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Linuxbuilders
Joined: 20 Mar 2010
Posts: 193
Location: Auckland NZ
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| CHAR into HEX |
 Posted: Fri Aug 06, 2010 11:10 pm |
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Hi,
I am trying to do this but can't get it working, can you help please.
From terminal I enter ASCII: AADD and need to convert it into 0xAADD inside the program, so far I am getting 0x41 0x41 0x44 0x44 which is not what I am looking for.
I process a string where AADD is respectively string[1,2,3,4]
thnx
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Help "d" others and then you shell receive some help from "d" others. |
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newguy
Joined: 24 Jun 2004
Posts: 1903
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| Posted: Fri Aug 06, 2010 11:32 pm |
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| Code: | int32 my_hex_number = 0;
for (i = 0; i < 4; i++) {
if (string[i] >= 0x30 && string[i] <= 0x39) { // ascii 0 - 9
my_hex_number = (my_hex_number << 4) + (string[i] - 0x30);
}
else { // ascii a - f, but you should do a bounds check to be sure
my_hex_number = (my_hex_number << 4) + (string[i] - 0x37);
}
} |
This little bit of code just searches through your string[] array, iteratively subtracting the ascii "offset" from the entry in string[], and adding that to whatever was stored in my_hex_number previously, multiplied by 16 of course. |
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Linuxbuilders
Joined: 20 Mar 2010
Posts: 193
Location: Auckland NZ
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| Posted: Sat Aug 07, 2010 12:38 am |
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Thank you, with little mod it works well.
Thank you
_________________
Help "d" others and then you shell receive some help from "d" others. |
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Linuxbuilders
Joined: 20 Mar 2010
Posts: 193
Location: Auckland NZ
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| Posted: Sun Jun 16, 2013 3:28 am |
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Hey, found it in my "bag" of old code
| Code: |
ascii_convert(int value) { // ASCII conversion
int output = 0;
int strng = 0;
strng = value;
if (strng >= 0x30 && strng <= 0x39) { // ascii 0 - 9
output = strng - 0x30;
}
else { // ascii a - f
output = strng - 0x37;
}
return(output);
} |
_________________
Help "d" others and then you shell receive some help from "d" others. |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Sun Jun 16, 2013 4:00 pm |
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Thanks for sharing your code, but why after 3 years? And for a topic that has been discussed on this forum countless times?
Also, your posted code does not answer your original question:
- it converts only 1 hexadecimal character, not 4 as asked in the original topic.
- this code only handles lower case hexadecimal values but the original question was in capital characters.
Here is a more optimized solution: http://www.ccsinfo.com/forum/viewtopic.php?t=49776 |
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