c - Writing an integer to stdout in text form using only write() to do writing -

i'm trying write integer in stdout, in text form, write() function , possibly while/if.

i want write integer out in text form, it's human-readable, write out in binary form :

here tried :

main.c :

#include "my_put_nbr.h" int main() {     my_put_nbr(43);     return 0; } 

my_put_char.c :

#include <unistd.h> int my_put_nbr(int nb) {         write(1, &nb, sizeof(nb));         return 0; } 

so how can write integer out in text form write (or putchar) , conditions ?

ps : must not use other libraries, can't use printf or whatever !

my github : link

text mode , binary mode common in computer science, here reminder ones don't understand mean text form :

on unix system, when application reads file gets what's in file on disk , converse true writing. situation different in dos/windows world file can opened in 1 of 2 modes, binary or text. in binary mode system behaves in unix. on writing in text mode, nl (\n, ^j) transformed sequence cr (\r, ^m) nl.

quote cygwin.com

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maj :

i found answer:

#include "my_putchar.h" /* 0x2d = '-'  * 0x0 = nul */ int my_put_nbr(int n) {         if (n < 0)         {                 my_putchar(0x2d);                 n = -n;         }          if (n > 9)         {                 my_put_nbr(n/10);         }          my_putchar((n%10) + '0');          return 0; } 

write writing, writing non-visible characters. can see with:

./myprogram | od -tx1 

you need make number in n (int value 23) string "23" before printing it.

one way:

  char buffer[16];   snprintf(buffer, sizeof(buffer), "%d", n);   write(1, buffer, strlen(buffer));