Re: Detecting line terminators in a CSV file
- From: krahnj@xxxxxxxxx (John W. Krahn)
- Date: Thu, 29 Jun 2006 21:04:25 -0700
Daniel Kasak wrote:
Greetings.
Hello,
I'm trying to write a CSV import routine for MySQL ( possibly will
extend it with a flashy GUI and release open-source ).
I'm having great difficulty doing this under Windows. If I use the code
below under Linux, it works perfectly, detecting correctly whether the
file has a Windows ( \r\n ) EOL sequence or a Unix ( \n ) EOL sequence.
However when I run it under Windows, the 1st substr() function that gets
the last 2 characters doesn't see things properly! Instead, it sees the
\n character and then a double quote ( " ) ... all the fields are
wrapped in double-quotes.
Why doesn't this code see the \r portion under Windows?
Because when on Windows the CR LF pair is converted to the "\n" newline character.
perldoc PerlIO
[snip]
:crlf
A layer that implements DOS/Windows like CRLF line endings. On
read converts pairs of CR,LF to a single "\n" newline character.
On write converts each "\n" to a CR,LF pair. Note that this layer
likes to be one of its kind: it silently ignores attempts to be
pushed into the layer stack more than once.
Also see the "Newlines" section of perlport:
perldoc perlport
How should I be doing the stuff below so that it works?
Are you sure that you want to "fix" this?
perldoc -f binmode
# Parse the 1st line of the import file and extract fieldnames
eval{
open SOURCE, $options->{source}
|| die "Failed to open file $options->{source}.\nIs the file
already open?";
};
if ( $@ ) {
Gtk2::Ex::Dialogs::ErrorMsg->new_and_run(
title => "Error opening file!",
text => $@
);
return FALSE;
}
You don't *have* to die if open doesn't work! And besides, using the high
precedence || operator means it won't die even if you wanted it to.
open SOURCE, '<', $options->{source} or do {
Gtk2::Ex::Dialogs::ErrorMsg->new_and_run(
title => 'Error opening file!',
text => $!
);
return FALSE;
};
# Read the 1st line
my $fieldnames = <SOURCE>;
# Close file
close SOURCE;
# Figure out what happens at the end of each line
# This should either be \n ( Unix ), or \r\n ( Windows )
my $line_terminator;
if ( substr( $fieldnames, length( $fieldnames ) -2, 2 ) eq "\r\n" ) {
You don't have to call the length() function, you can just use a negative number:
if ( substr( $fieldnames, -2, 2 ) eq "\r\n" ) {
John
--
use Perl;
program
fulfillment
.
- Follow-Ups:
- Re: Detecting line terminators in a CSV file
- From: Daniel Kasak
- Re: Detecting line terminators in a CSV file
- References:
- Detecting line terminators in a CSV file
- From: Daniel Kasak
- Detecting line terminators in a CSV file
- Prev by Date: Detecting line terminators in a CSV file
- Next by Date: Re: Detecting line terminators in a CSV file
- Previous by thread: Detecting line terminators in a CSV file
- Next by thread: Re: Detecting line terminators in a CSV file
- Index(es):
Relevant Pages
|
