"hello world" to binary representation

[Andrea]

Hi, I'm a newbie i want to know how can i convert string to its binary
representation, i want to write a program where an example string
"hello world" is transformed in his binary representation
"11010010101...." and viceversa and then print on the stdout the
result of the two representation.

thanks in advance,
Andrea

 

[Salvatore Di Fazio]

Hi, I'm a newbie i want to know how can i convert string to its binary
representation, i want to write a program where an example string
"hello world" is transformed in his binary representation
"11010010101...." and viceversa and then print on the stdout the
result of the two representation.

thanks in advance,
Andrea

You can convert the char in the equivalent hex or int value and write
the value in binary representation

 

[Andrea]

You can convert the char in the equivalent hex or int value and write
the value in binary representation

ok i can use sprintf to transform a string to hexadecimal
representation bot how can i back to the original string, with the
hexadecimal representation???

 

[fdmfdmfdm]

ok i can use sprintf to transform a string to hexadecimal
representation bot how can i back to the original string, with the
hexadecimal representation???

I think what you can do is:

char c;
//assign your hex value to c here
printf("%c", c);

 

[Michal Nazarewicz]

ok i can use sprintf to transform a string to hexadecimal
representation bot how can i back to the original string, with the
hexadecimal representation???

Maybe that's what you want:

#v+
#include <stdio.h>
#include <stdlib.h>

int main(void) {
const char *message = "hello, world", *cc;
char msg_hex[25], msg_org[13], *c, *c2;

/* string -> hex */
for (cc = message, c = msg_hex; *cc; ++cc, c += 2) {
sprintf(c, "%02X", *cc);
}
*c = 0;

/* hex -> string */
for (c2 = msg_org, c = msg_hex; *c; c += 2, ++c2) {
char tmp = c[2];
c[2] = 0;
*c2 = strtol(c, 0, 16);
c[2] = tmp;
}
*c2 = 0;

/* print */
printf("message = %s\nmsg_hex = %s\nmsg_org = %s\n",
message, msg_hex, msg_org);
return 0;
}
#v-

 

[Michal Nazarewicz]

Maybe that's what you want:
#include <stdio.h>
#include <stdlib.h>

int main(void) {
const char *message = "hello, world", *cc;
char msg_hex[25], msg_org[13], *c, *c2;

/* string -> hex */
for (cc = message, c = msg_hex; *cc; ++cc, c += 2) {
sprintf(c, "%02X", *cc);
}
*c = 0;

/* hex -> string */
for (c2 = msg_org, c = msg_hex; *c; c += 2, ++c2) {
char tmp = c[2];
c[2] = 0;
*c2 = strtol(c, 0, 16);
c[2] = tmp;

I've just realised that in C99 you can replace those four lines with:

#v+
sscanf(c, "%2hhx", c2);
#v-

however %hhx requires unsigned char not char which may introduce bugs
on same implementations.