How can i get the first letter of this string

[duc nguyen]

Hello, i'm a newbie. I have a question that how can i get the first
letter of this string: "=C3=A1 is the first letter".
my solution:

string =3D "=C3=A1 is the first letter"
str =3D string[0..1] # [0..1] because =C3=A1 =3D 2byte

But in many case i don't know the size of the first letter.
Any help would be much appreciated.

-- =

Posted via http://www.ruby-forum.com/.=

 

[7stud --]

You can use the /u flag for a regex to signal utf-8 matching...but you
didn't mention what encoding your strings are in. The regex would look
like this:

"some string" =~ /^(.)/u
puts $1

You also didn't mention what version of ruby you are using...ruby 1.8 or
1.9.

 

[Thiago Massa]

[Note: parts of this message were removed to make it a legal post.]

irb(main):023:0> bacon="chunky"
=> "chunky"
irb(main):024:0> bacon[0]
=> 99
irb(main):025:0> bacon[0].chr
=> "c"

99 is the ascii number that represents the letter 'c'.

I think that explains what you want.

 

[Michael Edgar]

That won't work on Ruby 1.9, as bacon[0] will return the first actual =
character. This technique
works on both:

bacon =3D "chunky" =3D> "chunky"
bacon[0,1]

=3D> "c"

Michael Edgar
(e-mail address removed)
http://carboni.ca/

irb(main):023:0> bacon=3D"chunky"
=3D> "chunky"
irb(main):024:0> bacon[0]
=3D> 99
irb(main):025:0> bacon[0].chr
=3D> "c"
=20
99 is the ascii number that represents the letter 'c'.
=20
I think that explains what you want.
=20
--=20
Thiago Fernandes Massa
11 83979414

 

[duc nguyen]

thanks for your help!
My strings are in UTF-8 encoding. Ruby version 1.8.7

I just follow your instructions and got the first letter of that string. =

But i still not get the remainder of string after get the first letter.

My problem now is convert the UTF-8 string to ansi string.
ex: purpose: change "=C3=A2=C3=AA=C6=A1=C3=AD=C5=A9" to "aeoiu".
I really confuse and don't have any way to do that.

Regards,

-- =

Posted via http://www.ruby-forum.com/.=

 

[pp]

DQpISSwgdGhlcmUgbWlnaHQgYmUgbm8gZWFzeSB3YXkgdG8gd29yayB0aGlzIGFyb3VuZC50YWtl
IGEgbG9vayBhdCBBU0NJSSB0YWJsZSBhbmQgdW5pY29kZSB0YWJsZSwgdHJ5IHRvIHdyaXRlIGEg
bWFwIGZ1bmN0aW9uIHlvdXJzZWxmDQoNCj4gRGF0ZTogVGh1LCAzIE1hciAyMDExIDE2OjMyOjA2
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YW4gaSBnZXQgdGhlIGZpcnN0IGxldHRlciBvZiB0aGlzIHN0cmluZw0KPiBUbzogcnVieS10YWxr
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dCBzdHJpbmcuIA0KPiBCdXQgaSBzdGlsbCBub3QgZ2V0IHRoZSByZW1haW5kZXIgb2Ygc3RyaW5n
IGFmdGVyIGdldCB0aGUgZmlyc3QgbGV0dGVyLg0KPiANCj4gTXkgcHJvYmxlbSBub3cgaXMgY29u
dmVydCB0aGUgVVRGLTggc3RyaW5nIHRvIGFuc2kgc3RyaW5nLg0KPiBleDogcHVycG9zZTogY2hh
bmdlICLDosOqxqHDrcWpIiB0byAiYWVvaXUiLg0KPiBJIHJlYWxseSBjb25mdXNlIGFuZCBkb24n
dCBoYXZlIGFueSB3YXkgdG8gZG8gdGhhdC4NCj4gDQo+IFJlZ2FyZHMsDQo+IA0KPiAtLSANCj4g
UG9zdGVkIHZpYSBodHRwOi8vd3d3LnJ1YnktZm9ydW0uY29tLy4NCiAJCSAJICAgCQkgIA==

 

[Adam Prescott]

irb(main):023:0> bacon=3D"chunky"
=3D> "chunky"
irb(main):024:0> bacon[0]
=3D> 99
irb(main):025:0> bacon[0].chr
=3D> "c"

99 is the ascii number that represents the letter 'c'.

I think that explains what you want.

That won't work on Ruby 1.9, as bacon[0] will return the first actual
character. This technique
works on both:

bacon =3D "chunky" =3D> "chunky"
bacon[0,1]

=3D> "c"

This will not work on Ruby 1.8, because the character involved is a two-byt=
e
character, and before 1.9 there's nothing but bytes.

s =3D "=C3=A1"
s.inspect #=3D> =3D> "\303\241"
s[0] #=3D> "\303"
s[0, 1] #=3D> "\303"
s[0].chr #=3D> "\303"

Since you're on 1.8.7, you could use

$KCODE =3D "U" # UTF-8
s.chars.first #=3D> "=C3=A1"

Note that if you do not set $KCODE, you will just get "\303".

 

[7stud --]

duc nguyen wrote in post #985120:

 

[duc nguyen]

thanks for all!
I tried all instructions above and they work fine when i run from =

command line. But when i insert them to my .rb file in my project and =

debug, An error has happen, and i don't know why

"=C3=A1 is the first letter" =3D~ /^(.)(.*)/u
puts "-->#{$1}<--"
puts "-->#{$2}<--"

--output in command prompt window:--
-->=C3=A1<--
--> is the first letter<--

But in the log file of my project
I 03/04/2011 09:07:39:169 b0353000 APP| -->=E2=88=9A<--
I 03/04/2011 09:07:39:169 b0353000 APP| -->=C2=B0 is the first letter<--=


Again, i change the code:

"=C3=A1 is the first letter" =3D~ /^(..)(.*)/u
puts "-->#{$1}<--"
puts "-->#{$2}<--"

And now it works.
I 03/04/2011 09:11:03:414 b03d5000 APP| -->=C3=A1<--
I 03/04/2011 09:11:03:414 b03d5000 APP| --> is the first letter<--

My project is a rhodes project. Rhodes version 2.2.6. Ruby 1.8.7.

-- =

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[7stud --]

Wow...that's strange: when I run my example, no log file is created. I
wonder why that is???

In other words, you are running some extra code that writes to a file,
and you want us to troubleshoot that code without seeing it? O...kay.
Your statement that writes to the file takes one byte of the two bytes
making up the and writes the single byte to the file, which is then
interpreted as gibberish by whatever application you are using to view
the file.