# Question about some octal formatted output?

**URL:** <https://www.ruby-forum.com/t/question-about-some-octal-formatted-output/117208>\
**Category:** Ruby\
**Created:** [October 14, 2007, 8:17pm UTC](https://www.ruby-forum.com/t/question-about-some-octal-formatted-output/117208 "2007-10-14T20:17:49Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![7stud](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/7/57b2e6/32.png) [@7stud](https://www.ruby-forum.com/u/7stud)\
**Post date:** [October 14, 2007, 8:17pm UTC](https://www.ruby-forum.com/t/question-about-some-octal-formatted-output/117208/1 "2007-10-14T20:17:49Z")

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eacute = “”  
eacute \<\< 0xC3 \<\< 0xA9 #eacute\<\< 195 \<\< 169 ; or é

p eacute

–output:—  
“\303\251”

That ouput is in octal–although there is no leading 0.

1. Where does that format come from, i.e. no leading 0?
2. Why is the output in octal and not hex?

I looked up String#\<\< and it says it converts any Fixnum between 0-255  
to a character.

1. Using what character set?

Thanks.

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<div class="post-metadata">

**Author:** ![7stud](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/7/57b2e6/32.png) [@7stud](https://www.ruby-forum.com/u/7stud)\
**Post date:** [October 14, 2007, 10:20pm UTC](https://www.ruby-forum.com/t/question-about-some-octal-formatted-output/117208/2 "2007-10-14T22:20:45Z")

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On Oct 14, 2007, at 11:17 , 7stud – wrote:

> 1. Why is the output in octal and not hex?  
> Its at least as old as C. You’ll probably have to ask some really  
> old timers for the answer.

$ cat octal.c  
#include \<stdio.h\>

void main() { printf("\303\251\n"); }  
$ gcc octal.c  
octal.c: In function ‘main’:  
octal.c:3: warning: return type of ‘main’ is not ‘int’  
$ ./a.out  
é

> I looked up String#\<\< and it says it converts any Fixnum between 0-255  
> to a character.
> 
> 1. Using what character set?

ASCII. Its your terminal that controls how it gets displayed. My  
terminal is set to UTF-8.

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<div class="post-metadata">

**Author:** ![7stud](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/7/57b2e6/32.png) [@7stud](https://www.ruby-forum.com/u/7stud)\
**Post date:** [October 15, 2007, 1:26am UTC](https://www.ruby-forum.com/t/question-about-some-octal-formatted-output/117208/3 "2007-10-15T01:26:42Z")

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7stud – wrote:

> 1. Where does that format come from, i.e. no leading 0?
> 2. Why is the output in octal and not hex?
> 
> I looked up String#\<\< and it says it converts any Fixnum between 0-255  
> to a character.
> 
> 1. Using what character set?

Actually, what’s your problem with all that?

Your ints specified in hex are actually converted to bytes in the  
string. That, interpreted as utf-8, may mean an é.

The conventional syntax for specifying bytes by their integer value in  
string literals, used in C, shells and a number of other environments  
(including Ruby) is a backslash followed by octal digits. (The leading 0  
is used for specifying _integer_ literals in octal.)

String#inspect (which I guess p is using) adopts this syntax for  
displaying non-ascii and/or non-printing bytes in the string.

I really don’t get your third question. There’s no character set  
involved here, beyond how you intended your two bytes to be interpreted.  
Those two bytes remain the same, regardless how they are displayed. They  
may mean two characters in plain old 8-bit charsets, they may mean e.g.  
one é in utf-8, or they may mean what p displays for them.

mortee