Read on a file descriptor (parameter nbytes)

read_fd.c

/*
	idea was to resolve unexpected short-reads (when reading on stdin or pipe), read was returning less bytes than asked
	cf. https://stackoverflow.com/a/8975581/5183171
*/

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

char		*read_fd(int fd, int nbyte)
{
	char	*input;
	char	buffer[nbyte + 1];
	int	    bytes_read;
	int	    n;
	char	*tmp;

	n = 1;
	input = NULL;
	while ((bytes_read = read(fd, buffer, nbyte)) > 0)
	{
		buffer[bytes_read] = '\0';
      	tmp = malloc((n * nbyte + 1) * sizeof(char));
		tmp[0] = '\0';
		if (input)
		{
			strcpy(tmp, input);
			free(input);
		}
		input = strcat(tmp, buffer);
		n++;
	}
	if (bytes_read == -1)
		return (NULL);
	return (input);
}


#define NBYTE 100

int		main(void)
{
	printf("%s", read_fd(0, NBYTE));
	return (0);
}