Exit while loop on key in linux

Question

This program is a sound recorder+wav converter made in linux. I want to stop recording when I press the key 'u'. The problem is that it does not do that and it waits for the 'u' key+enter to exit the loop. Could you please tell me why, because I've been at it all morning.

#define ALSA_PCM_NEW_HW_PARAMS_API
#include <termios.h>
#include <stdio.h>
#include <alsa/asoundlib.h>
#include "fonctions_wav.h"

struct termios stdin_orig;
void term_reset(){
  tcsetattr(STDIN_FILENO, TCSANOW, &stdin_orig);
  tcsetattr(STDIN_FILENO, TCSAFLUSH, &stdin_orig);

void term_nonblocking() {
  struct termios newt;
  tcgetattr(STDIN_FILENO, F_SETFL, 0_NONBLOCK);
  newt = stding_orig;
  newt.c_lflag & = ~(ICANON | ECHO);
  tcsetattr(STDIN_FILENO, TCSANOW, &newt);

  atexit(term_reset);
}


int main() {
  long loops,nr_ech=0;
  char key='a';
  int rc;
  int size;
  snd_pcm_t *handle;
  snd_pcm_hw_params_t *params;
  unsigned int val;
  int dir;
  snd_pcm_uframes_t frames;
  char *buffer;
  FILE *f;
  int freq=16000;
  short bits=16, stereo=1;
  f=fopen("test.wav","wb");
  write_wav(f, &freq, &bits, &stereo, 10000);

  /* Open PCM device for recording (capture). */
  rc = snd_pcm_open(&handle, "default", SND_PCM_STREAM_CAPTURE, 0);
  if (rc < 0) {
    fprintf(stderr, "unable to open pcm device: %s\n", snd_strerror(rc));
    exit(1);
  }

  /* Allocate a hardware parameters object. */
  snd_pcm_hw_params_alloca(&params);

  /* Fill it in with default values. */
  snd_pcm_hw_params_any(handle, params);

  /* Set the desired hardware parameters. */

  /* Interleaved mode */
  snd_pcm_hw_params_set_access(handle, params, SND_PCM_ACCESS_RW_INTERLEAVED);

  /* Signed 16-bit little-endian format */
  snd_pcm_hw_params_set_format(handle, params, SND_PCM_FORMAT_S16_LE);

  /* One channel (monoo) */
  snd_pcm_hw_params_set_channels(handle, params, 1);

  /* 16000 bits/second sampling rate */
  val = 16000;
  snd_pcm_hw_params_set_rate_near(handle, params, &val, &dir);

  /* Set period size to 2048 frames. */
  frames = 2048;
  snd_pcm_hw_params_set_period_size_near(handle, params, &frames, &dir);

  /* Write the parameters to the driver */
  rc = snd_pcm_hw_params(handle, params);
  if (rc < 0) {
    fprintf(stderr, "unable to set hw parameters: %s\n", snd_strerror(rc));
    exit(1);
  }

  /* Use a buffer large enough to hold one period */
  snd_pcm_hw_params_get_period_size(params, &frames, &dir);
  size = frames * 2; /* 2 bytes/sample, 1 channels */
  buffer = (char *) malloc(size);

  while (key != 'u') {
    rc = snd_pcm_readi(handle, buffer, frames);
    if (rc == -EPIPE) {
      /* EPIPE means overrun */
      printf(stderr, "overrun occurred\n");
      snd_pcm_prepare(handle);
    } else if (rc < 0) {
      printf(stderr, "error from read: %s\n", snd_strerror(rc));
    } else if (rc != (int)frames) {
      printf(stderr, "short read, read %d frames\n", rc);
    }
    if (rc != size)
      printf(stderr, "short write: wrote %d bytes\n", rc);
fwrite(buffer, sizeof(char), rc, f);
nr_ech+=rc;
key=getchar();
  }
fclose(f);
f=fopen("test.wav","r+b");
write_wav(f, &freq, &bits, &stereo, nr_ech);
flcose(f);

  snd_pcm_drain(handle);
  snd_pcm_close(handle);
  free(buffer);

  return 0;
}