lines.c

#include <unistd.h>
#include <errno.h>
#include "lines.h"


// Funcion para mandar mensajes por sockets
int sendMessage(int socket, char * buffer, int len) {
  int r;
  int l = len;

  do {
    r = write(socket, buffer, l);
    l = l - r;
    buffer = buffer + r;
  } while ((l > 0) && (r >= 0));

  if (r < 0)
    return (-1); /* fail */
  else
    return (0); /* full length has been sent */
}


// Función para recibir mensajes por sockets
int recvMessage(int socket, char * buffer, int len) {
  int r;
  int l = len;

  do {
    r = read(socket, buffer, l);
    l = l - r;
    buffer = buffer + r;
  } while ((l > 0) && (r >= 0));

  if (r < 0)
    return (-1); /* fallo */
  else
    return (0); /* full length has been receive */
}


// Funcion para recibir cadenas en sockets
ssize_t readLine(int fd, void * buffer, size_t n) {

  ssize_t numRead; /* num of bytes fetched by last read() */
  size_t totRead; /* total bytes read so far */
  char * buf;
  char ch;

  if (n <= 0 || buffer == NULL) {
    errno = EINVAL;
    return -1;
  }

  buf = buffer;
  totRead = 0;

  for (;;) {
    numRead = read(fd, & ch, 1); /* read a byte */

    if (numRead == -1) {
      if (errno == EINTR) /* interrupted -> restart read() */
        continue;
      else
        return -1; /* some other error */
    } else if (numRead == 0) {
      /* EOF */
      if (totRead == 0) /* no byres read; return 0 */
        return 0;
      else
        break;
    } else {
      /* numRead must be 1 if we get here*/
      if (ch == '\n')
        break;
      if (ch == '\0')
        break;
      if (totRead < n - 1) {
        /* discard > (n-1) bytes */
        totRead++;
        * buf++ = ch;
      }
    }
  }

  * buf = '\0';
  return totRead;
}