c - non-buffering stdin reading -

my test application is

#include <sys/types.h> #include <sys/wait.h> #include <signal.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <fcntl.h>  int main(int argc, char *argv[], char *envp[]) {   int fd[2];    if(pipe(fd) < 0) {      printf("can\'t create pipe\n");     exit(-1);    }    pid_t fpid = fork();   if (fpid == 0) {     close(0);     close(fd[1]);     char *s = (char *) malloc(sizeof(char));     while(1) if (read(fd[0], s, 1)) printf("%i\n", *s);   }   close(fd[0]);   char *c = (char *) malloc(sizeof(char));   while (1) {     if (read(0, c, 1) > 0) write(fd[1], c, 1);   }   return 0; } 

i want see char-code after each entered char. in fact *s printed after '\n' in console. seems stdin (file desc 0) buffered. read function buffer-less, isn't it? wrong.

upd: use linux.

so solution is

#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <termios.h>  int main(int argc, char *argv[], char *envp[]) {   int fd[2];    if(pipe(fd) < 0) {      printf("can\'t create pipe\n");     exit(-1);    }    struct termios term, term_orig;    if(tcgetattr(0, &term_orig)) {     printf("tcgetattr failed\n");     exit(-1);    }    term = term_orig;    term.c_lflag &= ~icanon;   term.c_lflag |= echo;   term.c_cc[vmin] = 0;   term.c_cc[vtime] = 0;    if (tcsetattr(0, tcsanow, &term)) {     printf("tcsetattr failed\n");     exit(-1);   }    pid_t fpid = fork();   if (fpid == 0) {     close(0);     close(fd[1]);     char *s = (char *) malloc(sizeof(char));     while(1) if (read(fd[0], s, 1)) printf("%i\n", *s);   }   close(fd[0]);   char *c = (char *) malloc(sizeof(char));   while (1) {     if (read(0, c, 1) > 0) write(fd[1], c, 1);   }   return 0; }  

unfortunately, behavior you're looking not possible standard ansi c, , default mode unix terminal i/o line-oriented, means need inputted \n character retrieve input. you'll need use terminal i/o facilities let program in non-canonical mode, each key-press triggers event. on linux/unix, can <termios.h> header, or ncurses library.