Thank you all. It will take a day or two to get through all of this
Sherman
On Tue, May 7, 2013 at 1:52 PM, Jim Gibson <jimsgib...@gmail.com> wrote:
>
> On May 7, 2013, at 11:00 AM, Sherman Willden wrote:
>
> > Lines written to a file are not contiguous.
> >
> > First I will describe what I want the script to perform and then I will
> include the script at the end of this message. I downloaded the Oreilly
> Programming Perl Version 4 examples. There are 30 directories with 2211
> files. I want each chapter to have a consolidated file with all the
> examples for that chapter. I created the
> > consolidate_examples.pl
> > script which goes into each directory, reads each file, and then writes
> the files lines to the consolidated_perl4_examples/<directory name>. An
> example is consolidated_perl4_examples/ch00_preface with contains six
> lines. ch27_perl_functions is the largest and has 435 files which results
> in a single file with 870 lines. What I expected is as follows. If the
> first file I read from contains six lines then I expected the resulting
> consolidated file to have the first six lines align with read-from file.
> But they don't. The consolidated file's lines are mixed with the first six
> lines comming from file 1 or file 8 or whatever. The lines read in are not
> contiguous. For example in ch12 the first consolidated line comes from file
> 004 and the second consolidated line comes from 055.
>
> I believe your problem is that you are only reading one line from each
> input file. These two lines:
>
> my $line = readline(READ);
> print WRITE "$line\n";
>
> should be replaced by
>
> my @lines = readline(READ);
> print WRITE @lines;
>
> Note that you do not need to add a newline at the end of each output line,
> as the original newline character[s] will be read in with the lines from
> the input file.
>
>
> >
> > ------------ SCRIPT --------------
> >
> > #!/usr/bin/perl
> >
> > use v5.16.3;
> > # use v5.14.2;
> > use File::Basename;
> > use File::Path;
> >
> > my $base_directory =
> "/home/sherman/perl_documentation/programming_perl_4_examples/programming_perl_examples/program_listings";
> > my $basename_directory = basename($base_directory) || die "Unable to
> determine the basename: $!\n";
> > my $write_directory =
> "/home/sherman/perl_documentation/programming_perl_4_examples/consolidated_perl4_examples";
>
> You should have something like this:
>
> my $homedir =
> '/home/sherman/perl_documentation/programming_perl_4_examples';
>
> and use that for generating the other variables:
>
> my $base_directory = "$homedir/program_listings";
> my $write_directory = "$homedir/consolidated_perl4_examples";
>
> which is easier to write, easier to read, and less error-prone.
>
> > if ( not -e "$write_directory" ) {
> > mkdir("$write_directory") || die "Unable to create $write_directory:
> $!\n";
> > }
>
> You do not have to enclose $write_directory in double-quotes. Doing so can
> cause problems (although probably not here.)
>
> If you leave off the newline at the end of your die message, Perl will
> tell you the line number of the error, which can be very useful sometimes.
>
> >
> > chdir($base_directory) || die "Unable to change directory to
> $basename_directory: $!\n";
> >
> > opendir(PERLDIR, ".") or die "Unable to open $basename_directory: $!\n";
>
> It is generally better to use undefined lexical variables for file handles:
>
> opendir( my $perldir, '.') or die(...);
>
> > my @docdirs = grep { $_ ne '.' and $_ ne '..' } readdir PERLDIR;
> > closedir(PERLDIR) || die "Unable to close $basename_directory:$!\n";
> > foreach my $directory ( @docdirs ) {
> > chdir("$base_directory/$directory") || die "Unable to change
> directory to $directory: $!\n";
> > my $write_file = "$write_directory/$directory";
> > opendir(EXAMPLES, ".") or die "Unable to open $directory: $!\n";
> > my @docfiles = grep {$_ ne '.' and $_ ne '..'} readdir EXAMPLES;
> > closedir(EXAMPLES) || die "Unable to close $directory: $!\n";
> > foreach my $file ( @docfiles ) {
> > my ( $write, $read );
>
> These two variables don't seem to be used anywhere.
>
> > open(WRITE, ">>$write_file") || die "Unable to open $write_file:
> $!\n";
> > open(READ, $file) || die "Unable to open $file: $!\n";
> > my $line = readline(READ) || die "Unable to read $file: $!\n";
> > print WRITE "$line\n";
> > close(WRITE) || die "Unable to close $write_file: $!\n";
> > close(READ) || die "Unable to close $file: $!\n";
> > }
> > }
> >
> > 1;
> >
>
> Good luck!
>
>
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