一款 userscript, 令您只要雙擊選取 ptt
上 IP 便可即時取得相關資訊.
適用於 www.ptt.cc, term.ptt.cc.
一款 userscript, 令您只要雙擊選取 ptt
上 IP 便可即時取得相關資訊.
適用於 www.ptt.cc, term.ptt.cc.
if _, err := os.Stat("/path/to/whatever"); os.IsNotExist(err) { | |
// path/to/whatever does not exist | |
} | |
if _, err := os.Stat("/path/to/whatever"); !os.IsNotExist(err) { | |
// path/to/whatever exists | |
} |
Magic words:
psql -U postgres
Some interesting flags (to see all, use -h
or --help
depending on your psql version):
-E
: will describe the underlaying queries of the \
commands (cool for learning!)-l
: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)