On 2017/12/19 10:24 PM, Tony Papadimitriou wrote:
2. Does it understand \n and \t? I put actual line breaks inside
the string >which is OK if run from script file but it won’t work
with one-liners on the >command-line.>
The \n, \t, \r etc. are really dependent on some factors (OS etc.).
Yes, I know all that. The question was if it understands them, not
how they might behave depending on OS.
But that is the entire point.
SQLite doesn't handle or understand \n, \t, \r, \x, \Father
Christmas.... Those things are OS-dependent escapes to get
non-printable characters into command line input. SQlite calls a
Line-Feed a Line-Feed. It is agnostic to how the Line-Feed gets passed
to it. The OS (sometimes) facilitates a conversion of the character
sequence "\" + "n" as a "Line-Feed" when passing it to a command-line
interface, such as sqlite.exe in our case, but by the time sqlite sees
it, it is already a Linefeed character (i.e. ASCII/Unicode/UTF8
Character no. 10) - sqlite doesn't know anything about "\n", it cannot,
does not, and need not interpret it, it is completely irrelevant to
sqlite. "\n" is a function of the OS to allow the user to more easily
send character(10) to a console application, the console application
(thank goodness) need not know anything about "\n". i.e if your SQLite
DOESN'T understand \n, it is a shortcoming/by design/feature of your OS,
it has nothing to do with SQLite.
Is that more clear?
The same goes for UTF8.
SQLite isn't so much "ABLE" to read UTF8, as it is indeed the only way
it communicates, it doesn't do non-UTF8. UTF8 is the only language it
speaks. So if your UTF8 doesn't get passed correctly to SQLite it is
typically a problem of the OS Code page or the sqlite-using application
running in the console. (Btw. sqlite3.exe and its ilk are all command
line applications and isn't the sqlite engine itself, your fixes wrt the
UTF8 probably fixed the CLI in some way and it may well be a bug there,
so if you can submit a test case it would be helpful - please give all
the details).
So, is there any way to advance to next line from a command line
printf()?
Extremely easily:
SELECT Char(10);
- or -
SELECT printf( '%s', Char(10) );
And before you ask....
Char(07) = BELL
Char(08) = BACKSPACE
Char(09) = TAB = \t
Char(10) = LF = \n
Char(11) = VTAB (Vertical Tab)
Char(12) = FF (FormFeed) - in case you print to an old-style line
printer (LPT1)
Char(13) = CR = \r (Carriage Return)
Char(27) = ESC
Char(32) = SPACE
That more or less covers the important non-printables / invisible
characters.
Hope that helps :)
Ryan
Ryan
Thanks
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