Hi All,
I've googled for hours and banged my head, but no luck. What am I doing
wrong?
I'm trying to pull a PDF blob out of MySQL on Linux:
Step 1 - Check the PDF file before putting it in the database.
/*Before Size*/
# ls -l /tmp/orig.pdf
-rw------- 1 daemon daemon 14288 Mar 3 09:38 /tmp/orig.pdf
/*Before Checksum*/
#md5sum /tmp/orig.pdf
614aff27a25182fa4c5d6b6740e34836 /tmp/orig.pdf
/* Sanity checks*/
#head -1 /tmp/orig.pdf
%PDF-1.2
#pdf2ps /tmp/orig.pdf /tmp/orig.ps
/* No errors are returned so the PDF file looks okay.*/
Step 2 - Put the PDF into MySQL as a BLOB
/usr/bin/mysql -h SQLSERVERHOST -u dbuser -p dbpass database
UPDATE mytable set myblobcolumn=LOAD_FILE("/tmp/orig.pdf") where
mykey="1";
/* I know the PDF is okay because I can now read it and display it with a
Python CGI using a web browser. */
Step 3 - Read it with PERL DBI
#!/usr/bin/perl -w
use DBI;
use strict;
my $user = "user";
my $password = "password";
my $dsn = "dbi:mysql:database";
my $dbh = DBI->connect($dsn, $user, $password) || die "Cannot open db";
my $sql = "SELECT * from mytable where mykey = '1'";
my $sth = $dbh->prepare($sql, { 'LongReadLen' => 1638400 });
my $numrows = $sth->execute;
open OUTPUT, ">/tmp/extracted.pdf";
my $ref = $sth->fetchrow_hashref;
my $newdata = $$ref{'myblobcolumn'};
print OUTPUT $newdata;
close OUTPUT;
$sth->finish;
$dbh->disconnect;
/* I used a very long and very arbitrary read length. This program runs
without errors. */
Step 4 - Try to use the PDF file I just extracted.
#ls -l /tmp/extracted.pdf
-rw-r--r-- 1 root root 19893 Mar 3 09:53 /tmp/extracted.pdf
/* It is bigger! */
# md5sum /tmp/extracted.pdf
8c145ae11c464bce0ac88cf775828d13 /tmp/extracted.pdf
/* Its checksum changed*/
# head -1 /tmp/extracted.pdf
%PDF-1.2
/* Still 'might' be useable PDF?? */
# pdf2ps /tmp/extracted.pdf
Error: /syntaxerror in readxref
Operand stack:
Execution stack:
%interp_exit
runexec2 --nostringval-- --nostringval-- --nostringval-- 2
%stopped_push --nostringval-- --nostringval-- --nostringval-- false
1 %stopped_push 1 3 %oparray_pop 1 3
%oparray_pop --nostringval-- --nostringval-- --nostringval-- --nostr
ingval-- --nostringval-- --nostringval--
Dictionary stack:
--dict:1051/1123(ro)(G)-- --dict:0/20(G)-- --dict:92/200(L)-- --dic
t:92/200(L)-- --dict:97/127(ro)(G)-- --dict:229/230(ro)(G)-- --dict:14
/15(L)--
Current allocation mode is local
GNU Ghostscript 7.05: Unrecoverable error, exit code 1
/* Nope. It is not valid PDF code anymore */
Where did I go wrong?
--Karl
