[Pharo-project] Printing hexadecimal values of a string
Hello all, I get a strange behaviour while trying to print hexadecimal values of a string. Context: I get a SHA1 hash from a binary stream, store it into a string, and I want to display that string (using asHex). Problem: for values inferior to 16, the leading zero is ignored. (15 -> 'F' instead of '0F'). I could modify SmallInteger>>printStringBase: to always include the leading zero, but I fear I'm going to break a lot of code doing that. Is there a better way to fix my problem? apart from using directly the following: aStream do:[:val | val printStringBase:16 nDigits:2] Best regards, Geoffroy
Hi Geoffroy, On 19 Dec 2010, at 21:55, Geoffroy Couprie wrote:
Hello all,
I get a strange behaviour while trying to print hexadecimal values of a string.
Context: I get a SHA1 hash from a binary stream, store it into a string, and I want to display that string (using asHex).
Problem: for values inferior to 16, the leading zero is ignored. (15 -> 'F' instead of '0F').
I could modify SmallInteger>>printStringBase: to always include the leading zero, but I fear I'm going to break a lot of code doing that. Is there a better way to fix my problem? apart from using directly the following: aStream do:[:val | val printStringBase:16 nDigits:2]
Best regards,
Geoffroy
Why would you not use the ByteArray>>#hex method ? #(0 1 2 253 254 255) asByteArray hex '000102fdfeff' Sven
I know how your feel. My code: hexHashFrom: aByteString "#hex will omit a leading 0. If that's the case insert leading 0." ^aByteString asByteArray hex asLowercase forceTo: 40 paddingStartWith: $0 Max On 19.12.2010, at 22:54, Sven Van Caekenberghe wrote:
Hi Geoffroy,
On 19 Dec 2010, at 21:55, Geoffroy Couprie wrote:
Hello all,
I get a strange behaviour while trying to print hexadecimal values of a string.
Context: I get a SHA1 hash from a binary stream, store it into a string, and I want to display that string (using asHex).
Problem: for values inferior to 16, the leading zero is ignored. (15 -> 'F' instead of '0F').
I could modify SmallInteger>>printStringBase: to always include the leading zero, but I fear I'm going to break a lot of code doing that. Is there a better way to fix my problem? apart from using directly the following: aStream do:[:val | val printStringBase:16 nDigits:2]
Best regards,
Geoffroy
Why would you not use the ByteArray>>#hex method ?
#(0 1 2 253 254 255) asByteArray hex
'000102fdfeff'
Sven
max on which class do you define it? do you have some tests? Stef On Dec 19, 2010, at 11:40 PM, Max Leske wrote:
I know how your feel. My code:
hexHashFrom: aByteString "#hex will omit a leading 0. If that's the case insert leading 0." ^aByteString asByteArray hex asLowercase forceTo: 40 paddingStartWith: $0
Max
On 19.12.2010, at 22:54, Sven Van Caekenberghe wrote:
Hi Geoffroy,
On 19 Dec 2010, at 21:55, Geoffroy Couprie wrote:
Hello all,
I get a strange behaviour while trying to print hexadecimal values of a string.
Context: I get a SHA1 hash from a binary stream, store it into a string, and I want to display that string (using asHex).
Problem: for values inferior to 16, the leading zero is ignored. (15 -> 'F' instead of '0F').
I could modify SmallInteger>>printStringBase: to always include the leading zero, but I fear I'm going to break a lot of code doing that. Is there a better way to fix my problem? apart from using directly the following: aStream do:[:val | val printStringBase:16 nDigits:2]
Best regards,
Geoffroy
Why would you not use the ByteArray>>#hex method ?
#(0 1 2 253 254 255) asByteArray hex
'000102fdfeff'
Sven
Hi Stef Sorry, I should have been more specific. This is a method I use in my own application. I'm not sure if I did test the method but I could have a look if you like. Max On 20.12.2010, at 09:11, Stéphane Ducasse wrote:
max on which class do you define it?
do you have some tests?
Stef
On Dec 19, 2010, at 11:40 PM, Max Leske wrote:
I know how your feel. My code:
hexHashFrom: aByteString "#hex will omit a leading 0. If that's the case insert leading 0." ^aByteString asByteArray hex asLowercase forceTo: 40 paddingStartWith: $0
Max
On 19.12.2010, at 22:54, Sven Van Caekenberghe wrote:
Hi Geoffroy,
On 19 Dec 2010, at 21:55, Geoffroy Couprie wrote:
Hello all,
I get a strange behaviour while trying to print hexadecimal values of a string.
Context: I get a SHA1 hash from a binary stream, store it into a string, and I want to display that string (using asHex).
Problem: for values inferior to 16, the leading zero is ignored. (15 -> 'F' instead of '0F').
