Using sprintf() to print a Hash

Ruby
1

Hi, I just have a single Hash and want to print it into the standar
output as follows (key: value):

listen_ip: 1.2.3.4
listen_port: 90
use_tls: true
compression: false

2

2011/5/24 Iñaki Baz C. [email protected]:

listen_ip: 1.2.3.4
listen_port: 90
use_tls: true
compression: false

I’m trying to play with sprintf by using %20s and so, with no success.
Any help please?

I’ve got the following output by using sprintf(“%20s %20s”,
“#{key.to_s}:”, value.to_s):

    listen_ip:       1.2.3.4
 listen_port:              90
     use_tls:            true

compression: false

3

2011/5/24 Iñaki Baz C. [email protected]:

but it’s not exactly what I need.
Got it!:

sprintf(" %-20s %20s", “#{key.to_s}:”, value.to_s)

listen_ip: 1.2.3.4
listen_port: 90
use_tls: true
compression: false

4

2011/5/24 Xavier N. [email protected]:

Not sure if I understand correctly, but this seems to do what you are
looking for

hash.each do |key, value|
printf “%-12s %10s\n”, “#{key}:”, value
end

Max field widths may be computed for arbitrary hashes.

Yes, I got exactly that as todl in my previous mail :slight_smile:

– fxn

PD: Note that I use printf, format is the same as sprintf, but you print the
formatted string directly, as in C.

Thanks for pointing it out.

5

Not sure if I understand correctly, but this seems to do what you are
looking for

hash.each do |key, value|
printf “%-12s %10s\n”, “#{key}:”, value
end

Max field widths may be computed for arbitrary hashes.

– fxn

PD: Note that I use printf, format is the same as sprintf, but you print
the
formatted string directly, as in C.

6

On Tue, May 24, 2011 at 7:59 PM, Iaki Baz C. [email protected]
wrote:

… sprintf(" %-20s %20s", “#{key.to_s}:”, value.to_s)

for simple formatting/justification, i just use the just methods since
they are easier (for my brain) to remember.

eg,

h.each do |k,v|
puts k.to_s.ljust(20) + v.to_s.rjust(20)
end

kind regards -botp

7

On Tue, May 24, 2011 at 1:59 PM, Iaki Baz C. [email protected]
wrote:

but it’s not exactly what I need.

Got it!:

sprintf(" %-20s %20s", “#{key.to_s}:”, value.to_s)

That’s overly complicated: you employ two text replacement mechanisms.
Just do

printf(" %-20s: %20s\n", key, value)

Cheers

robert

8

2011/5/24 botp [email protected]:

h.each do |k,v|
puts k.to_s.ljust(20) + v.to_s.rjust(20)
end

Great, I didn’t know about it :slight_smile:

9

2011/5/24 Robert K. [email protected]:

sprintf(" %-20s %20s", “#{key.to_s}:”, value.to_s)

That’s overly complicated: you employ two text replacement mechanisms. Just do

printf(" %-20s: %20s\n", key, value)

Yes, initially I used key.to_s as I have Symbols as keys and thougth
that a string is required.

Changed now. Thanks.

10

On Tue, May 24, 2011 at 5:25 PM, Iñaki Baz C. [email protected]
wrote:

2011/5/24 Robert K. [email protected]:

sprintf(" %-20s %20s", “#{key.to_s}:”, value.to_s)

That’s overly complicated: you employ two text replacement mechanisms.
Just do

printf(" %-20s: %20s\n", key, value)

Yes, initially I used key.to_s as I have Symbols as keys and thougth
that a string is required.

Note that the colon belongs to the argument though. Otherwise they won’t
be
next to their keys.

11

2011/5/24 Xavier N. [email protected]:

Note that the colon belongs to the argument though. Otherwise they won’t be
next to their keys.

True.

12

On Tue, May 24, 2011 at 5:29 PM, Xavier N. [email protected] wrote:

Yes, initially I used key.to_s as I have Symbols as keys and thougth
that a string is required.

Note that the colon belongs to the argument though. Otherwise they won’t be
next to their keys.

Right, I overlooked that. Good catch! I usually prefer to have all
colons aligned, that’s why I probably didn’t notice.

Kind regards

robert