Reading from Json File garbage after json object - json

Question

I'm using json file in a Perl program. I'm unable to parse the json file.
It is giving following error:
garbage after JSON object, at character offset 2326471 (before "{"response":{"numFou...") at /usr/local/share/perl5/JSON.pm line 171, <$f> line 1.
Here is the code:
print "input json";
open(my $f, "<", "$ARGV[1]");
my $content=<$f>;
my $structured;
eval {
$structured = from_json($content, {utf8 => 1});
};
if ($#) {
$content =~ s/\n/ /g;
my $errMsg = $#;
$errMsg =~ s/\n/ /g;
WriteInfo("Unparseable result for url=$url, error: $errMsg\n") ;
};
How can I fix this error?

Answer 1

How can I fix this error?
You can't fix JSON data automatically. There could be many "fixes" that will get the data through the parser, but it may be difficult to tell which of them is the correct one. You should talk to the source of the data and ask for a correct version
It may be possible to fix the data manually, but you should only attempt this if there is no correct version of the data available. Finding the error in a 2.2MB+ text file by hand isn't a trivial job, and the character position 2326471 is only where the parser found an error, not where the correction should be made
garbage after JSON object ...
This implies that from_json has found the end of the JSON data -- i.e. the final closing brace } or bracket ] -- but there is data in the string after that character. It may be that the file has been written correctly, but there really is spurious data after the end of the JSON. If so then that should be obvious just by examining the data file
Note
Unless you have redefined the $/ variable, these lines
open(my $f, "<", "$ARGV[1]");
my $content = <$f>;
will read just the first line of the file into $content. It may be that the file contains just a single very long line of tex (i.e. it contains no newline characters) but this line in your error handler
$content =~ s/\n/ /g;
implies that ther are newlines in there.
Reading only the first line of a multi-line JSON file wouldn't cause the error that you're seeing, but it is best to read the entire file into memory before decoding it as JSON data, just in case unexpected newlines have crept into the data
Here is a better way of writing your code segment
print "Input JSON\n";
my $content - do {
open my $fh, '<', $ARGV[1] or die qq{Unable to open "$ARGV[1]" for input: $!};
local $/;
<$fh>;
};
my $structured = eval {
from_json( $content, {utf8 => 1} );
};
if ( my $err_msg = $# ) {
$content =~ tr/\n/ /;
$err_msg =~ tr/\n/ /;
WriteInfo("Unparsable result for URL=$url, error: $err_msg\n") ;
};