I could modify SmallInteger>>printStringBase: to always include the leading zero, but I fear I'm going to break a lot of code doing that. Is there a better way to fix my problem? apart from using directly the following: aStream do:[:val | val printStringBase:16 nDigits:2]
Best regards,
Geoffroy
Why would you not use the ByteArray>>#hex method ?
#(0 1 2 253 254 255) asByteArray hex
'000102fdfeff'
Sven
On Dec 19, 2010, at 9:55 PM, Geoffroy Couprie wrote:
Hello all,
I get a strange behaviour while trying to print hexadecimal values of a string.
Context: I get a SHA1 hash from a binary stream, store it into a string, and I want to display that string (using asHex).
Problem: for values inferior to 16, the leading zero is ignored. (15 -> 'F' instead of '0F').
indeed printStringHex prints F instead of 0F 15 printStringHex 'F' 15 hex '16rF' Geoffroy could you add a variant that produces the correct behavior with some tests?
I could modify SmallInteger>>printStringBase: to always include the leading zero, but I fear I'm going to break a lot of code doing that. Is there a better way to fix my problem? apart from using directly the following: aStream do:[:val | val printStringBase:16 nDigits:2]
Best regards,
Geoffroy
On Mon, 20 Dec 2010, Stéphane Ducasse wrote:
On Dec 19, 2010, at 9:55 PM, Geoffroy Couprie wrote:
Hello all,
I get a strange behaviour while trying to print hexadecimal values of a string.
Context: I get a SHA1 hash from a binary stream, store it into a string, and I want to display that string (using asHex).
Problem: for values inferior to 16, the leading zero is ignored. (15 -> 'F' instead of '0F').
indeed printStringHex prints F instead of 0F 15 printStringHex 'F' 15 hex '16rF'
Geoffroy could you add a variant that produces the correct behavior with some tests?
No need to do that. As Sven pointed out, he can simply use ByteArray >> #hex. Since his stream is already binary, he can also avoid converting his data to a string. Levente
I could modify SmallInteger>>printStringBase: to always include the leading zero, but I fear I'm going to break a lot of code doing that. Is there a better way to fix my problem? apart from using directly the following: aStream do:[:val | val printStringBase:16 nDigits:2]
Best regards,
Geoffroy
Hello, 2010/12/20 Levente Uzonyi <leves@elte.hu>:
On Mon, 20 Dec 2010, Stéphane Ducasse wrote:
On Dec 19, 2010, at 9:55 PM, Geoffroy Couprie wrote:
Hello all,
I get a strange behaviour while trying to print hexadecimal values of a string.
Context: I get a SHA1 hash from a binary stream, store it into a string, and I want to display that string (using asHex).
Problem: for values inferior to 16, the leading zero is ignored. (15 -> 'F' instead of '0F').
indeed printStringHex prints F instead of 0F 15 printStringHex     'F' 15 hex     '16rF'
Geoffroy could you add a variant that produces the correct behavior with some tests?
No need to do that. As Sven pointed out, he can simply use ByteArray >> #hex. Since his stream is already binary, he can also avoid converting his data to a string.
More context: I am using a ZLibReadStream and its upTo: method, which gives me a ByteString, not a ByteArray. I guess I could convert it to a ByteArray. But I still think there's a bug here: printing the hex value of a Character should add the leading zero, because they're represented by a full byte. So, I propose this change: Character>>hex ^value printStringBase: 16 nDigits: 2
On Mon, 20 Dec 2010, Geoffroy Couprie wrote:
Hello,
2010/12/20 Levente Uzonyi <leves@elte.hu>:
On Mon, 20 Dec 2010, Stéphane Ducasse wrote:
On Dec 19, 2010, at 9:55 PM, Geoffroy Couprie wrote:
Hello all,
I get a strange behaviour while trying to print hexadecimal values of a string.
Context: I get a SHA1 hash from a binary stream, store it into a string, and I want to display that string (using asHex).
Problem: for values inferior to 16, the leading zero is ignored. (15 -> 'F' instead of '0F').
indeed printStringHex prints F instead of 0F 15 printStringHex     'F' 15 hex     '16rF'
Geoffroy could you add a variant that produces the correct behavior with some tests?
No need to do that. As Sven pointed out, he can simply use ByteArray >> #hex. Since his stream is already binary, he can also avoid converting his data to a string.
More context: I am using a ZLibReadStream and its upTo: method, which gives me a ByteString, not a ByteArray. I guess I could convert it to a ByteArray.
But I still think there's a bug here: printing the hex value of a Character should add the leading zero, because they're represented by a full byte.
So, I propose this change:
Character>>hex ^value printStringBase: 16 nDigits: 2
What about this? (Character value: 12345) hex Levente
2010/12/20 Levente Uzonyi <leves@elte.hu>:
On Mon, 20 Dec 2010, Geoffroy Couprie wrote:
Hello,
2010/12/20 Levente Uzonyi <leves@elte.hu>:
On Mon, 20 Dec 2010, Stéphane Ducasse wrote:
On Dec 19, 2010, at 9:55 PM, Geoffroy Couprie wrote:
Hello all,
I get a strange behaviour while trying to print hexadecimal values of a string.
