Scriptlets
Petits bouts de code à usage divers.
watchline.pl - Permet de surveiller les changements d'une ligne dans un fichier
#!/usr/bin/perl
unless( $ARGV[1] ) {
print "Usage : $O <fichier> <pattern> [intervalle]\nIntervalle par défaut = 1s.\n";
exit;
}
my $interval = $ARGV[2]?$ARGV[2]:1;
my $l = "";
while(1) {
open my $fd, "< $ARGV[0]";
while(<$fd>) { last if /$ARGV[1]/; }
chomp;
if( $_ ne $l ) {
my $t = `date +[%H:%M:%S]`;
chomp $t;
print "$t ", $l = $_, "\n";
}
close $fd;
sleep $interval;
}
mks - Crée un fichier exécutable et y place le shebang en fonction de l'extension
#!/bin/sh
if [ $# -ne 1 ]; then
echo "Usage : mks <nom du script>" && exit 1
fi
if [ -e "$1" ]; then
echo "$1 existe déjà." && exit 1
fi
> "$1"
chmod +x "$1"
if [ "${1: -3}" == ".pl" ]; then
echo -e "#!/usr/bin/perl\n\n" > "$1"
fi
if [ "${1: -3}" == ".sh" ]; then
echo -e "#!/bin/sh\n\n" > "$1"
fi
$EDITOR "$1"
man - CGI pour afficher une page man avec liens
#!/usr/bin/perl
$s = "";
$p = "man";
#print $ENV{QUERY_STRING};
($p) = $ENV{QUERY_STRING} =~ m!p=([a-z._]+)!;
($s) = $ENV{QUERY_STRING} =~ m!s=(.)!;
open $fd, "man $s $p 2>&1 |";
@l = <$fd>;
$l = join "", @l;
$l =~ s!(.)\010\1!<b>\1</b>!sg;
$l =~ s!_\010(.)!<u>\1</u>!sg;
$l =~ s!</(.+)><\1>!!sg;
$l =~ s!(</.>)?([a-z._]+)(</.>)?\((.)\)!< a href=man?p=\2&s=\4>\1\2\3\(\4\)</a>!sg;
print <<END;
Content-type: text/html\n
<html>
<head><title>$p($s)</title></head>
<body><form><input type=text name=p><input type=submit value=man></form>
<pre>$l</pre></body></html>
END
iptables chains diagram
Network
-----------+-----------
|
+-------+------+
| mangle |
| PREROUTING | <- MARK REWRITE
+-------+------+
|
+-------+------+ Policy rule database
| PRDB | <- controlled by ip rule
+-------+------+
|
+-------+------+
| nat |
| PREROUTING | <- DEST REWRITE
+-------+------+
|
packet is for +-------+------+ packet is for
this address | INPUT | another address
+--------------+ ROUTING +---------------+
| +--------------+ |
+-------+------+ |
| filter | |
| INPUT | |
+-------+------+ |
| |
+-------+------+ |
| Local | |
| Process | |
+-------+------+ |
| |
+-------+------+ |
| OUTPUT | +-------+-------+
| ROUTING | | filter |
+-------+------+ | FORWARD |
| +-------+-------+
+-------+------+ |
| mangle | |
| OUTPUT | MARK REWRITE |
+-------+------+ |
| |
+-------+------+ |
| nat | |
| OUTPUT | DEST REWRITE |
+-------+------+ |
| |
+-------+------+ |
| filter | |
| OUTPUT | |
+-------+------+ |
| |
| |
+----------------+ +--------------------+
| |
| |
+--+-------+---+ selection of the output
| | interface,
| FORWARDING | selection of the next hop,
+-------+------+ encapsulation, etc.
|
|
+-------+------+
| nat |
| POSTROUTING | SOURCE REWRITE
+-------+------+
|
|
+-------+------+
| TRAFFIC |
| QUEUE | <- controlled by tc
+-------+------+
|
|
-----------+-----------
Network
