Conversion of char for hexa!?!?

[darkducke]

Friends, I have a function that it prints an image from an variable of the type byte.

 
 byte xRPrint []  = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
 PrintImage((byte *)xRPrint, 5, 128, 8); //function print image

until there all good

only that I go to send the content of the variable of a server, for socket in one string, Ex:

char xImage[] = "0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00"

as I make to catch the content of xImage and to place in each position of xRPrint

observing the value of string " 0x0F" and placing in the same position the referring value in hexa

understand?
it forgives my English!

thanks!

[whiteflags]

You need to turn the string back into a bunch of numbers. The underlying bit pattern for a number is different than the pattern for a glyph like 'A' or 'B' (which are both hex digits, bear with me).

There are C functions available to help you with your task. The easiest of which I can recommend is strtol. strtol, as implied by the name, takes a string and a radix, and attempts to convert the string data to a number representation.

You should look it up and devise a method to help yourself.

I made a demonstration for you, take a look with your debugger:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

int main ( void ) 
{
    const char * receev_me = "0xDE 0xAD 0xBE 0xAF 0x00";   /** some data **/
    char * receev_me_pos = NULL;
    unsigned long i = 0;
    unsigned char converted[16];  /** a big enough space to hold actual bytes**/
    int done = 0;                 /** loop control **/

    /** set to all bits zero **/
    memset( converted, '\0', sizeof converted );

    /** parse the hexa bytes with strtol **/
    while ( !done ) {
        unsigned char byt = ( unsigned char )strtol( receev_me, &receev_me_pos, 16 );
        /** strtol will point to where conversion ended. **/
        /** if the number was done sucessfully, try to store it. **/
        if ( receev_me_pos != receev_me && ( isspace( *receev_me_pos ) || *receev_me_pos == '\0' ) ) {
            if ( i >= sizeof converted ) {
                fprintf( stderr, "No more room to store converted data!!!\n" );
                done = !done;
            }
            converted[i++] = byt;
            receev_me = receev_me_pos;
        }
        else {
            /** normal completion - nothing to parse **/
            done = !done;
        }
    }
    return 0;
}

This may or may not be exactly what you are looking for but I'm confident you'll go far with this help.

[darkducke]

accurate, it was this same, it correctly printed as img printed in the format

byte [] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}

tnx tnx tnx!!!!