Static Scoping 從 Definition 找 Scope const int b = 5;
int foo()
{
int a = b + 5;
return a;
}
int bar()
{
int b = 2;
return foo();
}
int main()
{
foo(); // returns 10
bar(); // returns 10
return 0;
}
|
Dynamic scoping 從 Call Stack 找 Scope const int b = 5;
int foo()
{
int a = b + 5;
return a;
}
int bar()
{
int b = 2;
return foo();
}
int main()
{
foo(); // returns 10
bar(); // returns 7
return 0;
}
|
|---|
# # Regular cron jobs for the cron-apt package # # Every night at 4 o'clock. 0 4 * * * root test -x /usr/sbin/cron-apt && /usr/sbin/cron-apt # Every hour. # 0 * * * * root test -x /usr/sbin/cron-apt && /usr/sbin/cron-apt /etc/cron-apt/config2 # Every five minutes. # */5 * * * * root test -x /usr/sbin/cron-apt && /usr/sbin/cron-apt /etc/cron-apt/config2
/etc/cron-apt/action.d$ ls 0-update 3-download /etc/cron-apt/action.d$ cat 0-update update -o quiet=2 /etc/cron-apt/action.d$ cat 3-download autoclean -y dist-upgrade -d -y -o APT::Get::Show-Upgraded=true
CRON-APT RUN [/etc/cron-apt/config]: Tue Jun 25 04:00:01 BST 2013 CRON-APT SLEEP: 2274, Tue Jun 25 04:37:55 BST 2013 CRON-APT ACTION: 0-update CRON-APT LINE: /usr/bin/apt-get -o quiet=1 update -o quiet=2 CRON-APT ACTION: 3-download CRON-APT LINE: /usr/bin/apt-get -o quiet=1 autoclean -y Reading package lists... Building dependency tree... Reading state information... CRON-APT LINE: /usr/bin/apt-get -o quiet=1 dist-upgrade -d -y -o APT::Get::Show-Upgraded=true Reading package lists... Building dependency tree... Reading state information... The following NEW packages will be installed: ruby-rgen The following packages will be upgraded: cpan-libnet-http-perl facter libpython2.7 libvirt0 nodejs puppet puppet-common puppetmaster puppetmaster-common python python-dev python-django python-minimal python2.7 python2.7-dev python2.7-minimal uwsgi-core uwsgi-plugin-carbon uwsgi-plugin-cgi uwsgi-plugin-corerouter uwsgi-plugin-http uwsgi-plugin-psgi uwsgi-plugin-python uwsgi-plugin-rack-ruby1.8 uwsgi-plugin-rack-ruby1.9.1 25 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. Need to get 0 B/49.3 MB of archives. After this operation, 5977 kB of additional disk space will be used. Download complete and in download only mode
$ pip install pycrypto==2.6 $ dpkg -l | grep python-crypto ii python-crypto 2.4.1-1ubuntu0.1 cryptographic algorithms and protocols for Python $ pip freeze | grep pycrypto pycrypto==2.6
#!/usr/bin/perl
use strict;
use warnings;
my $directory = '/tmp';
opendir (DIR, $directory) or die $!;
while (my $file = readdir(DIR)) {
print "$file\n";
}
closedir(DIR);
@filelist = glob "/usr/lib/perl/*.pl";
use File::Find;
find(\&wanted, @directories_to_search);
sub wanted { ... }
my $rule = File::Find::Rule->new;
$rule->file;
$rule->maxdepth(1);
$rule->name("*.pl");
$rule->exec( sub { -M $_ > 3});
my @fid_files = sort { $a cmp $b } $rule->in($curr_path);
# find the files modified in 30 days. $ find . -iname "*.c" -mtime -30 -type f # find the files modified over 30 days. $ find . -iname "*.c" -mtime +30 -type f # find the files modified between 20-30 days ago. $ find . -mtime -30 -mtime +20 -type f # find the files modified in 30 days, but the based time is 00:00:00 today, not current time. $ find . -daystart -mtime 0 -type f # find the files modified between 2012-01-01 and 2013-01-01 $ touch --date "2012-01-01" /tmp/start $ touch --date "2013-01-01" /tmp/end $ find . -type f -newer /tmp/start -not -newer /tmp/end
# list all tasks that is not in running state $ ps -eN r # list all tasks that is in running state $ ps -e r
$ top -b -n 1 | awk '{if (NR <=7) print; else if ($8 == "D") {print; count++} } END {print "Total status D: "count}'
top - 03:06:19 up 12 days, 22:30, 2 users, load average: 0.00, 0.04, 0.05
Tasks: 120 total, 1 running, 118 sleeping, 1 stopped, 0 zombie
Cpu(s): 0.2%us, 0.4%sy, 0.0%ni, 99.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 1985624k total, 1682512k used, 303112k free, 211976k buffers
Swap: 407548k total, 2836k used, 404712k free, 708468k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
Total status D:
>>> import twill.shell >>> twill.shell.main() -= Welcome to twill! =- current page: *empty page* >> help Undocumented commands: ====================== add_auth fa info save_html title add_extra_header find load_cookies setglobal url agent follow notfind setlocal back formaction redirect_error show clear_cookies formclear redirect_output show_cookies clear_extra_headers formfile reload show_extra_headers code formvalue reset_browser showforms config fv reset_error showhistory debug get_browser reset_output showlinks echo getinput run sleep exit getpassword runfile submit extend_with go save_cookies tidy_ok >> go https://login.yahoo.com/config/login ==> at https://login.yahoo.com/config/login current page: https://login.yahoo.com/config/login >> showforms Form name=login_form (#2) ## ## __Name__________________ __Type___ __ID________ __Value__________________ 29 login text username 30 passwd password passwd 31 .persistent checkbox persistent [] of ['y'] 32 1 .save submi ... .save >> setlocal login pjack1981 current page: https://login.yahoo.com/config/login >> setlocal passwd xxxxxxxx current page: https://login.yahoo.com/config/login >> formvalue 2 login $login current page: https://login.yahoo.com/config/login >> formvalue 2 passwd $passwd current page: https://login.yahoo.com/config/login >> showforms Form name=login_form (#2) ## ## __Name__________________ __Type___ __ID________ __Value__________________ 29 login text username pjack1981 30 passwd password passwd xxxxxxxx 31 .persistent checkbox persistent [] of ['y'] 32 1 .save submi ... .save >> submit Note: submit is using submit button: name=".save", value="" Following HTTP-EQUIV=REFRESH to http://my.yahoo.com current page: http://my.yahoo.com >> code 200 current page: http://my.yahoo.com >> code 20 ERROR: code is 200 != 20 current page: http://my.yahoo.com
$ cat test.twill setlocal login pjack1981 setlocal passwd xxxxxxxx go https://login.yahoo.com/config/login formvalue 2 login $login formvalue 2 passwd $passwd submit code 200 $ twill-sh test.twill >> EXECUTING FILE test.twill AT LINE: test.twill:1 AT LINE: test.twill:2 AT LINE: test.twill:4 ==> at https://login.yahoo.com/config/login AT LINE: test.twill:5 AT LINE: test.twill:6 AT LINE: test.twill:7 Note: submit is using submit button: name=".save", value="" Following HTTP-EQUIV=REFRESH to http://my.yahoo.com AT LINE: test.twill:9 -- 1 of 1 files SUCCEEDED.
