# Purpose:
#    Simple search with Perl for a pattern in some file.
#
#    The advantages compared to thinkable auxiliary constructs using the
#    mysqltest language and SQL are:
#    1. We do not need a running MySQL server.
#    2. SQL causes "noise" during debugging and increases the size of logs.
#       Perl code does not disturb at all.
#
#    The environment variables SEARCH_FILE and SEARCH_PATTERN must be set
#    before sourcing this routine.
#
#    Optionally, SEARCH_RANGE can be set to the max number of bytes of the file
#    to search. If negative, it will search that many bytes at the end of the
#    file. The default is to search only the first 50000 bytes of the file.
#
#    In case of
#    - SEARCH_FILE and/or SEARCH_PATTERN is not set
#    - SEARCH_FILE cannot be opened
#    - SEARCH_FILE does not contain SEARCH_PATTERN
#    the test will abort immediate.
#    MTR will report something like
#    ....
#    worker[1] Using MTR_BUILD_THREAD 300, with reserved ports 13000..13009
#    main.1st                                 [ pass ]      3
#    innodb.innodb_page_size                  [ fail ]
#            Test ended at 2011-11-11 18:15:58
#
#    CURRENT_TEST: innodb.innodb_page_size
#    # ERROR: The file '<name>' does not contain the expected pattern  <pattern>
#    mysqltest: In included file "./include/search_pattern_in_file.inc":
#    included from ./include/search_pattern_in_file.inc at line 36:
#    At line 25: command "perl" failed with error 255. my_errno=175
#
#    The result from queries just before the failure was:
#    ...
#    - saving '<some path>' to '<some path>'
#    main.1st                                 [ pass ]      2
#
# Typical use case (check invalid server startup options):
#    let $error_log= $MYSQLTEST_VARDIR/log/my_restart.err;
#    --error 0,1
#    --remove_file $error_log
#    let SEARCH_FILE= $error_log;
#    let SEARCH_RANGE= -50000;
#    # Stop the server
#    let $restart_file= $MYSQLTEST_VARDIR/tmp/mysqld.1.expect;
#    --exec echo "wait" > $restart_file
#    --shutdown_server 10
#    --source include/wait_until_disconnected.inc
#
#    --error 1
#    --exec $MYSQLD_CMD <whatever wrong setting> > $error_log 2>&1
#    # The server restart aborts
#    let SEARCH_PATTERN= \[ERROR\] Aborting;
#    --source include/search_pattern_in_file.inc
#
# Created: 2011-11-11 mleich
#

perl;
    use strict;
    die "SEARCH_FILE not set" unless $ENV{'SEARCH_FILE'};
    my @search_files= glob($ENV{'SEARCH_FILE'});
    my $search_pattern= $ENV{'SEARCH_PATTERN'} or die "SEARCH_PATTERN not set";
    my $search_range=   $ENV{'SEARCH_RANGE'};
    my $content;
    $search_range= 50000 unless $search_range =~ /-?[0-9]+/;
    foreach my $search_file (@search_files) {
        open(FILE, '<', $search_file) or die("Unable to open '$search_file': $!\n");
        my $file_content;
        if ($search_range >= 0) {
           read(FILE, $file_content, $search_range, 0);
        } else {
           my $size= -s $search_file;
           $search_range = -$size if $size > -$search_range;
           seek(FILE, $search_range, 2);
           read(FILE, $file_content, -$search_range, 0);
        }
        close(FILE);
        $content.= $file_content;
    }
    $ENV{'SEARCH_FILE'} =~ s{^.*?([^/\\]+)$}{$1};
    if ($content =~ m{$search_pattern}) {
      die "FOUND /$search_pattern/ in $ENV{'SEARCH_FILE'}\n"
      if $ENV{SEARCH_ABORT} eq 'FOUND';
      print "FOUND /$search_pattern/ in $ENV{'SEARCH_FILE'}\n"
      unless defined $ENV{SEARCH_ABORT};
    } else {
      die "NOT FOUND /$search_pattern/ in $ENV{'SEARCH_FILE'}\n"
      if $ENV{SEARCH_ABORT} eq 'NOT FOUND';
      print "NOT FOUND /$search_pattern/ in $ENV{'SEARCH_FILE'}\n"
      unless defined $ENV{SEARCH_ABORT};
    }
EOF