Context: I get a SHA1 hash from a binary stream, store it into a string, and I want to display that string (using asHex).
Problem: for values inferior to 16, the leading zero is ignored. (15 -> 'F' instead of '0F').
indeed printStringHex prints F instead of 0F 15 printStringHex     'F' 15 hex     '16rF'
Geoffroy could you add a variant that produces the correct behavior with some tests?
No need to do that. As Sven pointed out, he can simply use ByteArray >> #hex. Since his stream is already binary, he can also avoid converting his data to a string.
More context: I am using a ZLibReadStream and its upTo: method, which gives me a ByteString, not a ByteArray. I guess I could convert it to a ByteArray.
But I still think there's a bug here: printing the hex value of a Character should add the leading zero, because they're represented by a full byte.
So, I propose this change:
Character>>hex  ^value printStringBase: 16 nDigits: 2
What about this?
(Character value: 12345) hex
Huh, I forgot multibyte characters... Then would this be sufficient? Character>>hex value >255 ifTrue: [^value hex] ifFalse: [^value printStringBase: 16 nDigits: 2]
Huh, I forgot multibyte characters... Then would this be sufficient?
Character>>hex value >255 ifTrue: [^value hex] ifFalse: [^value printStringBase: 16 nDigits: 2]
geoffroy we cannot really change hex because hex returns 16rXXX and the other classes are consistent with that. (Character value: 12345) hex '16r3039' Integer>>hex "Print the receiver as hex, prefixed with 16r. DO NOT CHANGE THIS! The Cog VMMaker depends on this. Consider using any of printStringHex printStringBase: 16 printStringBase: 16 length: 8 padded: true storeStringHex storeStringBase: 16 storeStringBase: 16 length: 11 padded: true" ^self storeStringBase: 16 Now what we could have is another method named: xxPrintStringHex for example (first name that came to my mind) paddedPrintStringHex 1566 printStringHex '61E' 15 printStringHex 'F' 1566 paddedPrintStringHex '61E' 15 paddedPrintStringHex '0F' Or something like that. Stef
On Mon, Dec 20, 2010 at 1:31 PM, Stéphane Ducasse <stephane.ducasse@inria.fr> wrote:
Huh, I forgot multibyte characters... Then would this be sufficient?
Character>>hex   value >255     ifTrue: [^value hex]     ifFalse: [^value printStringBase: 16 nDigits: 2]
geoffroy
we cannot really change hex because hex returns     16rXXX
and the other classes are consistent with that.
(Character value: 12345) hex     '16r3039'
Integer>>hex     "Print the receiver as hex, prefixed with 16r.  DO NOT CHANGE THIS!  The Cog VMMaker depends on this.     Consider using any of         printStringHex         printStringBase: 16         printStringBase: 16 length: 8 padded: true         storeStringHex         storeStringBase: 16         storeStringBase: 16 length: 11 padded: true"     ^self storeStringBase: 16
Now what we could have is another method named:     xxPrintStringHex     for example (first name that came to my mind)     paddedPrintStringHex
1566 printStringHex '61E'
15 printStringHex  'F'
1566 paddedPrintStringHex '61E'
15 paddedPrintStringHex  '0F'
Or something like that.
I was using Pharo 1.1, where PrintStringHex is not implemented. In the patch for issue 3466, I modified printStringHex, but a new function including padding might be a better idea. Until Pharo 1.2 is published, I'll keep my custom code to display hexadecimal strings.
I don't want to start a philosophical discussion, but I'm puzzled: What constitutes "correct" behaviour in this case? Are you saying that 'correct' would be something like: 1 printStringHex '0F' and 1 hex '16r01' ?? Em 20/12/2010 06:10, Stéphane Ducasse < stephane.ducasse@inria.fr > escreveu: On Dec 19, 2010, at 9:55 PM, Geoffroy Couprie wrote:
Hello all,
I get a strange behaviour while trying to print hexadecimal values of a string.
Context: I get a SHA1 hash from a binary stream, store it into a string, and I want to display that string (using asHex).
Problem: for values inferior to 16, the leading zero is ignored. (15 -> 'F' instead of '0F').
indeed printStringHex prints F instead of 0F 15 printStringHex 'F' 15 hex '16rF' Geoffroy could you add a variant that produces the correct behavior with some tests?
I could modify SmallInteger>>printStringBase: to always include the leading zero, but I fear I'm going to break a lot of code doing that. Is there a better way to fix my problem? apart from using directly the following: aStream do:[:val | val printStringBase:16 nDigits:2]
Best regards,
Geoffroy
participants (6)
-
csrabak＠bol.com.br -
Geoffroy Couprie -
Levente Uzonyi -
Max Leske -
Stéphane Ducasse -
Sven Van Caekenberghe