FOO"; |
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121 | if (defined $fh) { |
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122 | print $fh "bar\n"; |
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123 | $fh->close; |
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124 | } |
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125 | |
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126 | $fh = new FileHandle "file", "r"; |
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127 | if (defined $fh) { |
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128 | print <$fh>; |
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129 | undef $fh; # automatically closes the file |
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130 | } |
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131 | |
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132 | $fh = new FileHandle "file", O_WRONLY|O_APPEND; |
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133 | if (defined $fh) { |
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134 | print $fh "corge\n"; |
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135 | undef $fh; # automatically closes the file |
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136 | } |
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137 | |
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138 | $pos = $fh->getpos; |
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139 | $fh->setpos($pos); |
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140 | |
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141 | $fh->setvbuf($buffer_var, _IOLBF, 1024); |
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142 | |
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143 | ($readfh, $writefh) = FileHandle::pipe; |
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144 | |
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145 | autoflush STDOUT 1; |
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146 | |
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147 | =head1 DESCRIPTION |
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148 | |
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149 | NOTE: This class is now a front-end to the IO::* classes. |
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150 | |
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151 | C<FileHandle::new> creates a C<FileHandle>, which is a reference to a |
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152 | newly created symbol (see the C<Symbol> package). If it receives any |
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153 | parameters, they are passed to C<FileHandle::open>; if the open fails, |
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154 | the C<FileHandle> object is destroyed. Otherwise, it is returned to |
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155 | the caller. |
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156 | |
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157 | C<FileHandle::new_from_fd> creates a C<FileHandle> like C<new> does. |
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158 | It requires two parameters, which are passed to C<FileHandle::fdopen>; |
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159 | if the fdopen fails, the C<FileHandle> object is destroyed. |
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160 | Otherwise, it is returned to the caller. |
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161 | |
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162 | C<FileHandle::open> accepts one parameter or two. With one parameter, |
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163 | it is just a front end for the built-in C<open> function. With two |
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164 | parameters, the first parameter is a filename that may include |
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165 | whitespace or other special characters, and the second parameter is |
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166 | the open mode, optionally followed by a file permission value. |
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167 | |
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168 | If C<FileHandle::open> receives a Perl mode string (">", "+<", etc.) |
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169 | or a POSIX fopen() mode string ("w", "r+", etc.), it uses the basic |
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170 | Perl C<open> operator. |
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171 | |
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172 | If C<FileHandle::open> is given a numeric mode, it passes that mode |
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173 | and the optional permissions value to the Perl C<sysopen> operator. |
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174 | For convenience, C<FileHandle::import> tries to import the O_XXX |
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175 | constants from the Fcntl module. If dynamic loading is not available, |
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176 | this may fail, but the rest of FileHandle will still work. |
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177 | |
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178 | C<FileHandle::fdopen> is like C<open> except that its first parameter |
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179 | is not a filename but rather a file handle name, a FileHandle object, |
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180 | or a file descriptor number. |
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181 | |
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182 | If the C functions fgetpos() and fsetpos() are available, then |
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183 | C<FileHandle::getpos> returns an opaque value that represents the |
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184 | current position of the FileHandle, and C<FileHandle::setpos> uses |
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185 | that value to return to a previously visited position. |
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186 | |
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187 | If the C function setvbuf() is available, then C<FileHandle::setvbuf> |
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188 | sets the buffering policy for the FileHandle. The calling sequence |
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189 | for the Perl function is the same as its C counterpart, including the |
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190 | macros C<_IOFBF>, C<_IOLBF>, and C<_IONBF>, except that the buffer |
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191 | parameter specifies a scalar variable to use as a buffer. WARNING: A |
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192 | variable used as a buffer by C<FileHandle::setvbuf> must not be |
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193 | modified in any way until the FileHandle is closed or until |
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194 | C<FileHandle::setvbuf> is called again, or memory corruption may |
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195 | result! |
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196 | |
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197 | See L<perlfunc> for complete descriptions of each of the following |
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198 | supported C<FileHandle> methods, which are just front ends for the |
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199 | corresponding built-in functions: |
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200 | |
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201 | close |
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202 | fileno |
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203 | getc |
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204 | gets |
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205 | eof |
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206 | clearerr |
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207 | seek |
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208 | tell |
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209 | |
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210 | See L<perlvar> for complete descriptions of each of the following |
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211 | supported C<FileHandle> methods: |
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212 | |
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213 | autoflush |
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214 | output_field_separator |
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215 | output_record_separator |
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216 | input_record_separator |
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217 | input_line_number |
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218 | format_page_number |
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219 | format_lines_per_page |
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220 | format_lines_left |
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221 | format_name |
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222 | format_top_name |
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223 | format_line_break_characters |
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224 | format_formfeed |
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225 | |
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226 | Furthermore, for doing normal I/O you might need these: |
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227 | |
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228 | =over |
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229 | |
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230 | =item $fh->print |
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231 | |
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232 | See L<perlfunc/print>. |
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233 | |
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234 | =item $fh->printf |
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235 | |
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236 | See L<perlfunc/printf>. |
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237 | |
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238 | =item $fh->getline |
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239 | |
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240 | This works like <$fh> described in L<perlop/"I/O Operators"> |
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241 | except that it's more readable and can be safely called in an |
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242 | array context but still returns just one line. |
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243 | |
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244 | =item $fh->getlines |
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245 | |
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246 | This works like <$fh> when called in an array context to |
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247 | read all the remaining lines in a file, except that it's more readable. |
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248 | It will also croak() if accidentally called in a scalar context. |
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249 | |
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250 | =back |
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251 | |
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252 | There are many other functions available since FileHandle is descended |
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253 | from IO::File, IO::Seekable, and IO::Handle. Please see those |
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254 | respective pages for documentation on more functions. |
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255 | |
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256 | =head1 SEE ALSO |
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257 | |
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258 | The B<IO> extension, |
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259 | L<perlfunc>, |
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260 | L<perlop/"I/O Operators">. |
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261 | |
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262 | =cut |
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