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POConvert ascii char[] to hexadecimal char[] in C
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copied!<p>I am trying to convert a char[] in ASCII to char[] in hexadecimal.</p> <p>Something like this:</p> <p>hello --> 68656C6C6F</p> <p>I want to read by keyboard the string. It has to be 16 characters long.</p> <p>This is my code now. I don't know how to do that operation. I read about strol but I think it just convert str number to int hex...</p> <pre><code>#include <stdio.h> main() { int i = 0; char word[17]; printf("Intro word:"); fgets(word, 16, stdin); word[16] = '\0'; for(i = 0; i<16; i++){ printf("%c",word[i]); } } </code></pre> <p>I am using fgets because I read is better than fgets but I can change it if necessary.</p> <p>Related to this, I am trying to convert the string read in a uint8_t array, joining each 2 bytes in one to get the hex number.</p> <p>I have this function which I am using a lot in arduino so I think it should work in a normal C program without problems.</p> <pre><code>uint8_t* hex_decode(char *in, size_t len, uint8_t *out) { unsigned int i, t, hn, ln; for (t = 0,i = 0; i < len; i+=2,++t) { hn = in[i] > '9' ? (in[i]|32) - 'a' + 10 : in[i] - '0'; ln = in[i+1] > '9' ? (in[i+1]|32) - 'a' + 10 : in[i+1] - '0'; out[t] = (hn << 4 ) | ln; printf("%s",out[t]); } return out; </code></pre> <p>}</p> <p>But, whenever I call that function in my code, I get a segmentation fault.</p> <p>Adding this code to the code of the first answer:</p> <pre><code> uint8_t* out; hex_decode(key_DM, sizeof(out_key), out); </code></pre> <p>I tried to pass all necessary parameters and get in out array what I need but it fails...</p>

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