#include <stdio.h>
#include <string.h>
 
int main(void) {
    char text[] = "thank you";
    int len = strlen(text);
 
    char hex[100], string[50];
 
    // Convert text to hex.
    int i,j;
 
    for ( i = 0, j = 0; i < len; i++, j+= 5) {
        sprintf(hex + j, "0x%02X ", text[i] );
        printf("0x%X ", text[i] );
    }
    printf("'%s' in hex is %s.\n", text, hex); //'thank you' in hex is 7468616e6b20796f75.
 
    // Convert the hex back to a string.
    len = strlen(hex);
    for (i = 0, j = 2; j < len; i++, j+= 5) {
        int val;
        sscanf(hex + j, "%2x", &val);
        string[i] = val;
    }
    string[i + 1] = '\0';
    printf("%s as a string is '%s'.\n", hex, string);
 
    return 0;
}
 

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