In perl.git, the branch blead has been updated <http://perl5.git.perl.org/perl.git/commitdiff/e00e4ce90e17ff7101c36fc5496e8b2e353e7f7b?hp=57ad57e0c240e6f9b1b9e73de8068a9bc11b5466>
- Log ----------------------------------------------------------------- commit e00e4ce90e17ff7101c36fc5496e8b2e353e7f7b Author: brian d foy <[email protected]> Date: Fri Sep 25 15:17:39 2009 -0500 * Fix trailing whitespace in blead 778c687 M pod/perlfunc.pod commit 0f03d336cfac20781d0a45d83906fa559a5ecf17 Author: brian d foy <[email protected]> Date: Fri Sep 25 15:15:59 2009 -0500 RT #69208: Check eof before using readline in perlfunc readline example M pod/perlfunc.pod ----------------------------------------------------------------------- Summary of changes: pod/perlfunc.pod | 38 ++++++++++++++++++++++++-------------- 1 files changed, 24 insertions(+), 14 deletions(-) diff --git a/pod/perlfunc.pod b/pod/perlfunc.pod index 08c406c..bcf2b78 100644 --- a/pod/perlfunc.pod +++ b/pod/perlfunc.pod @@ -4332,12 +4332,12 @@ X<readline> X<gets> X<fgets> Reads from the filehandle whose typeglob is contained in EXPR (or from *ARGV if EXPR is not provided). In scalar context, each call reads and returns the next line, until end-of-file is reached, whereupon the -subsequent call returns undef. In list context, reads until end-of-file +subsequent call returns C<undef>. In list context, reads until end-of-file is reached and returns a list of lines. Note that the notion of "line" used here is however you may have defined it with C<$/> or C<$INPUT_RECORD_SEPARATOR>). See L<perlvar/"$/">. -When C<$/> is set to C<undef>, when readline() is in scalar +When C<$/> is set to C<undef>, when C<readline> is in scalar context (i.e. file slurp mode), and when an empty file is read, it returns C<''> the first time, followed by C<undef> subsequently. @@ -4348,19 +4348,29 @@ operator is discussed in more detail in L<perlop/"I/O Operators">. $line = <STDIN>; $line = readline(*STDIN); # same thing -If readline encounters an operating system error, C<$!> will be set with the -corresponding error message. It can be helpful to check C<$!> when you are -reading from filehandles you don't trust, such as a tty or a socket. The -following example uses the operator form of C<readline>, and takes the necessary -steps to ensure that C<readline> was successful. +If C<readline> encounters an operating system error, C<$!> will be set +with the corresponding error message. It can be helpful to check +C<$!> when you are reading from filehandles you don't trust, such as a +tty or a socket. The following example uses the operator form of +C<readline> and dies if the result is not defined. - for (;;) { - undef $!; - unless (defined( $line = <> )) { - last if eof; - die $! if $!; + while ( ! eof($fh) ) { + defined( $_ = <$fh> ) or die "readline failed: $!"; + ... + } + +Note that you have can't handle C<readline> errors that way with the +C<ARGV> filehandle. In that case, you have to open each element of +C<@ARGV> yourself since C<eof> handles C<ARGV> differently. + + foreach my $arg (@ARGV) { + open(my $fh, $arg) or warn "Can't open $arg: $!"; + + while ( ! eof($fh) ) { + defined( $_ = <$fh> ) + or die "readline failed for $arg: $!"; + ... } - # ... } =item readlink EXPR -- Perl5 Master Repository
