1 | package FileHandle;
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2 |
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3 | use 5.006;
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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 = "2.01";
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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 4
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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 a
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242 | list 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 a list 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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